# Patent

## Title
Methods for making lignocellulose containing composite products

## Abstract

Methods for making composite products are provided. In at least one specific embodiment, the method can include combining a plurality of lignocellulose substrates, a free radical precursor, and a polyphenolic material to produce a mixture. The polyphenolic material can be in a liquid form, a solid form, or both when combined to produce the mixture. The method can also include maintaining the mixture at a temperature of less than 60° C. for at least 10 minutes while retaining at least 11 wt % of the free radical precursor charged to the mixture. The mixture can also include heating the mixture comprising at least 11 wt % of the free radical precursors charged to the mixture to a temperature of at least 60° C. to about 300° C. to produce a composite product.

## Background
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent application Ser. No. 14/040,791, filed on Sep. 30, 2013, which claims priority to U.S. Provisional Patent Application Ser. No. 61/708,395, filed Oct. 1, 2012, which are incorporated by reference herein.


BACKGROUND
Field
Embodiments described generally relate to methods for making lignocellulose composite products. More particularly, such embodiments relate to methods for making lignocellulose composite products with one or more polyphenolic materials and one or more free radical precursors.
Description of the Related Art
The production of lignocellulose composite products requires an adhesive or binder to bond the discrete, particulates, fibers, veneers, or other substrates to one another. Typical lignocellulose composite products include particleboard, fiberboard, plywood, and the like. Conventional binders used in the production of these products frequently contain formaldehyde based resins such as urea-formaldehyde (UF), melamine-formaldehyde (MF), melamine-urea-formaldehyde (MUF), and phenol-formaldehyde (PF) binders. While formaldehyde based resins produce finished products having desirable properties, such as strength, these binders also release formaldehyde into the environment during the production of the binder, curing of the binder/composite product, as well as, from the final product made using the binder.
Various techniques have been used to reduce the amount of formaldehyde released from formaldehyde based resins. For example, the addition of formaldehyde scavengers to the resin and/or various modifications to the particular synthesis steps used to make the formaldehyde based resin, such as the addition of urea as a reactant late in the binder synthesis, are often used in an attempt to reduce formaldehyde emission. These attempts to reduce formaldehyde emission, however, are accompanied with undesirable effects such as longer cure time, reduced resin shelf-life, reduced product strength, reduced tolerance for processing variations, and/or inferior moisture resistance.
There is a need, therefore, for improved methods for making lignocellulose containing composite products having reduced or no formaldehyde emission.
SUMMARY
Methods for making composite products are provided. In at least one specific embodiment, a method can include combining a plurality of lignocellulose substrates, a free radical precursor, and a polyphenolic material to produce a mixture. The polyphenolic material can be in a liquid form, a solid form, or both when combined to produce the mixture. The method can also include maintaining the mixture at a temperature of less than 60° C. for at least 10 minutes while retaining at least 11 wt % of the free radical precursor charged to the mixture. The mixture can also include heating the mixture comprising at least 11 wt % of the free radical precursors charged to the mixture to a temperature of at least 60° C. to about 300° C. to produce a composite product.
In at least one specific embodiment, a method for making a composite product can include combining a plurality of lignocellulose substrates, a free radical precursor, and a polyphenolic material to produce a mixture. The polyphenolic material can be in a solid form when combined to produce the mixture. The method can also include heating the mixture to produce a composite product.
In at least one specific embodiment, a composite product can include an at least partially cured composition having a density of less than 1 g/cm3 and an internal bond strength of at least 0.35 MPa. The composition, prior to curing, can include a plurality of lignocellulose substrates, a free radical precursor, and a polyphenolic material. The polyphenolic material can be in a liquid form, a solid form, or both when combined with the plurality of lignocellulose substrates and the free radical precursor.


DETAILED DESCRIPTION
In one or more embodiments, a method for making a composite product can include combining a plurality of lignocellulose substrates, one or more free radical precursors, and one or more polyphenolic materials to produce a mixture. The mixture can be heated to produce a composite product. The plurality of lignocellulose substrates, free radical precursor, and polyphenolic material can be mixed, blended, stirred, contacted, or otherwise combined with one another to produce the mixture. The polyphenolic material can be or include one or more polyphenolic compounds. The polyphenolic compound can be or include a compound having at least two hydrogen atoms that are abstractable in the presence of hydroxyl radicals. The polyphenolic material can be, but is not limited to, one or more lignins, one or more tannins, one or more novolac resins, one or more modified phenol formaldehyde resins, bisphenol A, humic acids, salts thereof, acids thereof, hydrates thereof, or any mixture thereof.
The polyphenolic material or compound can be in a liquid form, a solid form, or both when combined with the plurality of lignocellulose substrates and the free radical precursor. The liquid form can include solutions, suspensions, slurries, dispersions, emulsions, inverse emulsions, or other liquid forms. In at least one example, a liquid form of the polyphenolic material can be a solution, e.g., an aqueous solution. For example, one or more polyphenolic compounds can be dissolved or at least partially dissolved in one or more liquids to produce a solution. In another example, the liquid form of the polyphenolic material can be or include a solid polyphenolic material suspended, dispersed, or otherwise distributed within a liquid medium, e.g., a suspension, slurry, or dispersion. In another example, the liquid form of the polyphenolic material can be or can essentially be composed of one or more polyphenolic compounds. Said another way, the polyphenolic material can be a liquid in the absence or substantial absence of any liquid medium as compared to being dissolved in, dispersed in, suspended in, mixed with, or otherwise combined with a liquid medium. In another example, the polyphenolic material can be a water insoluble polyphenolic material.
The mixture can also be referred to as a “furnish,” “blended furnish,” “resinated mixture,” or “resinated furnish.” The mixture can be heated to produce the lignocellulose containing composite product or “composite product.” For example, the mixture can be heated to a temperature of 60° C., about 90° C., about 120° C., about 150° C., or about 160° C. to about 170° C., about 200° C., about 230° C., about 260° C., or about 300° C. to produce the composite product. In another example, the mixture can be heated to a temperature of at least 60° C., at least 70° C., at least 80° C., at least 90° C., at least 100° C., at least 110° C., at least 120° C., at least 130° C., or at least 140° C. to about 150° C., about 155° C., about 160° C., about 165° C., about 170° C., about 180° C., about 200° C., about 225° C., about 250° C., about 275° C., or about 300° C. In another example, the mixture can be heated to a temperature of about 140° C. to about 200° C., about 155° C. to about 175° C., about 160° C. to about 210° C., about 160° C. to about 175° C., or about 145° C. to about 225° C.
In one or more embodiments, the mixture can be heated in an atmosphere of ambient air. In one or more embodiments, the mixture can be heated in an inert atmosphere or substantially an inert atmosphere such as nitrogen. If the mixture is heated in a substantially inert atmosphere the amount of oxygen can be less than 5 mol %, less than 3 mol %, less than 1 mol %, less than 0.5 mol %, or less than 0.1 mol % oxygen. Suitable inert gases can include, but are not limited to, nitrogen, argon, helium, or any mixture thereof.
Heating the mixture can cause or promote the at least partial curing of the mixture to produce the composite product. As used herein, the terms “curing,” “cured,” “at least partially curing,” “at least partially cured,” and similar terms are intended to refer to the structural and/or morphological change that occurs in the mixture, such as by covalent chemical reaction (crosslinking), ionic interaction or clustering, phase transformation or inversion, and/or hydrogen bonding when the is subjected to conditions sufficient, e.g., sufficiently heated, to cause the properties of a flexible, porous substrate, such as a nonwoven mat or blanket of lignocellulose substrates and/or a rigid or semi-rigid substrate, such as a wood or other lignocellulose containing board or sheet, to which an effective amount of the free radical precursor and the polyphenolic material has been applied, to be altered.
When the mixture is heated, the mixture can contain at least a portion of the free radical precursor initially added to and present in the mixture. Said another way, at least a portion of the free radical precursor can remain unreacted or otherwise in the same form as when combined with the additional components of the mixture at least until the mixture is heated to an elevated temperature such as about 60° C. or greater. For example, if the free radical precursor includes one or more oxidants, e.g., hydrogen peroxide (H2O2), at least a portion of the oxidant in the form of hydrogen peroxide (H2O2) can be present when heating of the mixture is initiated or started. In one or more embodiments, the mixture can contain at least 11 wt %, at least 13 wt %, at least 15 wt %, at least 20 wt %, at least 25 wt %, at least 30 wt %, at least 35 wt %, at least 40 wt %, at least 45 wt %, at least 50 wt %, at least 55 wt %, at least 60 wt %, at least 65 wt %, or at least 70 wt % of the total or initial amount of free radical precursor initially present in the mixture, e.g., the amount of the free radical precursor combined with the plurality of lignocellulose substrates to produce the mixture, when the mixture is heated to a temperature of at least 60° C. In another example, the amount of the free radical precursor present when the mixture is heated to a temperature of at least 60° C. can be at least 11 wt %, at least 13%, at least 15 wt %, at least 20 wt %, at least 25 wt %, at least 30 wt %, at least 35 wt %, at least 40 wt %, at least 45 wt %, at least 50 wt %, at least 55 wt %, at least 60 wt %, at least 65 wt %, or at least 70 wt % of the one or more free radical precursors combined with the plurality of lignocellulose substrates. In still another example, the amount of the free radical precursor present when the mixture is heated to a temperature of at least 60° C., at least 65° C., or at least 70° C. can be at least 11 wt %, at least 13%, at least 15 wt %, at least 20 wt %, at least 25 wt %, at least 30 wt %, at least 35 wt %, at least 40 wt %, at least 45 wt %, at least 50 wt %, at least 55 wt %, at least 60 wt %, at least 65 wt %, or at least 70 wt % of the one or more free radical precursors combined with the plurality of lignocellulose substrates. In another example, the mixture can contain about 11% to about 95%, about 15% to about 85%, about 20% to about 90%, about 30% to about 80%, about 11% to about 100%, about 35% to about 75%, about 40% to about 70%, about 50% to about 70%, about 60% to about 80%, about 65% to about 85%, or about 30% to about 95% of the total amount of free radical precursor initially present in the mixture when the mixture is heated. In at least one specific example, if the mixture can include about 5 wt % free radical precursor, based on the dry weight of the lignocellulose substrates when the mixture is initially formed and when the mixture is heated to a temperature of 60° C. or more at least 11% of the free radical precursor can be present in the mixture. Said another way, if the mixture contains about 5 wt % of the one or more free radical precursors, based on the dry weight of the lignocellulose substrates, upon preparation or formation of the mixture, when heating the mixture is initiated or started, the mixture can have a free radical precursor concentration of at least 11% of the initial 5 wt % or 0.55 wt %, based on the dry weight of the lignocellulose substrates.
In one or more embodiments, the amount of the one or more free radical precursors present when the mixture is heated, e.g., to a temperature of about 60° C. to about 300° C., can be at least 0.5 wt %, at least 0.7 wt %, at least 1 wt %, at least 1.2 wt %, at least 1.5 wt %, at least 1.7 wt %, at least 2 wt %, at least 2.2 wt %, at least 2.5 wt %, at least 2.7 wt %, at least 3 wt %, at least 3.2 wt %, at least 3.5 wt %, at least 3.7 wt %, at least 4 wt %, at least 4.2 wt %, at least 4.5 wt %, at least 4.7 wt %, or at least 5 wt %, based on the dry weight of the plurality of lignocellulose substrates. For example, the amount of the one or more free radical precursors present when the mixture is heated can be about 1 wt %, about 1.5 wt %, about 1.6 wt %, about 1.8 wt %, or about 2.1 wt % to about 5 wt %, about 7 wt %, about 10 wt %, about 15 wt %, about 20 wt % or more, based on the dry weight of the plurality of lignocellulose substrates. In another example, the amount of the one or more free radical precursors present when the mixture is heated can be about 1 wt % to about 10 wt %, about 1.5 wt % to about 7 wt %, about 2 wt % to about 6 wt %, about 2.5 wt % to about 8 wt %, about 3 wt % to about 5.5 wt %, about 4 wt % to about 6.5 wt %, about 2.2 wt % to about 11 wt %, or about 2.3 wt % to about 6.3 wt %, based on the dry weight of the plurality of lignocellulose substrates.
The mixture can be heated as soon as the mixture is formed. The mixture can be kept, held, or otherwise maintained at a temperature of less than 60° C. for a period of time prior to heating the mixture to a temperature of at least 60° C. At least one way an exothermic reaction between the components of the mixture can be substantially and significantly slowed and/or prevented such that the mixture does not significantly increase in temperature until the mixture is intentionally heated can be to select an appropriate free radial precursor or mixture of free radical precursors. In other words, the temperature of the mixture, without external heat directed to the mixture, can remain free from or substantially free from the development of an exotherm by selectively selecting an appropriate free radical precursor(s). The particular temperature of the mixture during the time period before heating can depend, at least in part, on the ambient or environmental temperature where the mixture is located. In one or more embodiments, the mixture can be maintained at a temperature of less than 60° C. without any intentional removal of heat therefrom. In one or more embodiments, the mixture can be maintained at a temperature of less than 60° C. with removal of heat therefrom, e.g., the mixture can be located within a refrigeration device and/or a cooled fluid such as chilled air can be directed toward and/or passed through the mixture. In one or more embodiments, the mixture can be maintained at a temperature of less than 60° C. by controlling or adjusting a water concentration of the mixture. For example, increasing the water concentration of the mixture can reduce, inhibit, or prevent the mixture from undergoing an exothermic reaction.
Prior to heating the mixture to a temperature of at least 60° C., the mixture can be maintained at a temperature of less than 60° C., less than 55° C., less than 50° C., less than 45° C., less than 40° C., less than 35° C., or less than 30° C. for at least 10 minutes, at least 13 minutes, at least 15 minutes, at least 17 minutes, at least 20 minutes, at least 23 minutes, at least 25 minutes, at least 27 minutes, at least 30 minutes, at least 33 minutes, at least 35 minutes, at least 37 minutes, at least 40 minutes, at least 43 minutes, at least 45 minutes, at least 47 minutes, at least 50 minutes, at least 53 minutes, at least 55 minutes, at least 57 minutes, or at least 60 minutes. For example, the mixture can be maintained at a temperature of less than 60° C. for at least 10 minutes to about 30 minutes, at least about 15 minutes to about 35 minutes, at least about 20 minutes to about 40 minutes, at least about 18 minutes to about 45 minutes, or at least about 15 minutes to about 40 minutes prior to heating the mixture to a temperature of at least 60° C. In another example, the mixture can be maintained at a temperature of less than 60° C. for at least 10 minutes, about 30 minutes, about 45 minutes, about 1 hour, about 2 hours, about 3 hours, about 5 hours, about 12 hours, about 18 hours, about 24 hours, or about 30 hours prior to heating the mixture to a temperature of at least 60° C.
Prior to heating the mixture to a temperature of at least 60° C., the amount of energy generated from the mixture due to exothermic reaction(s) can be less than 35 cal/g of the mixture, less than 30 cal/g of the mixture, less than 25 cal/g of the mixture, less than 23 cal/g of the mixture, less than 20 cal/g of the mixture, less than 18 cal/g of the mixture, less than 16 cal/g of the mixture, less than 15 cal/g of the mixture, less than 14 cal/g of the mixture, or less than 13.8 cal/g of the mixture. For example, prior to heating the mixture to a temperature of at least 60° C., the amount of energy generated from the mixture due to exothermic reaction(s) can be less than 14 cal/g, less than 13.5 cal/g, less than 13 cal/g, less than 12.5 cal/g, less than 12 cal/g, less than 11.5 cal/g, less than 11 cal/g, less than 10.5 cal/g, less than 10 cal/g, less than 9.5 cal/g, less than 9 cal/g, less than 8.5 cal/g, less than 8 cal/g, less than 7.5 cal/g, less than 7 cal/g, less than 6.5 cal/g, less than 6 cal/g, less than 5.5 cal/g, less than 5 cal/g, less than 4.5 cal/g, less than 4 cal/g, less than 3.5 cal/g, less than 3 cal/g, less than 2.5 cal/g. less than 2 cal/g, less than 1.5 cal/g, less than 1 cal/g, or less than 0.5 cal/g of the mixture.
Composite products in the shape or form of a panel, sheet, board, or the like can be in the form of a rectangular prism that includes six outer surfaces, i.e., three pairs of oppositely facing surfaces. The first pair of oppositely facing surfaces of the composite product can include a first or “top” surface and an opposing second or “bottom” surface. The second and third pairs of oppositely facing surfaces of the composite product can be referred to as the “side surfaces” that have a surface area less than the surface area of the first and second surfaces. As such, composite products in the shape or form of a panel, sheet, board, or the like can have an average thickness, where the average thickness is the length or distance between the first and second surfaces.
If the composite product is in the form of a panel, sheet, board, or the like, the mixture can be heated about 5 seconds per millimeter (s/mm), about 10 s/mm, about 12 s/mm, or about 15 s/mm to about 17 s/mm, about 19 s/mm, about 21 s/mm, about 23 s/mm, about 25 s/mm, about 27 s/mm, about 30 s/mm, about 35 s/mm, about 40 s/mm, about 50 s/mm, or about 60 s/mm, where the length refers to the average thickness of the composite product. For example, the mixture can be heated for a time of about 7 s/mm to about 27 s/mm, about 9 s/mm to about 24 s/mm, about 11 s/mm to about 22 s/mm, about 8 s/mm to about 20 s/mm, about 14 s/mm to about 18 s/mm, about 6 s/mm to about 14 s/mm, about 10 s/mm to about 18 s/mm, or about 10 s/mm to about 16 s/mm, where the length refers to the average thickness of the composite product. In another example, the mixture can be heated for a time less than 22 s/mm, less than 20 s/mm, less than 18 s/mm, less than 17 s/mm, less than 16 s/mm, less than 15 s/mm, less than 14 s/mm, less than 13 s/mm, or less than 12 s/mm, where the length refers to the average thickness of the composite product. In one specific example, a composite product in the form of a panel, sheet, board, or the like and having an average thickness of about 15 mm and subjected to a total heating time of about 4 minutes would correspond to heating the mixture for about 16 s/mm. In at least one specific example, the mixture can be heated to a temperature of about 160° C. to about 170° C. for a time of 13 s/mm to about 19 s/mm.
Pressure can optionally be applied to the mixture before, during, and/or after the mixture is heated to produce the composite product. For example, if the desired composite product shape or structure is a panel, sheet, board, or the like, an amount of the mixture sufficient to produce a composite product of the desired size, can be transported, directed, placed, introduced, disposed, or otherwise located within a press capable of pressing the mixture before the mixture is heated and/or when the mixture is heated. The press can be an open press or a closed press. In at least one specific embodiment, an open press can be used to press the mixture when the mixture is heated, e.g., to a temperature of about 100° C. to about 250° C. In another example, the mixture can be extruded through a die (extrusion process) and heated to produce the composite product. The mixture can be pressed under a pressure of about 0.5 MPa, about 1 MPa, about 3 MPa, or about 5 MPa to about 7 MPa, about 9 MPa, or about 11 MPa.
Illustrative open presses can be as discussed and described in U.S. Pat. Nos. 4,017,248; 5,337,655; 5,611,269; 5,950,532; 6,098,532; and 6,782,810. Suitable, commercially available, open presses can include, but are not limited to, the CONTIROLL® press available from Siempelkamp and the CPS press available from Dieffenbacher.
The pH of the mixture can be acidic, neutral, or basic. For example, the pH of the mixture can be about 1, about 2, or about 3 to about 4, about 5, about 6, about 7, or about 8, with suitable ranges including the combination of any two values. In another example, the pH of the mixture can be about 1 to about 6, about 1.5 to about 5.5, about 2.5 to about 4.5, about 2 to about 3.5, or about 2.5 to about 3.5. The pH of the mixture can be adjusted to any desired pH by combining one or more base compounds, one or more acid compounds, or a combination of one or more base compounds and one or more acid compounds therewith.
Illustrative base compounds that can be used to adjust the pH of the mixture can include, but are not limited to, hydroxides, carbonates, ammonia, amines, any combination thereof, or any mixture thereof. Illustrative hydroxides can include, but are not limited to, sodium hydroxide, potassium hydroxide, ammonium hydroxide (e.g., aqueous ammonia), lithium hydroxide, and cesium hydroxide. Illustrative carbonates can include, but are not limited to, sodium carbonate, sodium bicarbonate, potassium carbonate, and ammonium carbonate. Illustrative amines can include, but are not limited to, trimethylamine, triethylamine, triethanolamine, diisopropylethylamine (Hunig's base), pyridine, 4-dimethylaminopyridine (DMAP), and 1,4-diazabicyclo[2.2.2]octane (DABCO).
Illustrative acid compounds that can be used to adjust the pH of the mixture can include, but are not limited to, one or more mineral acids, one or more organic acids, one or more acid salts, any combination thereof, or any mixture thereof. Illustrative mineral acids can include, but are not limited to, hydrochloric acid, nitric acid, phosphoric acid, sulfuric acid, any combination thereof, or any mixture thereof. Illustrative organic acids can include, but are not limited to, acetic acid, formic acid, citric acid, oxalic acid, uric acid, lactic acid, any combination thereof, or any mixture thereof. Illustrative acid salts can include, but are not limited to, ammonium sulfate, sodium bisulfate, sodium metabisulfite, any combination thereof, or any mixture thereof.
The mixture can include one or more liquid mediums. The one or more liquid mediums can be present in any one or more of the lignocellulose substrates, the free radical precursor, and/or the polyphenolic material. The liquid medium can be or include, but is not limited to, water, alcohols, glycols, acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide, N-methylpyrrolidone, any combination thereof, or any mixture thereof. Suitable alcohols can include, but are not limited to, methanol, ethanol, propanol, isopropanol, butanol, iomers thereof, or any mixture thereof. Suitable glycols can include, but are not limited to, ethylene glycol, propylene glycol, or a combination thereof. As used herein, the terms “aqueous medium” and “aqueous liquid” can be or include water and/or mixtures composed of water and/or other water-miscible solvents. Illustrative water-miscible solvents can include, but are not limited to, alcohols, ethers, amines, other polar aprotic solvents, and the like. In at least one example, the liquid medium can be water and the catalyst, the oxidant, and/or the polyphenolic material can be combined with water.
The mixture can have a liquid, e.g., water, content of about 1 wt %, about 3 wt %, about 5 wt %, or about 10 wt % to about 12 wt %, about 14 wt %, about 16 wt %, about 18 wt %, about 20 wt %, about 22 wt %, or about 24 wt %, based on the total weight of the mixture, with suitable ranges including the combination of any two values. For example, when the mixture contains water as the liquid, the mixture can have a moisture content of about 10 wt % to about 25 wt %, about 12 wt % to about 20 wt %, about 11 wt % to about 19 wt %, about 13 wt % to about 18 wt %, about 15 wt % to about 18 wt %, about 12 wt % to about 17 wt %, about 5 wt % to about 22 wt %, or about 14 wt % to about 17 wt %, based on the total weight of the mixture.
The components of the mixture can be combined simultaneously or in any order or sequence with respect to one another. For example, the free radical precursor and, if present, the polyphenolic material can be combined with the lignocellulose substrates simultaneously. In another example, the free radical precursor can be combined with the lignocellulose substrates to produce a first mixture and then the polyphenolic material can be combined with the first mixture to produce the mixture. In another example, the polyphenolic material can be combined with the lignocellulose substrates to produce a first or partial mixture, and then the free radical precursor can be combined with the first or partial mixture to produce the mixture.
If the free radical precursor includes two or more components, e.g., a catalyst and an oxidant, the components of the free radical precursor can be combined with the lignocellulose substrates and the polyphenolic material in any order or sequence. For example, if the free radical precursor includes a catalyst and an oxidant, the catalyst can be combined with the lignocellulose substrates to produce a first partial mixture and the oxidant can be combined with the first partial mixture to produce the mixture or vice versa. In another example, the catalyst and the polyphenolic material can be combined with one another to produce a first partial mixture, the first partial mixture can be combined with the lignocellulose substrates to produce a second partial mixture, and the oxidant can be combined with the second partial mixture to produce the mixture. In still another example, the oxidant and the polyphenolic material can be combined with one another to produce a first partial mixture, the first partial mixture can be combined with the lignocellulose substrates to produce a second partial mixture, and the catalyst can be combined with the second partial mixture to produce the mixture. In another example, the oxidant and the catalyst can be combined with one another to produce a first partial mixture, the first partial mixture can be combined with the lignocellulose substrates to produce a second partial mixture, and the polyphenolic material can be combined with the second partial mixture to produce the mixture.
The components of the mixture can be introduced or otherwise contacted with one another via any suitable delivery method. For example, the lignocellulose substrates can be in a vessel or other container and the free radical precursor, and, if present, the compound having at least two hydrogen atoms that are extractable in the presence of hydroxyl radicals can be sprayed or otherwise directed onto the lignocellulose substrates to produce the mixture. In another example, the free radical precursor, and, if present, the compound having at least two hydrogen atoms that are extractable in the presence of hydroxyl radicals can be poured or brushed onto the lignocellulose substrates. In another example, the lignocellulose substrates can be directed, transported, introduced, or otherwise conveyed into a vessel already containing any one or more of the other components of the mixture. Said another way, the lignocellulose substrates can be dipped, soaked, or otherwise contacted with the free radical precursor and the polyphenolic compound.
As used herein, the term free radical precursor refers to any compound or mixture of compounds that can generate radicals when subjected to predetermined conditions. For example, the free radical precursor can be a compound or mixture of compounds that can generate radicals when heated to a predetermined temperature. In another example, the free radical precursor can be a compound or mixture of compounds that can generate radicals when hydrogen peroxide (oxidant) is subjected to reaction with one or more transition metals (catalyst).
The amount of free radical precursor present in the mixture can depend, at least in part, on the particular composition of the free radical precursor, lignocellulose substrates, and/or, if present, the polyphenolic material and, thus, can widely vary. For example, the amount of radical precursor in the mixture can be about 1 wt % to about 200 wt %, based on the dry weight of the lignocellulose substrates. In another example, the amount of radical precursor in the mixture can be about 1 wt %, about 5 wt %, about 10 wt %, or about 20 wt % to about 80 wt %, about 100 wt %, about 120 wt %, or about 150 wt %, based on the dry weight of the lignocellulose substrates, with suitable ranges including the combination of any two values. In another example, the radical precursor can be present in the mixture in an amount of about 0.1 wt % to about 30 wt %, about 1 wt % to about 20 wt %, about 5 wt % to about 50 wt %, about 10 wt % to about 70 wt %, about 0.5 wt % to about 25 wt %, about 3 wt % to about 6 wt %, or about 2 wt % to about 8 wt %, based on the dry weight of the lignocellulose substrates. In still another example, the radical precursor can be present in the mixture in amount of about 0.1 wt % to about 10 wt %, about 1 wt % to about 12 wt %, about 2 wt % to about 9 wt %, about 3 wt % to about 9 wt %, about 5 wt % to about 15 wt %, about 4 wt % to about 6 wt %, about 8 wt % to about 20 wt %, or about 2 wt % to about 10 wt %, based on the dry weight of the lignocellulose substrates.
In one or more embodiments, the amount of the free radical precursor in the mixture can be about 3 wt %, about 4 wt %, about 5 wt %, about 6 wt %, about 7 wt %, about 8 wt %, about 9 wt %, or about 10 wt % and prior to heating the mixture to a temperature of at least 60° C., the amount of energy generated from the mixture due to any exothermic reaction(s) can be less than 75 cal/g of the mixture, less than 69 cal/g of the mixture, less than 62 cal/g of the mixture, less than 55 cal/g of the mixture, less than 48 cal/g of the mixture, less than 42 cal/g of the mixture, less than 34 cal/g of the mixture, less than 27 cal/g of the mixture, less than 20 cal/g of the mixture, or less than 13 cal/g of the mixture. For example, the amount of the free radical precursor in the mixture can be about 3 wt %, and prior to heating the mixture to a temperature of at least 60° C., the amount of energy generated from the mixture due to exothermic reaction(s) can be less than 21 cal/g of the mixture, less than 20 cal/g of the mixture, less than 18 cal/g of the mixture, less than 16 cal/g of the mixture, less than 14 cal/g of the mixture, less than 12 cal/g of the mixture, less than 10 cal/g of the mixture, less than 8 cal/g of the mixture, less than 6 cal/g of the mixture, or less than 4 cal/g of the mixture. In another example, the amount of the free radical precursor in the mixture can be about 4 wt % and prior to heating the mixture to a temperature of at least 60° C., the amount of energy generated from the mixture due to exothermic reaction(s) can be less than 28 cal/g of the mixture, less than 26 cal/g of the mixture, less than 24 cal/g of the mixture, less than 22 cal/g of the mixture, less than 20 cal/g of the mixture, less than 18 cal/g of the mixture, less than 16 cal/g of the mixture, less than 14 cal/g of the mixture, less than 12 cal/g of the mixture, or less than 10 cal/g of the mixture. In another example, the amount of the free radical precursor in the mixture can be about 5 wt % and prior to heating the mixture to a temperature of at least 60° C., the amount of energy generated from the mixture due to exothermic reaction(s) can be less than 35 cal/g of the mixture, less than 33 cal/g of the mixture, less than 31 cal/g of the mixture, less than 29 cal/g of the mixture, less than 27 cal/g of the mixture, less than 25 cal/g of the mixture, less than 23 cal/g of the mixture, less than 21 cal/g of the mixture, less than 19 cal/g of the mixture, or less than 17 cal/g of the mixture. In another example, the amount of the free radical precursor in the mixture can be about 6 wt % and prior to heating the mixture to a temperature of at least 60° C., the amount of energy generated from the mixture due to exothermic reaction(s) can be less than 42 cal/g of the mixture, less than 40 cal/g of the mixture, less than 38 cal/g of the mixture, less than 36 cal/g of the mixture, less than 34 cal/g of the mixture, less than 32 cal/g of the mixture, less than 30 cal/g of the mixture, less than 28 cal/g of the mixture, less than 26 cal/g of the mixture, or less than 24 cal/g of the mixture. In another example, the amount of the free radical precursor in the mixture can be about 7 wt % and prior to heating the mixture to a temperature of at least 60° C., the amount of energy generated from the mixture due to exothermic reaction(s) can be less than 49 cal/g of the mixture, less than 45 cal/g of the mixture, less than 40 cal/g of the mixture, less than 35 cal/g of the mixture, less than 30 cal/g of the mixture, less than 25 cal/g of the mixture, less than 20 cal/g of the mixture, less than 15 cal/g of the mixture, less than 10 cal/g of the mixture, or less than 8 cal/g of the mixture.
Illustrative free radical precursors can include, but are not limited to, one or more azo compounds, one or more oxidants, a combination or mixture of one or more catalysts and one or more oxidants, or any mixture or combination thereof. Illustrative azo compounds can be represented by the general Formula R—N═N—R′, where R and R′ can independently be substituted aryl or substituted alkyl. The term “aryl” refers to an aromatic substituent containing a single aromatic ring or multiple aromatic rings that are fused together, linked covalently, or linked to a common group such as a methylene or ethylene moiety. More specific aryl groups contain one aromatic ring or two or three fused or linked aromatic rings, e.g., phenyl, naphthyl, biphenyl, anthracenyl, phenanthrenyl, and the like. In one or more embodiments, aryl substituents can have 1 carbon atom to about 20 carbon atoms. The alkyl can include branched or unbranched alkyls having 1 carbon atom to about 15 carbon atoms or 1 carbon atom to about 8 carbon atoms. Illustrative alkyls can include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, isobutyl, n-butyl, sec butyl, t-butyl, n-pentyl, n-hexyl, ethylhexyl, and isomers thereof. Suitable azo compounds can include, but are not limited to, azobisisobutyronitrile (AIBN).
The catalyst, if present in the free radical precursor, can also be referred to as an initiator, a promoter, a reducer, and/or an accelerator. Suitable catalysts can be or include, but are not limited to, metal ions, tertiary amines, polymeric tertiary amines, polyamines, phosphates, bisulfites, metabisulfites, tetraacetylethylenediamine, cyanamides, ultraviolet light, any combination thereof, or any mixture thereof. In addition to or in lieu of contacting the lignocellulose substrates with an oxidant and/or catalyst, ultrasonic waves, photo-Fenton and/or electro-Fenton reactions (in situ generation of hydroxyl radicals by radiation or electric currents) can be used. In one or more embodiments, the catalyst can be or include one or more transition metals with coordinated Lewis bases. Any catalyst or mixture of catalysts can be combined with the lignocellulose substrates and the oxidant to produce the mixture.
Suitable metal can include one or more Group 3 to Group 12 metal atoms. As used herein, all reference to the Periodic Table of the Elements and groups thereof is to the NEW NOTATION published in HAWLEY'S CONDENSED CHEMICAL DICTIONARY, Thirteenth Edition, John Wiley & Sons, Inc., (1997) (reproduced there with permission from IUPAC) unless otherwise noted. Illustrative transition metals can include, but are not limited to, metal ions of iron, copper, manganese, tungsten, molybdenum, cobalt, titanium, or any mixture thereof. The metal can be in the form of an oxide. The metal can be in the form of a salt or complex, e.g., bound to one or more complexing agents or compounds. Illustrative ions or complexing compounds can include, but are not limited to, cyanide (CN−), sulfate (SO42−), ethylenediaminetetraacetic acid (EDTA), ethylenediamine-N,N′-disuccinic acid (EDDS), ethyleneglycol bis(2-aminoethyl)-N,N,N′,N′-tetraacetic acid (EGTA), diethylenetriaminepentaacetic acid (DTPA), trans-1,2-diaminocyclohexane tetraacetic acid (CDTA), iminodisuccinate (IDS), nitrilotriacetic acid (NTA), salts thereof, acids thereof, hydrates thereof, or any mixture thereof. Other complexing compounds can include phosphates, or complexing agents based on phosphonic acid, oxalic acid, ascorbic acid, nitrilo acetate, gallic acid, fulvic acid, polyoxomethalates, salts thereof, acids thereof, hydrates thereof.
The metal ions can include compounds or complexes containing iron ions (e.g., Fe2− or Fe3+), such as iron(II) sulfate, iron(II) oxide, iron(III) sulfate, iron(III) oxide. Other iron ion containing catalyst can include, but are not limited to, ferricyanide ([Fe(CN)6]3−), ferrocyanide ([Fe(CN)6]4−), and/or nitroprusside ([Fe(CN)5NO]2−). For example, the catalyst can be or include, but is not limited to, potassium ferricyanide (K3[Fe(CN)6]), potassium ferrocyanide (K4[Fe(CN)6]), ammonium ferricyanide hydrate ((NH4)3[Fe(CN)6].xH2O), ammonium ferrocyanide hydrate ((NH4)4[Fe(CN)6].xH2O), sodium ferricyanide decahydrate (Na3[Fe(CN)6].10H2O), sodium ferrocyanide decahydrate (Na4[Fe(CN)6].10H2O), sodium nitroprusside dihydrate (Na2[Fe(CN)5NO].2H2O). Other suitable catalyst that contain iron can include, but are not limited to, Fe[EDTA], Fe[EDDS], Fe[DTPA], Fe[EGTA], Fe[CDTA], Fe[IDS], or any mixture thereof. In at least one specific embodiment, the catalyst can include ferricyanide, e.g., potassium ferricyanide, a complex of iron (e.g., ferric and/or ferrous) and ethylenediaminetetraacetic acid (EDTA), a complex of iron (e.g., ferric and/or ferrous) and (S,S)-ethylenediamine-N,N′-disuccinic acid ((S,S)-EDDS), a complex of iron (e.g., ferric and/or ferrous) and (R,R)-ethylenediamine-N,N′-disuccinic acid ((R,R)-EDDS), a complex of iron (e.g., ferric and/or ferrous) and (R,S)-ethylenediamine-N,N′-disuccinic acid ((R,S)-EDDS), a complex of iron (e.g., ferric and/or ferrous) and diethylenetriaminepentaacetic acid (DTPA), a complex of iron (e.g., ferric and/or ferrous) and trans-1,2-diaminocyclohexane tetraacetic acid (CDTA), a complex of iron (e.g., ferric and/or ferrous) and iminodisuccinate (IDS), salts thereof, acids thereof, hydrates thereof, or any mixture thereof.
Tertiary amines can be represented by the general Formula NR1R2R3, where each R1, R2, and R3 is independently selected from alkyls, cycloalkyls, heterocycloalkyls, aryls, heteroaryls, and substituted aryls. The alkyl can include branched or unbranched alkyls having 1 carbon atom to about 15 carbon atoms or 1 carbon atom to about 8 carbon atoms. Illustrative alkyls can include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec butyl, t-butyl, n-pentyl, n-hexyl, ethylhexyl, isomers thereof, or any mixture thereof. The cycloalkyls can include 3 carbon atoms to about 7 carbon atoms. Illustrative cycloalkyls can include, but are not limited to, cyclopentyl, substituted cyclopentyl, cyclohexyl, and substituted cyclohexyl. The term “aryl” refers to an aromatic substituent containing a single aromatic ring or multiple aromatic rings that are fused together, linked covalently, or linked to a common group such as a methylene or ethylene moiety. More specific aryl groups contain one aromatic ring or two or three fused or linked aromatic rings, e.g., phenyl, naphthyl, biphenyl, anthracenyl, phenanthrenyl, and the like. The aryl substituents can generally include up to about 20 carbon atoms. The term “heteroatom-containing,” as in a “heteroatom-containing cycloalkyl group,” refers to a molecule or molecular fragment in which one or more carbon atoms is replaced with an atom other than carbon, e.g., nitrogen, oxygen, sulfur, phosphorus, boron, or silicon. Similarly, the term “heteroaryl” refers to an aryl substituent that is heteroatom-containing. The term “substituted,” as in “substituted aryls,” refers to a molecule or molecular fragment in which at least one hydrogen atom bound to a carbon atom is replaced with one or more substituents that are functional groups such as hydroxyl, alkoxy, alkylthio, phosphino, amino, halo, silyl, and the like. Illustrative tertiary amines can include, but are not limited to, trimethylamine, triethylamine, triethanolamine, any combination thereof, or any mixture thereof. Illustrative polymeric tertiary amines can include, but are not limited to, poly(N-methyl-diallyl amine), poly(N-dimethyl-vinyl amine), copolymers of N-dimethyl-vinyl amine, any combination thereof, or any mixture thereof. Illustrative polyamines can include, but are not limited to, diethylenetriamine (“DETA”), triethylenetetramine (“TETA”), tetraethylenepentamine (“TEPA”). Other polyamines can include, for example, 1,3-propanediamine, 1,4-butanediamine, polyamidoamines, and polyethylenimines.
Illustrative phosphates can be or include, but are not limited to, potassium, phosphate, sodium phosphate, ammonium phosphate, or any combination or mixture thereof. Illustrative bisulfites can include, but are not limited to, sodium bisulfite. Illustrative metabisulfites can be or include, but are not limited to, sodium metabisulfite, potassium metabisulfite, or any combination or mixture thereof. Illustrative cyanamides can include, but are not limited to, cyanamide, calcium cyanamide, sodium hydrogen cyanamide, any combination thereof, or any mixture thereof.
The amount of catalyst, if present in the free radical precursor, can widely vary. For example, the amount of catalyst in the mixture can be about 0.00001 wt %, about 0.0001 wt %, about 0.001 wt %, about 0.01 wt %, or about 0.1 wt % to about 0.5 wt %, about 1 wt %, about 3 wt %, about 5 wt %, about 10 wt %, or about 20 wt %, based on the dry weight of the lignocellulose substrates, with suitable ranges including the combination of any two values. In another example, the amount of catalyst in the mixture can be about 0.01 wt % to about 1.5 wt %, about 0.1 wt % to about 1.3 wt %, about 0.05 wt % to about 0.5 wt %, about 0.07 wt % to about 0.4 wt %, about 0.05 wt % to about 5 wt %, based on the dry weight of the lignocellulose substrates. In another example, the amount of the catalyst in the mixture can be about 0.001 wt % to about 0.5 wt %, about 0.15 wt % to about 0.35 wt %, about 0.1 wt % to about 0.4 wt %, about 0.1 wt % to about 2 wt %, about 0.05 wt % to about 3 wt %, about 0.05 wt % to about 0.35 wt %, about 0.1 wt % to about 4.5 wt %, about 0.15 wt % to about 4 wt %, about 0.05 wt % to about 3 wt %, or about 0.01 wt % to about 3.5 wt %, based on the dry weight of the lignocellulose substrates.
In one or more embodiments, the amount of the metal, if present in the catalyst, that can remain bound to the complexing agent until the mixture is heated, e.g., to a temperature of about 60° C. to about 300° C., can be at least at least 11%, at least 13%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, or at least 70% of the amount of metal that was initially present in the mixture and bound to the complexing agent. In another example, the amount of the metal, if present in the catalyst, that can remain bound to the complexing agent until the mixture is heated, e.g., to a temperature of about 60° C. to about 300° C., can be about 11% to about 95%, about 15% to about 85%, about 20% to about 90%, about 30% to about 80%, about 11% to about 100%, about 35% to about 75%, about 40% to about 70%, or about 30% to about 95% of the amount of the metal initially present in the mixture and bound to the complexing agent.
The catalyst, if combined with a liquid medium, can have a total concentration of solids of about 0.001 wt % to about 99.9 wt %. In one example, if the catalyst is combined with a liquid medium, the catalyst and liquid medium mixture can have a concentration of solids of about 0.1 wt %, about 0.5 wt %, about 1 wt %, or about 2 wt % to about 4 wt %, about 5 wt %, about 6 wt %, about 7 wt %, or about 8 wt %, based on the combined weight of the catalyst and the liquid medium, with suitable ranges including the combination of any two values.
The oxidant, if present in the free radical precursor, can be or include any suitable oxidant or combination of oxidants. The oxidant can be a solid, liquid, gas, or multi-phase. Illustrative oxidants can include, but are not limited to, inorganic and/or organic peroxy compounds, ozonides, halogen containing oxidants, any combination thereof, or any mixture thereof. Illustrative inorganic peroxy compounds can include, but are not limited to, hydrogen peroxide, hydrogen peroxide generating compounds, e.g., alkali metal salts of percarbonate, perborate, peroxysulfate, peroxyphosphate, and/or peroxysilicate, and/or corresponding weak acids. Illustrative organic peroxy compounds can include, but are not limited to, t-butyl peroxide, benzoyl peroxide, peroxy carboxylic acids, peracetic acid, perbenzoic acid, hydroperoxides, e.g., t-butyl hydroperoxides, or any combination or mixture thereof. Illustrative halogen containing oxidants can include, but are not limited to, alkali metal chlorite, alkali metal hypochlorite, chlorine dioxide, and/or a chloro sodium salt of cyanuric acid. An illustrative ozonide can include, but is not limited to, dimethyloxirane.
The oxidant can be combined with one or more liquid mediums. For example, the oxidant can be or include an aqueous solution of hydrogen peroxide. The concentration of oxidant, e.g., hydrogen peroxide, combined with a liquid medium, e.g., water, can be about 1 wt %, about 3 wt %, about 5 wt %, about 10 wt %, about 15 wt %, about 20 wt %, about 25 wt %, or about 30 wt % to about 50 wt %, about 60 wt %, about 70 wt %, about 80 wt %, about 90 wt %, or about 98 wt %, based on the combined weight of the oxidant and the liquid medium, with suitable ranges including the combination of any two values.
The amount of oxidant present in the mixture can depend, at least in part, on the particular oxidant, catalyst, lignocellulose substrates, and/or, if present, the polyphenolic material and, thus, can widely vary. For example, the amount of oxidant in the mixture can be about 1 wt % to about 200 wt %, based on the dry weight of the lignocellulose substrates. In another example, the amount of oxidant in the mixture can be about 1 wt %, about 5 wt %, about 10 wt %, or about 20 wt % to about 80 wt %, about 100 wt %, about 120 wt %, or about 150 wt %, based on the dry weight of the lignocellulose substrates, with suitable ranges including the combination of any two values. In another example, the oxidant can be present in the mixture in an amount of about 0.1 wt % to about 30 wt %, about 1 wt % to about 20 wt %, about 5 wt % to about 50 wt %, about 10 wt % to about 70 wt %, about 0.5 wt % to about 25 wt %, about 3 wt % to about 6 wt %, or about 2 wt % to about 8 wt %, based on the dry weight of the lignocellulose substrates. In still another example, the oxidant can be present in the mixture in amount of about 0.1 wt % to about 10 wt %, about 1 wt % to about 12 wt %, about 2 wt % to about 9 wt %, about 3 wt % to about 9 wt %, about 5 wt % to about 15 wt %, about 4 wt % to about 6 wt %, about 8 wt % to about 20 wt %, or about 2 wt % to about 10 wt %, based on the dry weight of the lignocellulose substrates.
In one or more embodiments, the amount of oxidant, if present as or in the free radical precursor, that can remain present until the mixture is heated, e.g., to a temperature of at least 60° C. to about 300° C., can be at least at least 11%, at least 13%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, or at least 70% of the amount of oxidant initially present in the mixture. In another example, the amount of the oxidant, if present in the free radical precursor, that can remain present until the mixture is heated, e.g., to a temperature of about 60° C. to about 300° C., can be about 11% to about 95%, about 15% to about 85%, about 20% to about 90%, about 30% to about 80%, about 11% to about 100%, about 35% to about 75%, about 40% to about 70%, or about 30% to about 95% of the amount of the oxidant initially present in the mixture.
As noted above, the polyphenolic material can be in a liquid form, a solid form or both. If the liquid form of the polyphenolic material includes a solid polyphenolic compound dissolved, suspended, dispersed or otherwise distributed within a liquid medium, any suitable liquid medium or combination of liquid mediums can be used. Illustrative liquid mediums can be or include, but are not limited to, water, alcohols, glycols, acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide, N-methylpyrrolidone, or any mixture thereof. Suitable alcohols can include, but are not limited to, methanol, ethanol, propanol, isopropanol, butanol, or any mixture thereof. Suitable glycols can include, but are not limited to, ethylene glycol, propylene glycol, or a mixture thereof. As used herein, the terms “aqueous medium” and “aqueous liquid” are used interchangeably and can be or include water and/or mixtures composed of water and/or other water-miscible solvents. Illustrative water-miscible solvents can include, but are not limited to, alcohols, ethers, amines, other polar aprotic solvents, and the like. As also noted above, the polyphenolic material can be water insoluble. The temperature of the polyphenolic compound, when in the liquid form, can widely vary. For example, the polyphenolic compound can be at a temperature of about 20° C., about 40° C., about 60° C., or about 80° C. to about 95° C., about 110° C., about 130° C., about 150° C. or more when in the liquid form. In one example, the polyphenolic compound can be at a temperature of about 25° C. when in the liquid form.
A polyphenolic material that includes a liquid medium can include about 0.1 wt %, about 1 wt %, about 3 wt %, about 5 wt %, about 10 wt %, about 20 wt %, about 30 wt %, about 40 wt %, about 43 wt %, or about 46 wt % to about 49 wt %, about 53 wt %, about 55 wt %, about 58 wt %, about 60 wt %, about 65 wt %, to about 70 wt %, about 80 wt %, about 90 wt %, about 95 wt % about 99 wt %, or about 99.9 wt % of polyphenolic material, based on the combined weight of the polyphenolic material and the liquid medium. For example, the polyphenolic material in the form of a liquid can include about 0.1 wt % to about 30 wt %, about 1 wt % to about 20 wt %, about 5 wt % to about 50 wt %, about 10 wt % to about 70 wt %, about 0.5 wt % to about 25 wt %, about 3 wt % to about 6 wt %, about 2 wt % to about 8 wt %, about 45 wt % to about 50 wt %, about 55 wt % to about 60 wt %, about 46 wt % to about 49 wt %, or about 56 wt % to about 59 wt % of the polyphenolic material, based on the combined weight of the polyphenolic material and the liquid medium. In another example, the polyphenolic material in the form of a liquid can include about 0.1 wt % to about 10 wt %, about 1 wt % to about 12 wt %, about 2 wt % to about 9 wt %, about 3 wt % to about 9 wt %, about 5 wt % to about 15 wt %, about 4 wt % to about 6 wt %, about 8 wt % to about 20 wt %, or about 2 wt % to about 10 wt % of the polyphenolic material, based on the combined weight of the polyphenolic material and the liquid medium.
In another example, a polyphenolic material in the form of a solution, e.g., an aqueous solution, can include about 0.1 wt % to about 30 wt %, about 1 wt % to about 20 wt %, about 5 wt % to about 50 wt %, about 10 wt % to about 70 wt %, about 0.5 wt % to about 25 wt %, about 3 wt % to about 6 wt %, about 2 wt % to about 8 wt %, about 45 wt % to about 50 wt %, about 55 wt % to about 60 wt %, about 46 wt % to about 49 wt %, or about 56 wt % to about 59 wt % of the polyphenolic material, based on the combined weight of the polyphenolic material and the liquid medium. In another example, the polyphenolic material in the form of a solution can include about 0.1 wt % to about 10 wt %, about 1 wt % to about 12 wt %, about 2 wt % to about 9 wt %, about 3 wt % to about 9 wt %, about 5 wt % to about 15 wt %, about 4 wt % to about 6 wt %, about 8 wt % to about 20 wt %, or about 2 wt % to about 10 wt % of the polyphenolic material, based on the combined weight of the polyphenolic material and the liquid medium.
As used herein, the solids concentration or solids content of a solution or solid/liquid mixture, e.g., polyphenolic material, as understood by those skilled in the art, can be measured by determining the weight loss upon heating a small sample, e.g., about 1 gram to about 5 grams of the mixture, to a suitable temperature, e.g., about 125° C., and a time sufficient to remove the liquid medium combined therewith. By measuring the weight of the sample before and after heating, the percent solids in the sample can be directly calculated or otherwise estimated.
Suitable solid polyphenolic materials can be in the form of a powder, flakes, granules, pellets, beads, particulates or other solid form. Polyphenolic materials in the form of a powder can have an average particle size of about 0.05 microns, about 0.1 micron, about 0.6 microns, about 1 micron, about 5 microns, about 7 microns or about 10 microns to about 115 microns, about 225 microns, about 350 microns, about 425 microns, about 500 microns, about 700 microns, about 850 microns, or about 1,000 microns. In another example, the polyphenolic material can have an average particle size of about 0.3 microns to about 160 microns, about 22 microns to about 48 microns, about 35 microns to about 60 microns, about 50 microns to about 75 microns or about 70 microns to about 120 microns about 30 microns to about 70 microns, about 60 microns to about 150 microns, about 100 microns to about 200 microns, about 175 microns to about 325 microns, about 220 microns to about 400 microns, or about 385 microns to about 500 microns.
The temperature of the polyphenolic compound, when in the solid form, can widely vary. For example, the polyphenolic compound can be at a temperature of about 20° C., about 40° C., about 60° C., or about 80° C. to about 95° C., about 110° C., about 130° C., about 150° C. or more when in the solid form. In one example, the polyphenolic compound can be at a temperature of about 25° C. when in the solid form.
A liquid polyphenolic material, e.g., an aqueous solution containing a polyphenolic compound, can be dried via any suitable process or combination of processes to produce a solid polyphenolic material. Illustrative processes for producing the particulate binder composition can include, but are not limited to, spray-drying, freeze drying, drum drying, pulse combustion drying, vacuum drying, precipitation, air drying, and/or dry spinning. For example, the liquid polyphenolic material can be spray-dried to provide a particulate or otherwise solid polyphenolic material.
The term “spray drying,” as used herein, refers to the process of producing a dry particulate solid product or particulate from a liquid mixture. The process can include spraying or atomizing the liquid polyphenolic material, e.g., forming small droplets, into a temperature controlled gas stream to evaporate the liquid from the atomized droplets and produce the particulate polyphenolic material. For example, in the spray drying process, the liquid polyphenolic material can be atomized to small droplets and mixed with a hot gas, e.g., air, to evaporate the liquid from the droplets. The temperature of the liquid mixture during the spray-drying process can usually be close to or greater than the boiling temperature of the liquid. An outlet air temperature of about 60° C. to about 120° C. can generally be used. The particle size and liquid, e.g., moisture, content of the spray dried particulate polyphenolic material can be adjusted, controlled, or otherwise influenced by one or more process variables, such as the gas feed rate, gas temperature, the feed rate of the liquid polyphenolic material, the temperature of the liquid polyphenolic material, the liquid droplet size, the solids concentration of the liquid polyphenolic material, or any combination thereof.
The particulate polyphenolic material, e.g., spray-dried polyphenolic material, can have a liquid, e.g., moisture, content of less than 20 wt %, less than 15 wt %, less than 10 wt %, less than 8 wt %, less than 6 wt %, less than 5 wt %, less than 4 wt %, less than 3 wt %, less than 2 wt %, or less than 1 wt %. For example, a polyphenolic material in the form of a solid particulate, e.g., a powdered polyphenolic material, can be free from any liquid medium, or can include about 0.1 wt % to about 5 wt %, about 0.5 wt % to about 8 wt %, about 1 wt % to about 10 wt %, about 3 wt % to about 6 wt %, about 2 wt % to about 12 wt %, about 5 wt % to about 15 wt %, about 3 wt % to about 9 wt %, or about 1 w % to about 14 wt % liquid medium.
If the polyphenolic material includes two or more polyphenolic materials, e.g., a solid polyphenolic material and a liquid polyphenolic material, or two solid polyphenolic materials, or two liquid polyphenolic materials, the two polyphenolic materials can be combined with the lignocellulose substrates and the free radical precursor in any order or sequence. For example, if the polyphenolic material includes a solid polyphenolic material and a liquid polyphenolic material, the liquid polyphenolic material can be combined with the lignocellulose substrates to produce a first partial mixture, the free radical precursor can be combined with the first partial mixture to produce a second partial mixture, and the solid polyphenolic material can be combined with the second partial mixture to produce the mixture. In another example, the solid polyphenolic material can be combined with the lignocellulose substrates to produce a first partial mixture, the free radical precursor can be combined with the first partial mixture to produce a second partial mixture, and the liquid polyphenolic material can be combined with the second partial mixture to produce the mixture. In another example, the liquid polyphenolic material and the solid polyphenolic material can be combined with one another to produce a first partial mixture, the first partial mixture can be combined with the lignocellulose substrates to produce a second partial mixture, and the free radical precursor can be combined with the second partial mixture to produce the mixture.
If the free radical precursor includes two or more components, e.g., a catalyst and an oxidant, and the polyphenolic material includes two or more components, e.g., a solid polyphenolic material and a liquid polyphenolic material, the plurality of lignocellulose substrates, catalyst, oxidant, solid polyphenolic material, and liquid polyphenolic material can be combined in any order or sequence with respect to one another. For example, the liquid polyphenolic material can be combined with the catalyst to produce a first partial mixture, the first partial mixture can be combined with the lignocellulose substrates to produce a second partial mixture, the oxidant can be combined with the second partial mixture to produce a third partial mixture, and the solid polyphenolic material can be combined with the third partial mixture to produce the mixture. In another example, the solid polyphenolic material can be combined with the catalyst to produce a first partial mixture, the first partial mixture can be combined with the lignocellulose substrates to produce a second partial mixture, the oxidant can be combined with the second partial mixture to produce a third partial mixture, and the liquid polyphenolic material can be combined with the third partial mixture to produce the mixture. In another example, the liquid polyphenolic material can be combined with the lignocellulose substrates to produce a first partial mixture, the first partial mixture can be combined with the catalyst to produce a second partial mixture, the oxidant can be combined with the second partial mixture to produce a third partial mixture, and the solid polyphenolic material can be combined with the third partial mixture to produce the mixture. In yet another example, the solid polyphenolic material can be combined with the lignocellulose substrates to produce a first partial mixture, the first partial mixture can be combined with the catalyst to produce a second partial mixture, the oxidant can be combined with the second partial mixture to produce a third partial mixture, and the liquid polyphenolic material can be combined with the third partial mixture to produce the mixture. In at least one embodiment, any two or more components of the mixture can be combined with one another simultaneously or substantially simultaneously.
If the polyphenolic material includes two or more polyphenolic materials, e.g., a solid polyphenolic material and a liquid polyphenolic material, or two solid polyphenolic materials, or two liquid polyphenolic materials, the amount of each polyphenolic material can widely vary. For example, a polyphenolic material that includes a first polyphenolic material and a second polyphenolic can include about 1 wt % to about 99 wt % of the first polyphenolic material and conversely about 99 wt % to about 1 wt % of the second polyphenolic material, based on the total weight of the polyphenolic material, e.g., the total weight of the first and second polyphenolic materials. In another example, the amount of the first polyphenolic material can be about 5 wt %, about 10 wt %, about 15 wt %, about 20 wt %, about 25 wt % about 30 wt %, about 35 wt %, about 40 wt %, or about 45 wt % to about 60 wt %, about 65 wt %, about 70 wt %, about 75 wt %, about 80 wt %, about 85 wt %, about 90 wt %, or about 95 wt %, based on the total weight of the first and second polyphenolic materials.
Lignin is a polymeric substance that can include substituted aromatics found in plant and vegetable matter associated with cellulose and other plant constituents. Illustrative plant and vegetable matter can include, but is not limited to, straw, hemp, sisal, cotton stalk, wheat, bamboo, sabai grass, rice straw, banana leaves, paper mulberry (e.g., bast fiber), abaca leaves, pineapple leaves, esparto grass leaves, fibers from the genus Hesperaloe in the family Agavaceae jute, salt water reeds, palm fronds, flax, ground nut shells, hardwoods, softwoods, recycled fiberboards such as high density fiberboard, medium density fiberboard, low density fiberboard, oriented strand board, particleboard, or any combination thereof. For example, the plant matter can be or include wood, for example hardwoods, softwoods, or a combination thereof. Illustrative types of wood can include, but are not limited to, alder, ash, aspen, basswood, beech, birch, cedar, cherry, cottonwood, cypress, elm, fir, e.g., Douglas fir, gum, hackberry, hickory, maple, oak, pecan, pine, e.g., Spruce pine, poplar, redwood, sassafras, spruce, sycamore, walnut, and willow.
Suitable lignin material can include, but is not limited to, lignin in its native or natural state, e.g., non-modified or unaltered lignin, lignosulfonates, or any combination or mixture thereof. In at least one example, the lignin can be or include kraft lignin. In at least one other example, the lignin can be or include lignosulfonates. Suitable lignosulfonates can include, but are not limited to, ammonium lignosulfonate, sodium lignosulfonate, calcium lignosulfonate, magnesium lignosulfonate, or any combination or mixture thereof. The lignin can be insoluble in water at a temperature of about 25° C. and having a pH of about 7, soluble in water at a temperature of about 25° C. and having a pH of about 7, or the lignin can include a mixture of water insoluble lignin and water soluble lignin. For example, kraft lignin can be insoluble in water at a temperature of about 25° C. and having a pH of about 7. In another example, ammonium lignosulfonate can be soluble in water at a temperature of about 25° C. and having a pH of about 7.
The lignin can be extracted, separated, or otherwise recovered from the wood, plant, and/or vegetable matter using any of a number of well established processes. For example, in the pulp and paper industry, lignin-containing materials such as wood, straw, corn stalks, bagasse, and other vegetable and plant tissues can be processed to recover the cellulose or pulp via the well known kraft or sulfate process or the well known sulfite process. The residual pulping liquors that include the lignin as a byproduct can be a source of lignin. The pulping liquors can also be referred to as black liquors. The chemical structure of lignin can vary and the variation can depend, at least in part, on the particular plant from which the lignin is recovered from, location the plant was grown, and/or on the particular method used in recovery or isolation of the lignin from the plant and/or vegetable matter. The lignin can include active groups, such as active hydrogens and/or phenolic hydroxyl groups through which crosslinking or bridging can be effected.
In one or more embodiments, the lignin can be separated from the black liquor using any suitable process or combination of processes. In one example, the black liquor can be acidified by mixing, blending, combining, or otherwise contacting the black liquor with one or more acids. The acid can be in the form of a solid, a liquid, a gas, or any combination thereof. Illustrative acids can include, but are not limited to, sulfur dioxide, organic acids, hydrochloric acid, nitric acid, carbon dioxide, sulfuric acid, or any mixture thereof. For example, carbon dioxide gas can be passed through the black liquor. Acidifying the black liquor can cause the lignin therein to precipitate and become suspended to form a first suspension, slurry, or other dispersion. The black liquor can be acidified to a pH of about 10 or less, e.g., a pH of about 9 to about 10.5.
The first suspension can be dewatered to provide a first lignin-rich or “first solids” product and a first lignin-lean or “first liquid” product. Illustrative dewatering processes can include, but are not limited to centrifugation, filtering, filter pressing, band filtering, rotary filtering, sedimentation, froth floatation, or any combination thereof. In at least one example, the solid-liquid mixture, e.g., suspension, can be dewatered with a filter press. The first lignin-rich product can be further dried by blowing or otherwise passing one or more gases, e.g., flue gas, air, vapor, heated air, or the like, which can remove additional liquid to provide a dried first lignin-rich product.
The first lignin-rich product or the dried first lignin-rich product can be suspended in a liquid medium to provide a second lignin suspension. During suspension of the first lignin-rich product a pH of the suspension can be adjusted, maintained, or otherwise controlled to maintain the pH of the suspension on the acidic side to provide the second lignin suspension. The pH of the second lignin suspension can be adjusted to a pH level of an acidified wash water contacted with a dried second lignin-rich product. The second lignin suspension can be separated to provide the second lignin-rich product and a second lignin-lean product. The acidified wash water can passed through or otherwise contact the second lignin-rich product. The acidified wash water can perform a displacement washing of the second lignin-rich product to provide a washed second lignin-rich product. The displacement washing can be carried out at substantially constant conditions without any dramatic gradient in the pH. The washed second lignin-rich product can be dried to provide a dried second lignin-rich product. The washed second lignin-rich product and/or the dried second-lignin rich product can be used as at least a portion of the polyphenolic material combined with the plurality of lignocellulose substrates and the free radical precursor to provide the mixture. Suitable processes for recovering the washed second lignin-rich product and/or the dried second-lignin rich product from the black liquor can include those discussed and described in U.S. Pat. Nos. 8,172,981 and 8,486,224.
In another example, the black liquor can be carbonated by mixing, blending, combining, bubbling, passing through, or otherwise contacting the black liquor with carbon dioxide to provide a carbonated black liquor. Carbonation of the black liquor can neutralize at least a portion of any sodium hydroxide and other basic components contained in the black liquor. The carbonated black liquor can be separated to provide a first lignin-rich product and a first lignin-lean liquid. The first lignin-rich product can be acidified to neutralize at least a portion of any residual sodium hydroxide and other basic components contained therein to provide an acidified lignin product. The acid used to acidify the first lignin-rich product can include, but is not limited to, sulfuric acid, hydrochloric acid, or a mixture thereof. Lignin can be recovered from the acidified lignin product to provide a recovered lignin. If desired, the recovered lignin can be washed to remove at least a portion of any residual acid and ash content to provide a purified lignin. In one or more embodiments, one or more oxidizing agents can be reacted with the black liquor prior to carbonation, the carbonated black liquor, and/or the first lignin-rich product. The oxidizing agent can reduce, substantially reduce, or eliminate an odor of the purified lignin and/or the purified lignin product. The purified lignin can be at further dried to provide a purified lignin product. The lignin, the purified lignin, and/or the purified lignin product can be combined with the plurality of lignocellulose substrates and the free radical precursor to provide the mixture. Suitable processes for recovering the lignin, the purified lignin, and/or the purified lignin from the black liquor can include those discussed and described in U.S. Patent Application Publication No. 2011/0294991.
In another example, a process for recovering lignin from black liquor can include the process commonly referred to as the organosolv process. The organosolve process uses an organic solvent to solubilize lignin and hemicelluloses. The organosolve process can include contacting lignocellulose material, e.g., wood chips or particles, with an aqueous organic solvent at a temperature of about 130° C., about 140° C., or about 150° C. to about 200° C., about 220° C., or about 230° C. The lignin can break down by hydrolytic cleavage of alpha aryl-ether links into fragments that can be solubilized in the solvent system. Illustrative solvents can include, but are not limited to, acetone, methanol, ethanol, butanol, ethylene glycol, formic acid, acetic acid, any combination thereof, or any mixture thereof. The aqueous organic solvent can have a concentration of the solvent in water of about 30 wt %, about 40 wt % or about 50 wt % to about 70 wt %, about 80 wt %, or about 90 wt %.
Since the lignin separated from the plant can be chemically altered from that found in the plant, the term “lignin,” can also refer to lignin products obtained upon separation from the cellulose or recovered from the plant matter. For example, in a sulfite pulping process, the lignocellulose material can be digested with a bisulfite or sulfite resulting in the at least partial sulfonation of the lignin. As such, the lignin can optionally be subjected to further cleavage and/or other modifications such as alkaline treatment or reaction with other constituents to decrease the sulfonate or sulfur content and/or increase the active groups. For example, the lignin can be processed such that the lignin has a phenolic hydroxyl content of about 1.5 wt % to about 5 wt % and a sulfonate or sulfur content of less than 3 wt %.
In other methods of recovery or separation of lignin from wood, plant, or vegetable material, the lignin may not be sulfonated, but could be chemically altered somewhat in some other manner. For example, in residual pulping liquors obtained in sulfate or other alkaline pulping processes, the lignin can be present as an alkali metal salt dissolved in the alkaline, aqueous liquor and can generally include a sufficient phenolic hydroxyl content to require no further modification. However, the alkali or kraft lignin can be further reacted with other constituents to further increase the active groups. “Hydrolysis lignin” that can be recovered from the hydrolysis of lignocellulose materials in the manufacture of sugar, for example, can also be altered somewhat from that found in the plant. As such hydrolysis lignin can be further modified to solubilize the lignin as well as to increase the phenolic hydroxyl content. Also, the lignin products such as residual pulping liquor may be subjected to various treatments such as, for example, acid, alkaline or heat treatments or reacted with the other chemicals which may further alter somewhat the lignin constituents. In one or more embodiments, the recovery or separation of lignin from wood, plant, or vegetable material can be carried out without chemically altering the lignin. For example, the separation or recovery of the lignin can be free from any intentional sulfonation.
The residual pulping liquors or the lignin products produced in the separation or recovery of lignin from the plant matter can include lignin of various weight average molecular weights (MW) of about 300 to over 100,000. For example, the lignin can have a MW of about 500, about 1,000, about 5,000, about 10,000, about 15,000, or about 20,000 to about 30,000, about 45,000, about 55,000, about 70,000, about 80,000, about 85,000, about 90,000, or about 95,000, with suitable ranges including the combination of any two values In another example, the lignin can have a MW of about 300, about 500, about 800, about 900, about 1,000, or about 1,100 to about 1,300, about 1,500, about 1,900, about 2,300, about 2,500, about 2,700, about 3,000, about 3,300, about 3,500, about 3,700, about 4,000, about 4,300, about 4,500, about 4,700, or about 5,000, with suitable ranges including the combination of any two values. In another example, the lignin can have a MW of about 500 to about 30,000, about 500 to about 20,000, about 1,000 to about 15,000, about 800 to about 6,000, about 2,000 to about 12,000, about 400 to about 10,000, or about 600 to about 8,000. In another example, the MW of the lignin can be about 600 to about 4,500, about 350 to about 1,100, about 750 to about 2,500, about 950 to about 3,100, about 1,500 to about 3,400, about 1,800 to about 4,200, about 6,000 to about 6,800, about 9,500 to about 10,000, or about 1,900 to about 2,700.
In one or more embodiments, the lignin can be insoluble in water at a temperature of about 25° C. and having a pH of about 7. In one or more embodiments, the lignin can be substantially insoluble in water at a temperature of about 25° C. and having a pH of about 7. For example, a maximum amount of the lignin capable of dissolving in water at a temperature of about 25° C. and having a pH of about 7 can be 5 wt %, 4.5 wt %, about 4 wt %, 3.5 wt %, 3 wt %, 2.5 wt %, 2 wt %, 1.5 wt %, 1.3 wt %, 1 wt %, 0.9 wt %, 0.8 wt %, 0.7 wt %, 0.6 wt %, 0.5 wt %, 0.4 wt %, 0.3 wt %, 0.2 wt %, or 0.1 wt %, or less. In another example, the lignin can have a solubility in water at a temperature of about 25° C. and having a pH of about 7 of less than 5 wt %, less than 4 wt %, less than 3 wt %, 2.5 wt %, 2 wt %, 1.5 wt %, 1.3 wt %, 1 wt %, 0.9 wt %, 0.8 wt %, 0.7 wt %, 0.6 wt %, 0.5 wt %, 0.4 wt %, 0.3 wt %, 0.2 wt %, or 0.1 wt %, or less. In at least one example, the lignin that can be insoluble or substantially insoluble in water at a temperature of about 25° C. and having a pH of about 7 can be kraft lignin.
Depending on the particular lignin, the amount of sulfur contained in the lignin can widely vary. For example, the lignin an include about 1 wt %, about 1.5 wt %, about 2 wt %, about 2.5 wt %, or about 3 wt % to about 4 wt %, about 5 wt %, about 6 wt %, about 7 wt %, about 8 wt %, about 9 wt %, about 10 wt %, or more of sulfur. In another example, the lignin can contain less than 5 wt % sulfur, less than 4.5 wt % sulfur, less than 4 wt % sulfur, less than 3.5 wt % sulfur, less than 3 wt % sulfur, less than 2.7 wt % sulfur, less than 2.5 wt % sulfur, less than 2.3 wt % sulfur, less than 2 wt % sulfur, less than 1.7 wt % sulfur, or less than 1.5 wt % sulfur. In another example, the lignin can include about 6 wt % or more, about 6.5 wt % or more, about 7 wt % or more, or about 7.5 wt % or more to about 8 wt %, about 9 wt %, or about 10 wt % sulfur. In another example, the lignin can be kraft lignin and the kraft lignin can contain less than 5 wt % sulfur, less than 4.5 wt % sulfur, less than 4 wt % sulfur, less than 3.5 wt % sulfur, less than 3 wt % sulfur, less than 2.7 wt % sulfur, less than 2.5 wt % sulfur, less than 2.3 wt % sulfur, less than 2 wt % sulfur, less than 1.7 wt % sulfur, or less than 1.5 wt % sulfur. In another example, the lignin can be ammonium lignosulfonate and the ammonium lignosulfonate can include about 6 wt % or more, about 6.5 wt % or more, about 7 wt % or more, or about 7.5 wt % or more to about 8 wt %, about 9 wt %, or about 10 wt % sulfur.
The sulfur content of the lignin can be measured or calculated using elemental analysis techniques. For example, the sulfur content of the lignin can be indirectly determined or estimated using CHN analysis, which can be accomplished by combustion analysis. More particularly, a sample of the lignin can be burned in an excess of oxygen, and various traps can collect the combustion products—carbon dioxide, water, and nitric oxide. The masses of these combustion products can be used to calculate the composition of the unknown sample.
In one or more embodiments, a ratio of aromatic carbon atoms plus alkenic carbon atoms to aliphatic carbon atoms (aromatic carbon atoms+alkenic carbon atoms:aliphatic carbon atoms) in the lignin can be about 1:1, about 1.3:1, about 1.5:1, about 1.7:1, about 2:1, about 2.3:1, about 2.5:1, or about 2.7:1 to about 3.5:1, about 3.7:1, about 4:1, about 4.3:1, about 4.5:1, about 4.7:1, about 5:1, about 5.3:1, about 5.5:1, about 5.7:1, or about 6:1, based on quantitative analysis of 13C NMR spectra of the lignin. In one example, the lignin can have a ratio of aromatic carbon atoms plus alkenic carbon atoms to aliphatic carbon atoms of at least 2.5:1, at least 2.7:1, at least 3:1, at least 3.3:1, at least 3.5:1, at least 3.7:1, at least 4:1, at least 4.3:1, at least 4.5:1, at least 4.7:1, or at least 5:1 to about 5.3:1, about 5.5:1, about 5.7:1, or about 6:1, based on quantitative analysis of 13C NMR spectra of the lignin. In another example, the lignin can have a ratio of aromatic carbon atoms plus alkenic carbon atoms to aliphatic carbon atoms of about 1:1 to about 2:1, about 1.1:1 to about 1.9:1, about 1.2:1 to about 1.8:1, about 1.3:1 to about 1.7:1, about 1.4:1 to about 1.6:1, based on quantitative analysis of 13C NMR spectra of the lignin. In another example, the lignin can have a ratio of aromatic carbon atoms plus alkenic carbon atoms to aliphatic carbon atoms of about 1.5:1, about 2:1, about 2.5:1, about 3:1, about 3.5:1, about 4:1, about 4.5:1, or about 5:1, based on quantitative analysis of 13C NMR spectra of the lignin. In another example, the lignin can be kraft lignin and the kraft lignin can have a ratio of aromatic carbon atoms plus alkenic carbon atoms to aliphatic carbon atoms of about at least 2.5:1, at least 2.7:1, at least 3:1, at least 3.3:1, at least 3.5:1, at least 3.7:1, at least 4:1, at least 4.3:1, at least 4.5:1, at least 4.7:1, or at least 5:1 to about 5.3:1, about 5.5:1, about 5.7:1, or about 6:1, based on quantitative analysis of 13C NMR spectra of the kraft lignin. In another example, the lignin can be an ammonium lignosulfonate and the ammonium lignosulfonate can have a ratio of aromatic carbon atoms plus alkenic carbon atoms to aliphatic carbon atoms of about 1:1 to about 2:1, about 1.1:1 to about 1.9:1, about 1.2:1 to about 1.8:1, about 1.3:1 to about 1.7:1, about 1.4:1 to about 1.6:1, based on quantitative analysis of 13C NMR spectra of the ammonium lignosulfonate.
The liquors from which the lignin can be recovered can also include one or more other constituents in addition to the lignin. For example, in the sulfite pulping process, the spent sulfite liquor can include lignosulfonates that can be present as salts of cations, such as magnesium, calcium, ammonium, sodium and/or other cations. The spent sulfite liquor solids can include about 40 wt % to about 65 wt % lignosulfonates with the remainder being carbohydrates and other organic and inorganic constituents dissolved in the liquor. Lignin products produced by other pulping processes can also include other materials such as carbohydrates, degradation products of carbohydrates, and resinous materials which are separated from the cellulosic materials with the lignin. It should be noted that it is not necessary to separate the lignin from the other constituents that can be present. It should also be noted that at least a portion of any other constituents, if present, can be separated from the lignin.
Suitable processes for isolating or otherwise separating lignin or lignin containing products from wood, plant, vegetable, or other lignin containing matter can include those discussed and described in U.S. Pat. Nos. 1,856,567; 2,525,433; 2,680,113; 2,690,973; 3,094,515; 3,158,520; 3,503,762; 3,585,104; 3,726,850; 3,769,272; 3,841,887; 4,100,016; 4,131,564; 4,184,845; 4,308,203; 4,355,996; 4,470,876; 4,740,591; 4,764,596; 8,172,981; 8,486,224; and 8,053,566; U.S. Patent Application Publication Nos.: 2011/0297340; 2011/0294991; and 2012/0022240; and WO Publication Nos.: WO1992/018557A1, WO1993/021260A2; WO1994/024192A1; WO2005/062800A2; WO2006/031 175 A1; and WO2011/150508.
Commercially available lignin can include, but is not limited to, lignin products available from Tembec (Canada), Borregaard, and Mead-Westvaco. For example, a suitable powdered ammonium lignosulfonate can include ARBO® A02P and a suitable liquid ammonium lignosulfonate can include ARBO® A02L, both available from Tembec.
The novolac resin can be produced by reacting a phenolic component or compound with an aldehyde component or aldehyde compound(s) in the presence of an acid catalyst. The phenolic component of the novolac resin can include a variety of substituted phenolic compounds, unsubstituted phenolic compounds, or any combination of substituted and/or unsubstituted phenolic compounds. For example, the phenolic component can be mono-hydroxy benzene (phenol). Examples of substituted phenolic components can include, but are not limited to, alkyl-substituted phenols, such as the cresols and xylenols; cycloalkyl-substituted phenols, such as cyclohexyl phenol; alkenyl-substituted phenols; aryl-substituted phenols, such as p-phenyl phenol; alkoxy-substituted phenols, such as 3,5-dimethyoxyphenol; aryloxy phenols, such as p-phenoxy phenol; halogen-substituted phenols, such as p-chlorophenol, isomers thereof, or derivatives thereof. Specific examples of suitable phenolic component or compound used in preparing and incorporated in a novolac resin can include, but are not limited to, bisphenol A, bisphenol F, catechol, resorcinol, hydroquinone, o-cresol, m-cresol, p-cresol, 2,6-xylenol, 2,5-xylenol, 2,4-xylenol, 2,3-xylenol, 3,5-xylenol, 3,4-xylenol, 3,4,5-trimethylphenol, 3-ethyl phenol, 3,5-diethyl phenol, p-butyl phenol, 3,5-dibutyl phenol, p-amyl phenol, p-cyclohexyl phenol, p-octyl phenol, 3,5-dicyclohexyl phenol, p-phenyl phenol, p-phenol, 3,5-dimethoxy phenol, 3,4,5-trimethoxy phenol, p-ethoxy phenol, p-butoxy phenol, 3-methyl-4-methoxy phenol, p-phenoxy phenol, naphthol, anthranol, substituted derivatives thereof, isomers thereof, or any mixture thereof. In one example, about 80 wt % or greater, about 90 wt % or greater, or about 95 wt % or greater of the phenolic component includes phenol (mono-hydroxy benzene).
Illustrative aldehyde compounds can include the so-called masked aldehydes or aldehyde equivalents, such as acetals or hemiacetals. Suitable aldehydes can be represented by the general Formula R—CHO, where R is a hydrogen or a hydrocarbon radical generally having 1 carbon atom to about 8 carbon atoms. Specific examples of suitable aldehyde compounds can include, but are not limited to, formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, furfuraldehyde, benzaldehyde, any combination thereof, or any mixture thereof. As used herein, the term “formaldehyde” can refer to formaldehyde, formaldehyde derivatives, other aldehydes, or combinations thereof. In one example, the aldehyde component can be formaldehyde. One or more difunctional aldehydes can also be used to produce the novolac resin, and could advantageously be used to introduce cross-links ultimately into the at least partially cured novolac resin.
The aldehyde can be used in many forms such as solid, liquid, and/or gas. Considering formaldehyde in particular, the formaldehyde can be or include paraform (solid, polymerized formaldehyde), formalin solutions (aqueous solutions of formaldehyde, sometimes with methanol, in 37%, 44%, or 50% formaldehyde concentrations), urea-formaldehyde concentrate (“UFC”), and/or formaldehyde gas in lieu of or in addition to other forms of formaldehyde can also be used. In another example, the aldehyde can be or include a pre-reacted urea-formaldehyde mixture having a urea to formaldehyde weight ratio of about 1:2 to about 1:3.
A molar ratio of formaldehyde to phenol used to produce the novolac resin can be about 0.5 to about 0.95 or about 0.7 to about 0.85. The reaction between the phenol and the formaldehyde to produce the novolac resin can be carried out in the presence of an acid catalyst under acidic conditions. Suitable acid catalysts can include, but are not limited to, oxalic acid, sulfuric acid, p-toluene sulfuric acid, hydrochloric acid, salicylic acid, mineral acids and salts thereof, any combination thereof, or any mixture thereof. Mixed catalyst systems, such as ZnOAc/oxalic acid and other divalent metal compounds, e.g., acetates, can be used to prepare “high-ortho” novolac resins. Divalent metal compounds can include calcium, magnesium, zinc, cadmium, lead, copper, cobalt, and nickel. In at least one example, the catalyst can include oxalic acid, sulfuric acid, p-toluene sulfonic acid, and ZnOAc/oxalic acid. In another example, the catalyst can be oxalic acid or ZnOAc/oxalic acid.
The amount of acid catalyst used to produce the novolac resin can be sufficient to catalyze the reaction between the phenol and formaldehyde to produce the novolac resin. The phenol/formaldehyde reaction can be conducted in about 1 hour to about 6 hours, e.g., in about 2 hours to about 4 hours. The phenol/formaldehyde reaction can be carried out at a temperature of about 80° C. to about 100° C., e.g., about 95° C. to about 100° C. The reaction can be carried out at atmospheric pressure, although increased pressure can be utilized to permit the application of higher temperatures and, therefore, faster reaction rates and accordingly shorter reaction times.
The novolac resin can be treated to remove water and/or other volatile organic materials by heating, such as by distillation. After this treatment, the free phenol can be about 0.001% to about 2.0%, about 0.001% to about 0.5%. Distillation of the resulting novolac resin can be performed at atmospheric pressure by heating up to about 140° C., and then under a vacuum until the resin reaches a temperature of about 180° C. to about 220° C. Other suitable methods for treating the resin via heat can include thin-film evaporators. The resulting molten novolac resin can be cooled to a temperature below about 100° C.
If desired, the novolac resin can be neutralized. Neutralization of the novolac resin can be accomplished by the addition of one or more bases or base compounds, such as sodium hydroxide and/or potassium hydroxide, or its equivalent. The base compound can be added in an amount sufficient to raise the pH of the novolac resin to between about 5 to about 9, e.g., about 6 to about 8. Typically, about 10 wt % to about 30 wt % of water, based on the total resin solids, can be added. Suitable novolac resins and inverted novolac resins can be as discussed and described in U.S. Pat. No. 5,670,571 and U.S. Patent Application Publication No. 2008/0280787.
As used herein, the term “tannin” refers to both hydrolyzable tannins and condensed tannins. As such, the polyphenolic compound can be or include hydrolyzable tannins, condensed tannins, or a combination of hydrolyzable tannins and condensed tannins. Illustrative genera of shrubs and/or trees from which suitable tannins can be derived can include, but are not limited to, Acacia, Castanea, Vachellia, Senegalia, Terminalia, Phyllanthus, Caesalpinia, Quercus, Schinopsis, Tsuga, Rhus, Juglans, Carya, and Pinus, any combination thereof, or any mixture thereof. In another example, genera from which suitable tannins can be derived can include, but are not limited to, Schinopsis, Acacia, or a combination thereof. In another example, genera from which suitable tannins can be derived can include, but are not limited to, Pinus, Carya, or a combination thereof.
Hydrolyzable tannins are mixtures of simple phenols such as pyrogallol and ellagic acid and of esters of a sugar, e.g., glucose, with gallic and digallic acids. Illustrative hydrolyzable tannins can include, but are not limited to, extracts recovered from Castanea sativa, (e.g., chestnut), Terminalia and Phyllantus (e.g., myrabalans tree species), Caesalpinia coriaria (e.g., divi-divi), Caesalpinia spinosa, (e.g., tara), algarobilla, valonea, and Quercus (e.g., oak). Condensed tannins are polymers formed by the condensation of flavans. Condensed tannins can be linear or branched molecules. Illustrative condensed tannins can include, but are not limited to Acacia mearnsii (e.g., wattle or mimosa bark extract), Schinopsis (e.g., quebracho wood extract), Tsuga (e.g., hemlock bark extract), Rhus (e.g., sumach extract), Juglans (e.g., walnut), Carya illinoinensis (e.g., pecan), and Pinus (e.g., Radiata pine, Maritime pine, bark extract species).
The condensed tannins typically include about 70 wt % to about 80 wt % active phenolic ingredients (the “tannin fraction”) and the remaining ingredients (the “non-tannin fraction”) typically include, but are not limited to, carbohydrates, hydrocolloid gums, and amino and/or imino acid fractions. The condensed tannins can be used as recovered or extracted from the organic matter or the condensed tannins can be purified, e.g., about 95 wt % or more active phenolic ingredients. Hydrolyzable tannins and condensed tannins can be extracted from the starting material, e.g., trees and/or shrubs, using well established processes. A more detailed discussion of tannins is discussed and described in the Handbook of Adhesive Technology, Second Edition, CRC Press, 2003, chapter 27, “Natural Phenolic Adhesives I: Tannin,” and in Monomers, Polymers and Composites from Renewable Resources, Elsevier, 2008, chapter 8, “Tannins: Major Sources, Properties and Applications.”
The condensed tannins can be classified or grouped into one of two main categories, namely, those containing a resorcinol unit and those containing a phloroglucinol unit. Illustrative tannins that include the resorcinol unit include, but are not limited to, black wattle tannins and quebracho tannins. The resorcinol unit can be represented by Formula I below.




The resorcinol group is shown within the box overlaying the unit structure of black wattle and quebracho tannins in Formula II below. For simplicity, the structure of black wattle and quebracho tannins is represented by their flavonoid unit structure.




Illustrative tannins that include the phloroglucinol unit include, but are not limited to, pecan tannins and pine tannins. The phloroglucinol unit can be represented by Formula III below.




The phloroglucinol unit is shown within the box overlaying the unit structure of pecan and pine tannins in Formula IV below. For simplicity, the structure of pecan and pine tannins is represented by their flavonoid unit structure.




Phloroglucinol is known for higher reactivity than resorcinol. As such, tannins that include the phloroglucinol unit are more reactive than tannins that include the resorcinol unit.
The tannins can have an acidic pH. For example, the pH of the tannins can be about 3, about 3.5, or about 4 to about 5, about 5.5, about 6, or about 6.5, with suitable ranges including the combination of any two values. The tannins can have resorcinol and/or phloroglucinol functional groups. Suitable, commercially available tannins can include, but are not limited to, black wattle tannin, quebracho tannin, hemlock tannin, sumach tannins, pecan tannin, mimosa tannin, pine tannins, any combination thereof, or any mixture thereof.
Illustrative modified phenol formaldehyde resins can include ARYLZENE®, which can be represented by the general Formula V:




Other illustrative modified phenol formaldehyde resins can be or include those discussed and described in U.S. Pat. Nos. 5,674,970; 5,739,259; 5,756,642; 5,756,655; 5,770,750; 5,773,552; 5,837,798; 5,889,137; 6,166,151; 6,291,077; 6,399,740; and 6,569,953.
Humic acid can be represented by the general Formula VI:




where R can be hydrogen or any organic or other chemical group.
Any one or more of the polyphenolic compounds can be modified with one or more compounds having one or more carbon-carbon double bonds and one or more reactive functional groups. For example, the mixture can include one or more modified compounds having at least two hydrogen atoms that are abstractable in the presence of hydroxyl radicals produced by at least partially reacting one or more unsaturated monomers having one or more reactive functional groups with the one or more compounds having at least two hydrogen atoms that are abstractable in the presence of hydroxyl radicals, e.g., the lignin, tannin, novolac resin, modified phenol formaldehyde resin, bisphenol A, humic acid, salts thereof, acids thereof, and/or hydrates thereof. Any suitable compounds having one or more carbon-carbon double bonds and one or more reactive functional groups or combination of compounds having one or more carbon-carbon double bonds and one or more reactive functional groups can be used to produce the modified compound having at least two hydrogen atoms that are abstractable in the presence of hydroxyl radicals. The compounds having one or more carbon-carbon double bonds and one or more reactive functional groups can be nonionic. Illustrative compounds having one or more carbon-carbon double bonds and one or more reactive functional groups can include, but are not limited to, one or more unsaturated glycidyl ethers, one or more unsaturated glycidyl esters, one or more unsaturated mono-epoxides, one or more unsaturated methylol compounds, maleic anhydride, any combination thereof, or any mixture thereof.
Illustrative unsaturated glycidyl ethers can be represented by general Formula VII:




where R4 can be an ethylenically unsaturated radical such as vinyl, allyl, alkenyl, and the like. Suitable glycidyl ethers can include, but are not limited to, vinyl glycidyl ether, isopropenyl glycidyl ether, oleyl glycidyl ether, allyl glycidyl ether, p-vinylbenzyl glycidyl ether, o-allyl phenyl glycidyl ether, butenyl glycidyl ether, 4-vinylcyclohexyl glycidyl ether, abietylglycidyl ether, cyclohexeneylmethyl glycidyl ether, methallyl glycidyl ether, any combination thereof, or any mixture thereof.
Illustrative unsaturated glycidyl esters can be represented by general Formula VIII:




where R5 can be an unsaturated, unsubstituted alkyl radical having from two to 19 carbon atoms. Suitable glycidyl esters can include, but are not limited to, glycidyl methacrylate, glycidyl acrylate, glycidyl crotonate, glycidyl oleate, di-glycidyl maleate, di-glycidyl fumarate, any combination thereof, or any mixture thereof.
Illustrative unsaturated mono-epoxides can include, but are not limited to, linear or cycloaliphatic epoxy compounds, where the unsaturation is terminal. Suitable unsaturated mono-epoxides can be represented by general Formulas IXa and IXb:




where R6 can be an alkylene, an alkanediyl, or an alkanetriyl, optionally containing alkyl pendant groups; R7, R8, and R9 can independently be hydrogen, alkyl straight, branched, or cyclic, or any two of R6, R7, R8, or R9 can be alkylene, alkanediyl, or alkanetriyl, and/or combined to form a cyclic ring of 4 carbon atoms to about 12 carbon atoms, optionally containing alkyl pendants; and the number of carbon atoms in R6, R7, R8, and R9 can be such that the total number of carbon atoms in the epoxide can be 4 to about 50. In some embodiments, R6 and R8, R6 and R9, R7 and R8, or R7 and R9 can form a cyclic ring of 4 carbon atoms to about 12 carbon atoms, such as, for example, cyclopentene, cyclohexene, cycloheptene, or cyclooctene. Suitable unsaturated mono-epoxides can include, but are not limited to, 4-vinyl cyclohexene oxide, 1-methyl-4-isopropenyl cyclohexene oxide, butadiene monoxide, any combination thereof, or any mixture thereof.
Illustrative unsaturated methylol compounds can be represented by the general Formula X:




where R10, R11, R12, and R13 can independently be hydrogen or a hydrocarbyl group, e.g., an alkyl group, containing 1 carbon atom to about 6 carbon atoms. For example, an alkyl group can include from 1 carbon atom to 4 carbon atoms. In at least one example, R10, R11, R12, and R13 can each independently be methyl or hydrogen. Suitable unsaturated methylol compounds can include, but are not limited to, N-methylol acrylamide, N-methylol methacrylamide, N-methylol crotonamide, any combination thereof, or any mixture thereof. The N-methylol ethylenically unsaturated amide can be in the form of an aqueous solution.
In at least one example, the modified polyphenolic compound can be free or essentially free of any anionic monomers. For example, the modified polyphenolic compound can contain less than 3 wt %, less than 2.5 wt %, less than 2 wt %, less than 1.5 wt %, less than 1 wt %, less than 0.7 wt %, less than 0.5 wt %, less than 0.3 wt %, less than 0.1 wt %, less than 0.05 wt %, or less than 0.01 wt % anionic monomers. In at least one example, the modified polyphenolic compound can be free or essentially free of any ionic monomers. For example, the modified polyphenolic compound can contain less than 3 wt %, less than 2.5 wt %, less than 2 wt %, less than 1.5 wt %, less than 1 wt %, less than 0.7 wt %, less than 0.5 wt %, less than 0.3 wt %, less than 0.1 wt %, less than 0.05 wt %, or less than 0.01 wt % ionic monomers. In at least one other example the modified polyphenolic compound can be free or essentially free of any anionic and ionic monomers. For example, the modified polyphenolic compound can contain less than 3 wt %, less than 2.5 wt %, less than 2 wt %, less than 1.5 wt %, less than 1 wt %, less than 0.7 wt %, less than 0.5 wt %, less than 0.3 wt %, less than 0.1 wt %, less than 0.05 wt %, or less than 0.01 wt % anionic and ionic monomers. As used herein, the terms “essentially free of anionic monomers” and “essentially free of ionic monomers” means the modified polyphenolic compound does not include any intentionally added anionic monomers or ionic monomers, respectively. Said another way, the terms “essentially free of anionic monomers” and “essentially free of ionic monomers” means the modified polyphenolic compound may include anionic monomers and/or ionic monomers present as an impurity.
The amount of the polyphenolic compound in the mixture can widely vary. For example, the amount of the polyphenolic compound in the mixture can be about 0.01 wt % to about 50 wt %, based on the dry weight of the lignocellulose substrates. In another example, the amount of the polyphenolic compound in the mixture can be about 0.05 wt %, about 0.1 wt %, about 0.5 wt %, about 1 wt %, about 2 wt %, about 3 wt %, about 5 wt %, or about 7 wt % to about 15 wt %, about 20 wt %, about 25 wt %, or about 30 wt %, based on the dry weight of the lignocellulose substrates. In another example, the amount of the polyphenolic compound in the mixture can be about 0.1 wt %, about 0.5 wt %, about 1 wt %, about 3 wt %, or about 5 wt % to about 10 wt %, about 13 wt %, about 15 wt %, about 17 wt %, or about 20 wt %, based on the dry weight of the lignocellulose substrates. In another example, the amount of the polyphenolic compound in the mixture can be about 1 wt % to about 15 wt %, about 5 wt % to about 15 wt %, about 8 wt % to about 13 wt %, about 7 wt % to about 12 wt %, or about 5 wt % to about 25 wt %, based on the dry weight of the lignocellulose substrates.
In one or more embodiments, one or more unsaturated compounds having two or more unsaturated carbon-carbon bonds can optionally be combined with the lignocellulose substrates, the polyphenolic material, and the free radical precursor to produce the mixture. As used herein, the terms “unsaturated compound” and “reactive unsaturated compound” are used interchangeably and refer to compounds having two or more unsaturated carbon-carbon bonds, where at least one of the unsaturated carbon-carbon bonds is capable of free radical addition. As used herein, the phrase “capable of free radical addition” when used in conjunction with “unsaturated compound” means that the carbon-carbon double bond is a pi-bond (π-bond) that is not conjugated with an aromatic moiety and is capable of going through a free radical chain reaction mechanism. The free radical chain mechanism can include an initiation step, a propagation step, and a termination step. In one or more embodiments, the unsaturated carbon-carbon bond capable of free radical addition can be an alkene conjugated with a carbonyl group in an α,β-unsaturated carbonyl compound. The α,β-unsaturated carbonyl compound can include, but is not limited to, an aldehyde, a ketone, a carboxylic acid, an ester, an amide, an acyl halide, an acid anhydride, or an imide. For example, the α,β-unsaturated carbonyl compound can be, but is not limited to, an α,β-unsaturated aldehyde (e.g., an enal), an α,β-unsaturated ketone (e.g., an enone), an α,β-unsaturated carboxylic acid, an α,β-unsaturated ester, an α,β-unsaturated amide, an α,β-unsaturated acyl halide, an α,β-unsaturated acid anhydride, or an α,β-unsaturated imide. In one or more embodiments, the unsaturated compound can be substantially free or completely free from any aromatic moiety.
If the mixture includes the optional unsaturated compound, the amount of the unsaturated compound combined with the plurality of lignocellulose substrates, the polyphenolic material, and the free radical precursor can widely vary. For example, a weight ratio of the unsaturated compound to the free radical precursor in the mixture can be about 0.02:1, about 0.025:1, about 0.05:1, about 0.1:1, about 0.3:1, about 0.5:1, about 0.7:1, or about 1:1 to about 2:1, about 2.5:1, about 3:1, about 3.5:1, about 4:1, about 4.5:1, about 5:1, about 6:1, about 7:1, about 8:1, about 9:1, or about 10:1. In another example, the weight ratio of the unsaturated compound to the free radical precursor can be about 0.025:1 to about 10:1, about 0.1:1 to about 7.5:1, about 0.5:1 to about 5:1, about 0.3:1 to about 2.5:1, about 0.5:1 to about 1.5:1, about 3:1 to about 7:1, about 4:1 to about 6:1, about 6:1 to about 10:1, or about 0.3:1 to about 5.5:1. In another example, the weight ratio of the unsaturated compound to the free radical precursor can be at least 0.02:1, at least 0.025:1, at least 0.3:1, at least 0.35:1, at least 0.4:1, at least 0.45:1, at least 0.5:1, at least 0.6:1, at least 0.65:1, at least 0.7:1, at least 0.75:1, at least 0.8:1, at least 0.85:1, at least 0.9:1, at least 0.95:1, or at least 1:1 to about 3:1, about 4:1, about 5:1, about 6:1, about 7:1, about 8:1, about 9:1, or about 10:1. In yet another example, the weight ratio of the unsaturated compound to the free radical precursor can be about 0.125:1 to about 5:1, about 0.5:1 to about 3:1, about 1.5:1 to about 2.9:1, about 2:1 to about 4:1, or about 2.1:1 to about 4.5:1.
In one or more embodiments, an amount of the unsaturated compound in the mixture can be about 1 wt %, about 2 wt %, about 2.5 wt %, about 5 wt %, about 10 wt %, about 15 wt %, about 20 wt %, about 25 wt %, about 30 wt %, or about 35 wt % to about 60 wt %, about 65 wt %, about 70 wt %, about 75 wt %, about 80 wt %, about 85 wt %, about 90 wt %, about 95 wt %, about 97 wt %, about 98 wt %, about 99 wt %, or about 99.5 wt %, based on the combined weight of the unsaturated compound and the free radical precursor. For example, the amount of the unsaturated compound in the mixture can be about 10 wt % to about 85 wt %, about 30 wt % to about 83 wt %, about 25 wt % to about 65 wt %, about 40 wt % to about 85 wt %, about 35 wt % to about 75 wt %, about 20 wt % to about 40 wt %, about 30 wt % to about 50 wt %, about 40 wt % to about 60 wt %, about 50 wt % to about 70 wt %, or about 70 wt % to about 90 wt %, based on the combined weight of the unsaturated compound and the free radical precursor. In another example, the amount of the unsaturated compound in the mixture can be at least 3 wt %, at least 5 wt %, at least 10 wt %, at least 15 wt %, at least 20 wt %, at least 25 wt % at least 20 wt %, at least 35 wt %, at least 40 wt %, or at least 45 wt % to about 50 wt %, about 55 wt %, about 60 wt %, about 65 wt %, about 70 wt %, about 75 wt %, about 80 wt %, about 85 wt %, about 90 wt %, or about 95 wt %, based on the combined weight of the unsaturated compound and the free radical precursor. In another example, the amount of the unsaturated compound in the mixture can be less than 95 wt %, less than 90 wt %, less than 85 wt %, less than 80 wt %, less than 75 wt %, less than 70 wt %, less than 60 wt %, less than 55 wt %, less than 50 wt %, less than 45 wt %, or less 40 wt % and greater than 2 wt %, greater than 5 wt %, greater than 10 wt %, greater than 15 wt %, greater than 20 wt %, or greater than 25 wt %, based on the combined weight of the unsaturated compound and the free radical precursor.
In one or more embodiments, the unsaturated compound can include, but is not limited to, dicyclopentadiene (DCPD), 4-vinylcyclohexene, one or more vinyl ethers, one or more allyl ethers, diallyl phthalate, allyl crotonate, allyl cinamate, allyl methacrylate, vinyl methacrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, trimethylepropane triacrylate (TMPTA), poly(ethylene glycol) diacrylate, poly(ethylene glycol) dimethacrylate, trimethylolpropane triacrylate (TMPTA), pentaerythritol tetraacrylate, pentaerythritol triacrylate, polyacrylate, one or more conjugated dienes, one or more terpenes, one or more drying oils having an iodine number of about 115 or greater, one or more unsaturated prepolymers, one or more polyesters with one or more incorporated vinyl unsaturations, styrene-butadiene rubber (SBR), one or more starches having at least one unsaturated and polymerizable olefinic group, polymers derived from ring-opening polymerization of allyl caprolactone, a product or products formed by reacting one or more polyamidoamines and one or more unsaturated glycidyl ethers, or any mixture thereof.
In one or more embodiments, the unsaturated compound can have a double bond equivalent molecular weight of about 33, about 50, about 100, about 150, about 200, about 500, about 1,000, about 5,000, about 10,000, or about 15,000 to about 50,000, about 75,000, about 100,000, about 150,000, about 200,000, or about 250,000. In one or more embodiments, the unsaturated compound can have a double bond equivalent molecular weight of at least 33, at least 40, at least 45, at least 50, at least 75, at least 100, at least 200, at least 300, at least 400, at least 500, at least 1,000, at least 2,500, at least 5,000, at least 10,000, at least 20,000, at least 30,000, at least 40,000, at least 50,000, at least 60,000, at least 70,000, at least 80,000, at least 90,000, at least 100,000, at least 110,000, at least 120,000, at least 130,000, at least 140,000, or at least 150,000 to about 175,000, about 200,000, about 225,000, or about 250,000.
As used herein, the double bond equivalent molecular weight can be calculated by dividing the molecular weight of the unsaturated compound by the number of carbon-carbon double bonds the unsaturated compound contains. For example, if the unsaturated compound is cyclopentadiene, which has a molecular weight of 66.1 g/mol and two carbon-carbon double bonds, the double bond equivalent molecular weight is 33.05 (66.1 divided by 2). Accordingly, as used herein, the term “unsaturated compound” includes compounds that can be considered a monomer or discrete molecules. In another example, if the unsaturated compound is trimethylolpropane triacrylate (TMPTA), which has a molecular weight of 296.32 g/mol and 3 carbon-carbon double bonds, the double bond equivalent molecular weight 98.8.
In one or more embodiments, the unsaturated compound can have a weight average molecular weight (MW) of about 200, about 250, about 300, about 350, about 400, about 450, about 500, about 550, about 600, or about 650 to about 1,000, about 1,500, about 2,000, about 2,500, about 3,000, about 3,500, about 4,000, about 4,500, or about 5,000. For example, the unsaturated compound can have a weight average molecular weight of about 300 to about 3,000, about 330 to about 770, about 380 to about 930, about 470 to about 1,150, about 700 to about 1,800, about 800 to about 2,200, about 1,200 to about 2,000, about 400 to about 2,800, about 500 to about 2,700, about 600 to about 2,600, or about 700 to about 2,500. In one or more embodiments, the unsaturated compound can have a weight average molecular weight of at least 300, at least 325, at least 350, at least 375, at least 400, at least 425, at least 450, at least 475, at least 500, at least 525, at least 550, at least 575, at least 600, at least 625, at least 650, at least 675, at least 700, at least 750, at least 775, at least 800, at least 825, at least 850, at least 875, at least 900, at least 925, at least 950, at least 975, or at least 1,000.
Illustrative vinyl aromatic compounds can include, but are not limited to, 2-allylphenol, 4-allylphenol, and a mixture thereof. Illustrative vinyl ethers can include, but are not limited to, triethyleneglycol divinyl ether, divinyl ether, or a mixture thereof. Illustrative allyl ethers can include, but are not limited to, diallyl ether, trimethylolpropane diallyl ether, triallyl cyanurate, or any mixture thereof. Illustrative conjugated dienes can include, but are not limited to, 1,3-butadiene, 2,3-dimethylbutadiene, 2-methyl-1,3-butadiene(isoprene), 1,3-pentadiene(piperylene), cyclopentadiene, 2-chloro-1,3-butadiene(chloroprene), or any mixture thereof. Illustrative terpenes can include, but are not limited to, sesquiterpenes, or any mixture thereof. Illustrative sesquiterpenes can include, but are not limited to, farnesene, or any mixture thereof. Illustrative one or more drying oils having an iodine number of about 115 or greater can include, but are not limited to, linseed oil, soybean oil, sunflower oil, tung oil, grape seed oil, wheat germ oil, corn oil, or any mixture thereof. In some examples, the drying oil can have an iodine number of about 115 to about 180 or greater. Illustrative unsaturated prepolymers can include, but are not limited to, unsaturated polyester prepolymers, unsaturated polyether prepolymers, unsaturated polyamide prepolymers, unsaturated polyurethane prepolymers, or any mixture thereof. Illustrative polyesters with one or more incorporated vinyl unsaturations can include, but are not limited to, methacrylate, acrylate modified or terminated polyesters, or any mixture thereof.
As noted above, the α,β-unsaturated carbonyl compound can be, but is not limited to, an α,β-unsaturated aldehyde (e.g., an enal), an α,β-unsaturated ketone (e.g., an enone), an α,β-unsaturated carboxylic acid, an α,β-unsaturated ester, an α,β-unsaturated amide, an α,β-unsaturated acyl halide, an α,β-unsaturated acid anhydride, or an α,β-unsaturated imide. Illustrative α,β-unsaturated carbonyl aldehydes can include, but are not limited to, crotonaldehyde, 3-methylcrotonaldehyde, methacrolein, tiglic aldehyde, isomers thereof, or any mixture thereof. Illustrative α,β-unsaturated ketones can include, but are not limited to, methyl vinyl ketone, ethyl vinyl ketone, isomers thereof, or any mixture thereof. Illustrative α,β-unsaturated carboxylic acids can include, but are not limited to, maleic acid, itaconic acid, fumaric acid, glutaconic acid, citraconic acid, traumatic acid, muconic acid, aconitic acid, isomers thereof or any mixture thereof. Illustrative α,β-unsaturated esters can include, but are not limited to, esters of maleic acid, itaconic acid, fumaric acid, glutaconic acid, citraconic acid, traumatic acid, muconic acid, aconitic acid, isomers thereof, or any mixture thereof. An illustrative α,β-unsaturated amide can include, but is not limited to, acrylamide. Illustrative α,β-unsaturated acyl halides can include, but are not limited to, acryloyl chloride, methacryloyl chloride, crotonoyl chloride, fumaryl chloride, itaconyl chloride, sorbic chloride, isomers thereof, or any mixture thereof. An illustrative α,β-unsaturated acid anhydride can include, but is not limited to, maleic anhydride, an isomer thereof, or a mixture thereof. An illustrative α,β-unsaturated imide can include, but is not limited to, maleimide, an isomer thereof, or a mixture thereof.
Other compounds having one or more pi-bonds (e.g., unsaturated bonds) that is capable of going through a radical chain reaction mechanism, but is also conjugated with an aromatic moiety, can include, but are not limited to, vinyl aromatics, such as styrene, methylstyrenes, vinyl toluene, vinyl naphthalene, divinylbenzene (DVB), and vinylpyridine; methylstyrenes, such as α-methylstyrene and trans-β-methylstyrene; and any mixture thereof. Other illustrative vinyl aromatic compounds can include, but are not limited to, 2-allylphenol, 4-allylphenol, and a mixture thereof.
Illustrative unsaturated starch compounds having at least one unsaturated and polymerizable olefinic group can be represented by Formula XI below.




where R14 can be hydrogen or an alkyl group. Suitable starches can include, but are not limited to, maize or corn, waxy maize, high amylose maize, potato, tapioca, and wheat starch. Other starches such as genetically engineered starches can include high amylose potato and potato amylopectin starches. Suitable methods for preparing unsaturated starch compounds having at least one unsaturated and polymerizable olefinic group can include those discussed and described in U.S. Pat. No. 2,668,156.
The unsaturated prepolymer can include one or more monounsaturated prepolymers, one or more polyunsaturated prepolymers, or any mixture thereof. In one or more embodiments, suitable polyunsaturated prepolymers can include at least two sites of unsaturation, at least three sites of unsaturation, at least 4 sites of unsaturation, at least 5 sites of unsaturation, at least 6 sites of unsaturation, or more. In one or more embodiments, the unsaturated prepolymer can be unsaturated polyester prepolymers, unsaturated polyether prepolymers, unsaturated polyamide prepolymers, unsaturated polyurethane prepolymers, or any mixture thereof.
The unsaturated polyester prepolymer can be synthesized or produced by reacting one or more polyacids and one or more polyols with one another. For example, the unsaturated prepolymer can be produced via monoester formation. In another example, the unsaturated polyester prepolymer can be produced by reacting the polyacid and the polyol via a condensation reaction. As used herein, the term “polyacid” refers to compounds having at least two reactive acid groups per molecule. The acid functionality can be a carboxylic acid, a sulfonic acid, or a combination thereof. The term “polyacid” can also refer to acid anhydrides, e.g., maleic anhydride. The term “polyacid” can also refer to compounds containing at least one acid group per molecule and at least one acid anhydride group per molecule, e.g., a maleated fatty acid. As used herein, the term “polyol” refers to compounds that contain two or more hydroxyl functional groups.
In one or more embodiments, the one or more sites of unsaturation in the unsaturated polyester prepolymer can be directly introduced from the polyacid and/or the polyol, e.g., at least one of the polyacid and the polyol can include one or more sites of unsaturation. Said another way, the unsaturated polyester prepolymer can be produced by reacting one or more unsaturated polyacids with one or more saturated polyols, reacting one or more unsaturated polyols with one or more saturated polyacids, and/or by reacting one or more unsaturated polyacids with one or more unsaturated polyols. In one or more embodiments, the sites of unsaturation in the unsaturated polyester prepolymer can be appended to an initial prepolymer formed by reacting the polyacid and the polyol with one or more unsaturated compounds. In another example, the unsaturation sites of the unsaturated polyester prepolymer can be introduced via at least one of the polyol and the poly acid, and an additional unsaturated compound. Illustrative additional unsaturated compounds can include, but are not limited to, unsaturated alcohols, unsaturated acids, unsaturated epoxides, or any mixture thereof.
The polyacid and polyol components can be mixed, blended, or otherwise combined with one another to produce a reaction mixture. The polyacid and polyol can be reacted under conditions sufficient to substantially react the primary hydroxyl groups of the polyol with the polyacid, but insufficient to cause reaction of the secondary hydroxyl groups of the polyol with the polyacid to a substantial extent. As used herein, the phrase “substantially react the primary hydroxyl groups of the polyol with the polyacid” means that at least 90% of the primary hydroxyl groups of the polyol are reacted with the polyacid. As used herein, the phrase “insufficient to cause reaction of the secondary hydroxyl groups of the polyol with the polyacid to a substantial extent” means that less than 10% of the secondary hydroxyl groups of the polyol are reacted with the polyacid. For example, the polyacid and the polyol can be combined in a reaction vessel or container and heated to a temperature of about 50° C., about 60° C., about 70° C., or about 80° C. to about 110° C., about 125° C., about 140° C., or about 155° C. In another example, the polyacid and the polyol can be heated to a temperature of about 60° C. to about 130° C., about 80° C. to about 115° C., about 100° C. to about 150° C., or about 75° C. to about 135° C. The polyacid and the polyol can be reacted with one another for a time of about 10 minutes, about 30 minutes, about 1 hour, or about 2 hours to about 4 hours, about 6 hours, about 8 hours, or about 10 hours.
The progress of the reaction between the polyacid and the polyol can be monitored via any suitable method. One method for monitoring the extent of the reaction between the polyacid and the polyol can be through the use of infrared spectroscopy. For example, infrared spectroscopy can detect the presence of any unreacted polyacid. In one example, the reaction between the polyacid and the polyol can be carried out until the presence of the polyacid is no longer detected. It should be noted, however, that the unsaturated polyester prepolymer can include unreacted polyacid and/or unreacted polyol.
The polyacid and the polyol can be combined with one another in any desired ratio. For example, the polyol and the polyacid can be combined with one another at a molar ratio of about 1:5, about 1:4, or about 1:2, to about 1:1, about 2:1, about 4:1, or about 6:1. In at least one example, the amount of the polyacid combined with the polyol can be sufficient to provide a ratio of reactive acid and/or anhydride group(s) to hydroxyl groups of about 1:1 to about 2:1. In one or more embodiments, for each hydroxyl group present in the polyol about 1 acid group, about 2 acid groups, or about 3 acid groups can be present in the mixture of the polyol and the polyacid.
The polyacid can be or include, but is not limited to, one or more unsaturated and/or saturated aliphatic polyacids, one or more aromatic polyacids, one or more cycloaliphatic polyacids, one or more acid anhydrides, or any mixture thereof. Suitable unsaturated aliphatic diacids and saturated aliphatic diacids can include 2 carbon atoms to about 12 carbon atoms, 3 carbon atoms to about 10 carbon atoms, or 4 carbon atoms to about 8 carbon atoms. Illustrative unsaturated aliphatic diacids can include, but are not limited to, maleic acid, itaconic acid, fumaric acid, glutaconic acid, citraconic acid, traumatic acid, muconic acid, aconitic acid, or any mixture thereof. Illustrative saturated aliphatic diacids can include, but are not limited to, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, or any combination or mixture thereof. Illustrative aromatic diacids can include, but are not limited to, phthalic acid, isophthalic acid, terephthalic acid, or any combination or mixture thereof. Illustrative cyclo-aliphatic diacids can include, but are not limited to, cyclobutanedicarboxylic acid, cyclopentanedicarboxylic acid, cyclohexanedicarboxylic acid, isomers thereof, or any combination or mixture thereof. Illustrative acid anhydrides can include, but are not limited to, phthalic anhydride, mellitic anhydride, pyromellitic anhydride, maleic anhydride, or any combination or mixture thereof. In one or more embodiments, the polyacid can also include one or more unsaturated fatty acids reacted with any one or more of the polyacids discussed and described above. For example, in at least one specific embodiment, the polyacid can be or include the Alder-Ene reaction product between one or more unsaturated fatty acids and maleic anhydride. Therefore, for example, the polyacid can be or include one or more maleated fatty acids.
Illustrative saturated polyols can include, but are not limited to, ethylene glycol, polyglycerol, hyperbranched polyglycerol, diethylene glycol, triethylene glycol, polyethylene oxide (hydroxy terminated), glycerol, pentaerythritol, trimethylolpropane, diethanolamine, triethanolamine, ethyl diethanolamine, methyl diethanolamine, sorbitol, monosaccharides, such as glucose and fructose, disaccharides, such as sucrose, and higher polysaccharides such as starch and reduced and/or modified starches, dextrin, maltodextrin, polyvinyl alcohols, hydroxyethylcellulose, 1,4-cyclohexane diol, or any combination or mixture thereof. Illustrative unsaturated polyols can include, but are not limited to, 2-butene-1,4-diol, hydroxyl-terminated polybutadiene (HTPB) or any combination or mixture thereof.
Illustrative unsaturated alcohols suitable for introducing, appending, or otherwise providing one or more sites of unsaturation in the unsaturated polyester prepolymer can include, but are not limited to, any one or more of the unsaturated polyols discussed and described above, allylic alcohols, unsaturated alcohols obtained via metathesis reaction of hydroxyl-substituted unsaturated fatty acid or fatty acid esters, or any combination or mixture thereof. The preparation of unsaturated alcohols via metathesis reaction can be as discussed and described in U.S. Pat. No. 7,176,336. Illustrative unsaturated acids suitable for introducing, appending, or otherwise providing one or more sites of unsaturation in the unsaturated polyester prepolymer can include, but are not limited to, any one or more of the unsaturated polyacids discussed and described above, or any combination or mixture thereof. Suitable unsaturated epoxides suitable for introducing, appending, or otherwise providing one or more sites of unsaturation in the unsaturated polyester prepolymer can include, but are not limited to, allyl glycidyl ether, 3,4-epoxy-1-butene, 1,2-epoxy-5-hexene, any combination thereof or mixture thereof.
In one or more embodiments, one or more catalysts or unsaturated polyester prepolymer catalysts can optionally be present when the polyacid and the polyol are reacted with one another. Suitable catalysts can include, but are not limited to, monobutyltin oxide, dibutyltin oxide, dibutyltin dilaurate, or any mixture thereof. The one or more catalysts, if present, can be present in an amount of about 0.05 wt %, about 0.1 wt %, about 0.5 wt %, or about 1 wt % to about 2 wt %, about 3 wt %, about 4 wt %, or about 5 wt %, based on the combined weight of the polyacid and the polyol.
In one or more embodiments, the unsaturated polyester prepolymer can be combined with one or more reactive monomers in lieu of or in addition to the water. Illustrative reactive monomers that can be combined with the unsaturated polyester prepolymer can include, but are not limited to, styrene, methyl styrene, chlorostyrene, vinyl toluene, divinyl benzene, vinyl acetate, acrylic acid, methacrylic acid, lower alkyl esters of acrylic acid, lower alkyl esters of methacrylic acid, diallyl phthalate, vegetable oils, and drying oils, e.g., linseed oil, soybean oil, sunflower oil, tung oil, grape seed oil, wheat germ oil, corn oil, or any combination or mixture thereof. If the unsaturated polyester prepolymer is combined with one or more reactive monomers, the amount of the one or more reactive monomers can be about 1 wt %, about 5 wt %, about 10 wt %, about 15 wt %, or about 20 wt % to about 40 wt %, about 45 wt %, about 50 wt %, about 55 wt %, or about 60 wt %, based on the combined weight of the one or more reactive monomers and the unsaturated polyester prepolymer.
The unsaturated polyamide prepolymers can be produced by reacting one or more polyamines with one or more polyacids. The unsaturated polyamide prepolymers can also be produced by reacting one or more polyamines with one or more esters. In one or more embodiments, the one or more sites of unsaturation in the unsaturated polyamide prepolymer can be directly introduced from the polyacid and/or the polyamine, e.g., at least one of the polyacid and the polyamine can include one or more sites of unsaturation. Said another way, the unsaturated polyamide prepolymer can be produced by reacting one or more unsaturated polyacids with one or more saturated polyamines, reacting one or more unsaturated polyamines with one or more saturated polyacids, and/or by reacting one or more unsaturated polyacids with one or more unsaturated polyamines. In one or more embodiments, the sites of unsaturation in the unsaturated polyamide prepolymer can be appended to an initial prepolymer formed by reacting the polyacid and the polyamine with one or more unsaturated compounds. In another example, the unsaturation sites of the unsaturated polyamide prepolymer can be introduced via at least one of the polyamine and the poly acid, and an additional unsaturated compound. Illustrative additional unsaturated compounds can include, but are not limited to, unsaturated alcohols, unsaturated acids, unsaturated epoxides, or any mixture thereof.
The polyacid and polyamine components can be mixed, blended, or otherwise combined with one another to produce a reaction mixture. The reaction mixture can be reacted under conditions sufficient to react the polyacid with the polyamine to produce the unsaturated polyamide prepolymer. For example, the polyacid and the polyamine can be combined in a reaction vessel or container and heated to a temperature of about 50° C., about 60° C., about 70° C., or about 80° C. to about 110° C., about 125° C., about 140° C., or about 155° C. In another example, the polyacid and the polyamine can be heated to a temperature of about 60° C. to about 130° C., about 80° C. to about 115° C., about 100° C. to about 150° C., or about 75° C. to about 135° C. The polyacid and the polyamine can be reacted with one another for a time of about 10 minutes, about 30 minutes, about 1 hour, or about 2 hours to about 4 hours, about 6 hours, about 8 hours, or about 10 hours. Polyamides can also be produced or obtained via transamidation.
The progress of the reaction between the polyacid and the polyamine can be monitored via any suitable method. One method for monitoring the extent of the reaction between the polyacid and the polyamine can be through the use of infrared spectroscopy. For example, infrared spectroscopy can detect the presence of any unreacted polyacid. In one example, the reaction between the polyacid and the polyamine can be carried out until the presence of the polyacid is no longer detected. It should be noted, however, that the unsaturated polyamide prepolymer can include unreacted polyacid and/or unreacted polyamine.
The polyacid and the polyamine can be combined with one another in any desired ratio. For example, the polyamine and the polyacid can be combined with one another at a molar ratio of about 1:5, about 1:4, or about 1:2, to about 1:1, about 2:1, about 4:1, or about 6:1. In at least one example, the amount of the polyacid combined with the polyamine can be sufficient to provide a ratio of reactive acid and/or anhydride group(s) to amine groups of about 1:1 to about 2:1. For example, for each amine group present in the polyamine about 1 acid groups, about 2 acid groups, or about 3 acid groups can be present in the mixture of the polyamine and the polyacid.
Suitable polyacids can include those discussed and described above or elsewhere herein. Illustrative saturated polyamines can include, but are not limited to, ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), 1,3-propanediamine, 1,4-butanediamine, hyperbranched polyethyleneimine, or any combination or mixture thereof. Illustrative unsaturated polyamines can include those represented by the following general Formula XII below:




where R15 and R16 can independently be an organic group that can have 1 carbon atom to about 24 carbon atoms, e.g., an alkyl group containing 1 carbon atom to about 12 carbon atoms, and n can be an integer of 2 to about 12. Illustrative unsaturated polyamines having Formula XII can be prepared according to the methods discussed and described in U.S. Pat. No. 3,773,833.
The unsaturated polyether prepolymers can be produced by polymerization of allyl glycidyl ether (AGE) to form poly(allyl glycidyl ether) (PAGE). Resulted prepolymer can have pendant allyl groups. Suitable reaction conditions for producing the unsaturated polyurethane prepolymer can include those discussed and described in Lee, B. F. et al., “Poly(allyl Glycidyl Ether)-A Versatile and Functional Polyether Platform,” Journal of Polymer Science Part A: Polymer Chemistry, Vol. 49, August 2011, pp. 4498-4504. The copolymerization reaction of AGE with other monomers can be as discussed and described in Sunder, A. et al., “Copolymers of Glycidol and Glycidyl Ethers: Design of Branched Polyether Polyols by Combination of Latent Cyclic AB2 and ABR Monomers,” Macromolecules, Vol. 33, September 2000, pp. 7682-7692, and Erberich, M. et al., “Polyglycidols with Two Orthogonal Protective Groups: Preparation, Selective Deprotection, and Functionalization,” Macromolecules, Vol. 40, April 2007, pp. 3070-3079.
The unsaturated polyurethane prepolymers can be produced by reacting one or more polyisocyanates with one or more compounds having active hydrogen functionality. Moieties that provide active hydrogen functionality can include, but are not limited to, hydroxyl groups, mercaptan groups, amine groups, and carboxyl groups. In some examples, hydroxyl groups can be used as a compound having active hydrogen functionality.
Suitable polyisocyanates can include, but are not limited to, hexamethylene diisocyanate, toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), m-phenylene and p-phenylene diisocyanates, bitolylene diisocyanate, cyclohexane diisocyanate (CHDI), bis-(isocyanatomethyl) cyclohexane (H6XDI), dicyclohexylmethane diisocyanate (H12MDI), dimer acid diisocyanate (DDI), trimethyl hexamethylene diisocyanate, lysine diisocyanate and its methyl ester, methyl cyclohexane diisocyanate, 1,5-napthalene diisocyanate, xylylene and xylene diisocyanate and methyl derivatives thereof, polymethylene polyphenyl isocyanates, chlorophenylene 2,4-diisocyanate, polyphenylene diisocyanates available commercially as, for example, Mondur MR or Mondur MRS, isophorone diisocyanate (IPDI), hydrogenated methylene diphenyl isocyanate (HMDI), tetramethyl xylene diisocyanate (TMXDI), hexamethylene diisocyanate (HDI), or oligomer materials of these materials such as a trimer of IPDI, HDI or a biuret of HDI, and the like, and mixtures thereof. Triisocyanates and high-functional isocyanates can also be used. Aromatic and aliphatic diisocyanates, for example, biuret and isocyanurate derivatives can be used.
Suitable polyols for reacting with the polyisocyanates can include, but are not limited to, polyether polyols (e.g., block polyethylene and polypropylene oxide homopolymers and/or copolymers having a molecular weight of about 300 to about 3,000), alkylated polyols (e.g., polytetramethylene ether glycols), caprolactone-based polyols, and the like. In one or more embodiments, the reactants for making the polyurethane prepolymer can be or include mixtures of aliphatic and aromatic polyols, or a multi-functional, active hydrogen-bearing polymer. As such, in addition to or in lieu of polyether polyols, the hydroxyl-functional component can include derivatives of acrylates, esters, vinyls, and castor oils, as well as polymers, or any mixture thereof.
Isocyanate equivalents can predominate over active hydrogen equivalents in the polyisocyanate/polyol reaction mixture to produce a prepolymer that can include residual isocyanate groups. The isocyanate and the polyol can be combined with one another in any desired ratio. For example, the isocyanate and the polyol can be combined with one another at a molar ratio of about 1:5, about 1:4, or about 1:2, to about 1:1, about 2:1, about 4:1, or about 5:1. Suitable reaction conditions for producing the unsaturated polyurethane prepolymer can include those discussed and described in Heiss, et al., “Influence of Acids and Bases on Preparation of Urethane Polymers,” Industrial and Engineering Chemistry, Vol. 51, No. 8, August 1959, pp. 929-934. Depending upon the reaction conditions used (such as, for example, temperature and the presence of strong acids or bases, and catalysts), the reaction may lead to the formation of ureas, allophanates, biurets, or isocyanates.
Suitable amine group containing compounds that can be reacted with the polyisocyanates can include, but are not limited to, unsaturated polyamines represented by the general Formula XII discussed and described above. Suitable carboxyl group containing compounds that can be reacted with the polyisocyanates can include, but are not limited to, unsaturated aliphatic diacids. Illustrative unsaturated aliphatic diacids can include, but are not limited to, maleic acid, itaconic acid, fumaric acid, glutaconic acid, citraconic acid, traumatic acid, muconic acid, aconitic acid, or any mixture thereof.
Polyamidoamines and unsaturated glycidyl ethers suitable for producing one or more products formed by reacting the polyamidoamine and the unsaturated glycidyl ether can widely vary. The polyamidoamine can be a reaction product of a polyamine and a dicarboxylic acid. In some examples, the polyamine can be dimethylenetriamine, diethylenetriamine, triethylenetetramine, tripropylenetetramine, tetraethylenepentamine, pentaethylenehexamine, or any mixture thereof. The dicarboxylic acid can be glutaric acid, adipic acid, azelaic acid, malonic acid, suberic acid, sebacic acid, succinic acid, oxalic acid, pimelic acid, derivatives thereof, or any mixture thereof. The epihalohydrin can be epichlorohydrin, epibromohydrin, epifluorohydrin, epiiodohydrin, or any mixture thereof.
Illustrative unsaturated glycidyl ethers can be represented by general Formula VII discussed and described above. Suitable reaction products produced by reacting one or more polyamidoamines and one or more unsaturated glycidyl ethers and methods for making the reaction products can be as discussed and described in U.S. Pat. Nos. 2,864,775 and 3,280,054.
The product(s) formed by reacting the polyamidoamine(s) and the unsaturated glycidyl ether(s) can act or serve as active reducers. As used herein, the term “active reducer” refers to compounds that can participate in a cross-linking reaction, e.g., have double bonds, and also have one or more groups that can be oxidized, e.g., a tertiary amine.
In one or more embodiments, the unsaturated prepolymer can be combined with water to produce a water and unsaturated prepolymer mixture. For example, water can be mixed, blended, or otherwise combined with the unsaturated prepolymer to produce the water and unsaturated prepolymer mixture. The unsaturated prepolymer can be soluble in water. The unsaturated prepolymer can be dissolved in water to produce an aqueous unsaturated prepolymer solution. The unsaturated prepolymer can be combined with water to form an aqueous suspension, emulsion, or dispersion. The combined weight of the water and the unsaturated prepolymer, can be about 1 wt %, about 5 wt %, about 10 wt %, about 15 wt %, about 20 wt %, about 25 wt %, about 30 wt %, or about 35 wt % to about 50 wt %, about 55 wt %, about 60 wt %, about 65 wt %, about 70 wt %, or about 75 wt %, based on the combined weight of the water and the unsaturated prepolymer. The unsaturated polyester prepolymer combined with water can have a viscosity of about 20 cP, about 100 cP, about 1,000 cP, about 5,000 cP, or about 10,000 cP to about 50,000 cP, about 100,000 cP, about 200,000 cP, or about 300,000 cP at a temperature of about 25° C. The viscosity of the unsaturated polyester prepolymer and/or any other compound or composition discussed and described herein can be determined using a viscometer at a temperature of about 25° C. For example, a Brookfield Viscometer, Model DV-II+, with a small sample adapter with, for example, a number 3 spindle, can be used. The small sample adapter can allow the sample to be cooled or heated by the chamber jacket to maintain the temperature of the sample surrounding the spindle at a temperature of about 25° C.
In one or more embodiments, one or more catalysts or unsaturated polyurethane prepolymer catalysts can be used to accelerate the rate of reaction of the polyisocyanate and the polyol to produce the unsaturated polyurethane prepolymer. Suitable catalysts can include, but are not limited to, dibutyl tin dilaurate. In one or more embodiments, one or more inhibitors can be used to slow the cross-linking reaction. Suitable inhibitors can include, but are not limited to, benzoyl chloride and monophenyldichlorophosphate.
In one or more embodiments, the unsaturated prepolymer, can have a pH of about 0.5, about 2, about 3, or about 4 to about 7, about 7.5, about 8, about 8.5, or about 9. For example, the unsaturated polyester prepolymer can have a pH of about 1.5 to about 9, about 2.5 to about 7, about 1 to about 5, about 5 to about 8, or about 3 to about 6.
One or more salts can optionally be combined with the lignocellulose substrates, the free radical precursor, and the optional polyphenolic material. The amount of salt in the mixture, if present, can be about 1 wt %, about 2 wt %, or about 3 wt % to about 10 wt %, about 20 wt %, or about 30 wt %, based on the dry weight of the lignocellulose substrates. The one or more salts can be combined with the lignocellulose substrates, catalyst, and/or oxidant in any order or sequence. Illustrative salts can include, but are not limited to, aluminum, calcium, potassium, sodium, copper, zinc, magnesium, manganese, barium, and/or lithium cations. Suitable anions can include, but are not limited to, carbonates, chlorides, nitrates, silicates, acetates, formates, sulphates, phosphates, and/or other forms.
The lignocellulose substrates can include any one or more of the plant and vegetable materials discussed and described above with reference to the source for the lignins and tannins. As used herein, the term “lignocellulose” refers to a material that includes lignin and cellulose, hemicelluose, or a combination of cellulose and hemicelluloses. The starting material, from which the lignocellulose substrates can be or can be derived from, can be shaped, reduced, or otherwise formed to the appropriate dimensions by various processes such as hogging, grinding, hammer milling, tearing, shredding, and/or flaking. Other processes for producing the substrates can include skiving, cutting, slicing, and/or sawing. Suitable forms of the lignocellulose substrates can include, but are not limited to, chips, flakes, wafers, fibers, powder, shavings, sawdust or dust, veneer, strands, and/or the like. Accordingly, the term “substrate” when used in conjunction with “lignocellulose” refers to lignocellulose material or lignocellulose containing material having any desired shape such as chips, flakes, fibers, powder, shavings, sawdust or dust, veneer, strands, and/or the like. Other suitable lignocellulose substrates can include, but are not limited to, wood chips, wood fibers, wood flakes, wood strands, wood wafers, wood shavings, wood particles, wood veneer, any combination thereof, or any mixture thereof.
The particular configuration of the substrates can be based, at least in part, on the desired product. For example, particulates such as chips, fibers, shavings, sawdust or dust, or the like can be used to produce particleboards, fiberboards, and the like. The substrates can have a length of about 0.05 mm, about 0.1 mm, about 0.2 mm to about 1 mm, about 5 mm, about 10 mm, about 20 mm, about 30 mm, about 40 mm, about 50 mm, or about 100 mm, with suitable ranges including the combination of any two values. In another example, veneers, e.g., layers or sheets of wood, can be used for producing plywood, laminated veneer lumber, and the like. The veneers can have a thickness of about 0.8 mm, about 0.9 mm, about 1 mm, about 1.1 mm or about 1.2 mm to about 3 mm, about 4 mm, about 5 mm, about 6 mm, about 7 mm, about 8 mm, about 9 mm, or about 10 mm, with suitable ranges including the combination of any two values.
The lignocellulose substrates can include liquid on, about, and/or within the substrates. For example, the lignocellulose substrates can have a liquid, e.g., moisture, content of about 1 wt %, about 2 wt %, about 3 wt %, about 4 wt %, or about 5 wt % to about 7 wt %, about 9 wt %, about 11 wt %, about 13 wt %, about 15 wt %, about 17 wt %, about 19 wt %, about 21 wt %, about 23 wt %, about 25 wt %, about 27 wt %, about 29 wt %, about 31 wt %, about 33 wt %, about 35 wt %, or about 37 wt % based on a dry weight of the lignocellulose substrate, with suitable ranges including the combination of any two values. In another example, the lignocellulose substrates can have a liquid, e.g., moisture, content of about 1 wt % to about 10 wt %, about 2 wt % to about 4 wt %, about 2 wt % to about 3 wt %, about 3 wt % to about 6 wt %, about 5 wt % to about 10 wt %, about 6 wt % to about 8 wt %, or about 4 wt % to about 9 wt %. The lignocellulose substrates can be fresh, e.g., not treated or dried, or dried and/or treated. For example, the lignocellulose substrates and/or the starting material from which the lignocellulose substrates were derived can be at least partially dried. In another example, the lignocellulose substrates can be washed and/or leached with an aqueous medium such as water.
If any one or more of the components discussed and described herein include two or more different compounds, those two or more different compounds can be present in any ratio with respect to one another. Said another way, if the mixture includes a first and a second type of lignocellulose substrate, free radical precursor, and/or the polyphenolic compound, the amount of the first and second components can be present in any desired ratio. For example, if the oxidant is present in the free radical precursor and includes a first oxidant and a second oxidant, the mixture can have an oxidant composition that includes the first oxidant in an amount of about 1 wt % to about 99 wt % and conversely about 99 wt % to about 1 wt % of the second oxidant, based on the total weight of the oxidant composition, i.e., the total weight of the first and second oxidants. In another example, the amount of the first oxidant can be about 5 wt %, about 10 wt %, about 15 wt %, about 20 wt %, about 25 wt % about 30 wt %, about 35 wt %, about 40 wt %, or about 45 wt % to about 60 wt %, about 65 wt %, about 70 wt %, about 75 wt %, about 80 wt %, about 85 wt %, about 90 wt %, or about 95 wt %, based on the total weight of the first and second oxidants.
One or more salts can optionally be combined with the lignocellulose substrates, the free radical precursor, and the polyphenolic compound. The amount of salt in the mixture, if present, can be about 1 wt %, about 2 wt %, or about 3 wt % to about 10 wt %, about 20 wt %, or about 30 wt %, based on the dry weight of the lignocellulose substrates, with suitable ranges including the combination of any two values. The one or more salts can be combined with the lignocellulose substrates, catalyst, and/or oxidant in any order or sequence. Illustrative salts can include, but are not limited to, aluminum, calcium, potassium, sodium, copper, zinc, magnesium, magnesium, manganese, barium, and/or lithium cations. Suitable anions can include, but are not limited to, carbonates, chlorides, nitrates, silicates, acetates, formates, sulphates, phosphates, and/or other forms.
Illustrative composite products discussed and described herein can include, but are not limited to, particleboard, fiberboard such as medium density fiberboard (“MDF”) and/or high density fiberboard (“HDF”), plywood such as hardwood plywood and/or softwood plywood, oriented strand board (“OSB”), laminated veneer lumber (“LVL”), laminated veneer boards (“LVB”), engineered wood flooring, and the like.
The method of making one or more composite products can include a continuous or semi-continuous blending process in which the lignocellulose substrates and the other components of the mixture, e.g., the catalyst, oxidant, and the compound having at least two hydrogen atoms that are abstractable in the presence of hydroxyl radicals, can be introduced to a blender at a first or introduction region, end, area, or other location(s) configured to receive the components and the mixture can be withdrawn from the blender via one or more mixture recovery outlets. The blender can be configured to contain anywhere from a few hundred kilograms to several thousand kilograms. For example, the blender can blend about 500 kg/hr, about 5,000 kg/hr, about 10,000 kg/hr, or about 13,000 kg/hr to about 16,000 kg/hr, about 20,000 kg/hr, about 25,000 kg/hr, or about 30,000 kg/hr of the mixture. As the mixture exits the blender, the mixture can be deposited onto a conveyor belt and can be transported to one or more dryers, moistening systems, presses, and/or other processing equipment. For example, in at least one specific embodiment, a particle board product can be made blending a first or “face” mixture and a second or “core” mixture in a first and second blend, respectively. The first blender can produce about 13,600 kg/hr to about 15,900 kg/hr of a “face” mixture and the second blender can produce about 18,100 kg/hr to about 20,400 kg/hr of a “core” mixture. The “face” and “core” mixtures can be used to produce a particleboard panel or sheet, where the “face” mixture makes up the outer layers of the particleboard and the “core” mixture makes up the inner or core layer of the particleboard.
Referring to particleboard in particular, particleboard made according to one or more embodiments discussed and described herein can meet or exceed the requirements for H-1, H-2, H-3, M-0, M-1, M-S, M-2, M-3i, LD-1, and/or LD-2 grade particleboard as described in the American National Standards Institute (ANSI) for particleboard, i.e., ANSI A208.1-2009 Particleboard, approved Feb. 2, 2009. Particleboard made according to one or more embodiments discussed and described herein can meet or exceed the requirements for PBU, D-2, D-3, and/or M-3 as defined by the ANSI for particleboard, i.e., ANSI A208.1-2009 Particleboard, approved Feb. 2, 2009. For example, Tables A and B set out certain requirements for the different grades of particleboard. Referring to oriented strand board (OSB) in particular, OSB made according to one or more embodiments discussed and described herein can meet or exceed the U.S. Department of Commerce Voluntary Performance Standard PS 2. Referring to plywood in particular, plywood made according to one or more embodiments discussed and described herein can meet or exceed the U.S. Department of Commerce Voluntary Performance Standard PS 1 and/or PS-2.
In one or more embodiments, one or more additives can be combined with the lignocellulose substrates, free radical precursor, and the polyphenolic compound to produce the mixture. Illustrative additives can include, but are not limited to, waxes and/or other hydrophobic additives, water, filler material(s), extenders, surfactants, release agents, dyes, fire retardants, formaldehyde scavengers, biocides, any combination thereof, or any mixture thereof. For composite wood products, such as plywood, typical filler material(s) can include, but is not limited to, ground pecan and/or walnut shells, and typical extenders can include, for example, wheat flour. Other suitable extenders can include, but are not limited to, polysaccharides, and the like. Illustrative polysaccharides can include, but are not limited to, starch, cellulose, gums, such as guar and xanthan, alginates, pectin, gellan, any combination thereof, or any mixture thereof. Suitable polysaccharide starches can include, for example maize or corn, waxy maize, high amylose maize, potato, tapioca, and wheat starch. Other starches such as genetically engineered starches can include high amylose potato and potato amylopectin starches.
If one or more additives is present in the mixture, the amount of each additive can be about 0.01 wt % to about 50 wt %, based on the total weight of the mixture. For example, the amount of any given component or additive can be about 0.01 wt %, about 0.05 wt %, about 0.1 wt %, about 0.5 wt %, or about 1 wt % to about 3 wt %, about 5 wt %, about 7 wt %, or about 9 wt %, based on the total weight of the mixture. In another example, the amount of any given additive or component can be about 1 wt %, about 5 wt %, about 10 wt %, about 15 wt %, or about 20 wt % to about 25 wt %, about 30 wt %, about 35 wt %, about 40 wt %, or about 45 wt %, based on the total weight of the mixture. In at least one specific embodiment, one or more waxes, e.g., slack wax, can be present in the mixture and the amount of wax can be about 0.1 wt %, about 0.5 wt %, or about 0.9 wt % to about 1.5 wt %, about 2 wt %, or about 3 wt %, based on the dry weight of the lignocellulose substrates.
The composite product can have a density of about 0.5 g/cm3, about 0.55 g/cm3, about 0.6 g/cm3, about 0.63 g/cm3, about 0.65 g/cm3, about 0.67 g/cm3, or about 0.7 g/cm3 to about 0.75 g/cm3, about 0.77 g/cm3, about 0.8 g/cm3, about 0.83 g/cm3, about 0.85 g/cm3, about 0.88 g/cm3, about 0.93 g/cm3, about 0.97 g/cm3, or about 1 g/cm3. For example, the composite product can have a density of about 0.7 g/cm3 to about 0.75 g/cm3, about 0.65 g/cm3 to about 0.85 g/cm3, about 0.65 g/cm3 to about 0.8 g/cm3, about 0.67 g/cm3 to about 0.77 g/cm3, about 0.5 g/cm3, to about 1 g/cm3, about 0.5 g/cm3, to about 0.8 g/cm3, about 0.5 g/cm3 to about 0.75 g/cm3, or about 0.64 g/cm3 to about 0.8 g/cm3. In one or more embodiments, the composite product can have density of less than 1 g/cm3, less than 0.95 g/cm3, less than 0.88 g/cm3, less than 0.85 g/cm3, less than 0.83 g/cm3, less than 0.8 g/cm3, less than 0.79 g/cm3, less than 0.78 g/cm3, less than 0.77 g/cm3, less than 0.76 g/cm3, less than 0.75 g/cm3, less than 0.74 g/cm3, or less than 0.73 g/cm3.
The composite product can have an internal bond strength of about 0.3 MPa, about 0.32 MPa, about 0.34 MPa, about 0.35 MPa, about 0.37 MPa, about 0.4 MPa, about 0.42 MPa, about 0.48 MPa, about 0.52 MPa, about 0.55 MPa, or about 0.58 MPa to about 0.69 MPa, about 0.75 MPa, about 0.83 MPa, about 0.9 MPa, about 0.97 MPa, about 1.05 MPa, about 1.15 MPa, about 1.2 MPa, about 1.25 MPa, about 1.3 MPa, about 1.35 MPa, about 1.4 MPa, about 1.45 MPa, about 1.5 MPa, about 1.55 MPa, about 1.6 MPa, or about 1.7 MPa, with suitable ranges including the combination of any two values. For example, the composite product can have an internal bond strength of about 0.35 MPa to about 0.55 MPa, about 0.4 MPa to about 0.6 MPa, about 0.48 MPa to about 0.69 MPa, about 0.59 MPa to about 0.86 MPa, about 0.55 MPa to about 0.9 MPa, or about 0.51 MPa to about 0.85 MPa. In one or more embodiments, the composite product can have an internal bond strength of at least 0.33 MPa, at least 0.32 MPa, at least 0.34 MPa, at least 0.38 MPa, at least 0.41 MPa, at least 0.45 MPa, at least 0.48 MPa, at least 0.51 MPa, at least 0.55 MPa, at least 0.58 MPa, at least 0.62 MPa, at least 0.66 MPa, at least 0.69 MPa, at least 0.72 MPa, at least 0.76 MPa, or at least 0.79 MPa. The internal bond strength for each example can be determined according to the test procedure provided for in ASTM D1037-06a.
In one or more embodiments, the composite product can have a density of less than 1 g/cm3, less than 0.95 g/cm3, less than 0.9 g/cm3, less than 0.85 g/cm3, less than 0.8 g/cm3, less than 0.79 g/cm3, less than 0.78 g/cm3, less than 0.77 g/cm3, less than 0.76 g/cm3, less than 0.75 g/cm3, less than 0.74 g/cm3, or less than 0.73 g/cm3 and an internal bond strength of at least 0.3 MPa, at least 0.35 MPa, at least 0.4 MPa, at least 0.48 MPa, at least 0.51 MPa, at least 0.55 MPa, at least 0.58 MPa, at least 0.62 MPa, at least 0.65 MPa, or at least 0.69 MPa. In at least one specific example, the composite product can have a density of less than 0.8 g/cm3 and internal bond strength of at least 0.48 MPa. In at least one other specific example, the composite product can have a density of less than 0.8 g/cm3 and internal bond strength of at least 0.69 MPa. In at least one other specific example, the composite product can have a density of less than 0.73 g/cm3 and internal bond strength of at least 0.48 MPa. In still another example, the composite product can have a density of less than 0.73 g/cm3 and internal bond strength of at least 0.58 MPa.
Composite products such as particleboard, fiberboard, plywood, and oriented strand board, can have a thickness or average thickness of about 1.5 mm, about 5 mm, or about 10 mm to about 15 mm, about 20 mm, about 25 mm, about 30 mm, about 50 mm, about 100 mm, about 200 mm, or about 300 mm, with suitable ranges including the combination of any two values. Composite products such as particleboard, fiberboard, plywood, and oriented strand board can have a length of about 0.1 m, about 0.5 m, about 1 m, about 1.2 m, about 1.8 m, about 2.4 m, about 3 m, or about 3.6 m. The composite products can also have a width of about 0.1 m, about 0.5 m, about 1 m, about 1.2 m, about 1.8 m, about 2.4 m, or about 3 m.
The mixtures discussed and described herein can be free or essentially free of formaldehyde for use in the production of the composite products, e.g., wood products such as particleboard and plywood. As used herein, the term “essentially free of formaldehyde” means the mixture does not include or contain any intentionally added formaldehyde or compounds that can decompose, react, or otherwise form formaldehyde. Said another way, the term “essentially free of formaldehyde” means the mixture does not contain formaldehyde or compounds that can form formaldehyde, but may include formaldehyde present as an impurity. Accordingly, depending on the particular multifunctional aldehyde(s) used to produce the mixtures discussed and described herein, the mixture can be referred to as “no added formaldehyde” or “NAF” mixture.
The composite products discussed and described herein can exhibit a low level of formaldehyde emission. A suitable test for determining formaldehyde emission from a composite product can include ASTM D6007-02 and AST E1333-10. For example, the composite products can exhibit a formaldehyde emission of zero. In another example, the composite products can exhibit a formaldehyde emission of less than 1 part per million (“ppm”), less than 0.9 ppm, less than 0.08 ppm, less than 0.07 ppm, less than 0.06 ppm, less than 0.05 ppm, less than 0.04 ppm, less than 0.03 ppm, less than 0.02 ppm, less than 0.01 ppm, or less than 0.005 ppm.
The composite product can meet or exceed the formaldehyde emission standards required by the California Air Resources Board (“CARB”) Phase 1 (less than 0.1 parts per million “ppm” formaldehyde for particleboard), and Phase 2 (less than 0.09 ppm formaldehyde for particleboard). The composite products discussed and described herein can also meet or exceed the formaldehyde emission standards required by the Japanese JIS/JAS F*** (does not exceed 0.5 mg/L formaldehyde for particleboard), Japanese JIS/JAS F**** (does not exceed 0.3 mg/L formaldehyde for particleboard), European E1, and European E2 standards.
EXAMPLES
In order to provide a better understanding of the foregoing discussion, the following non-limiting examples are offered. Although the examples may be directed to specific embodiments, they are not to be viewed as limiting the invention in any specific respect. All parts, proportions, and percentages are by weight unless otherwise indicated.
Example I
A series of catalysts were used to produce particleboard panels, namely, comparative examples C1 and C2 and inventive Examples 1-7. For all examples, about 2,100 grams of face-grade wood particles (Southern Yellow Pine) was placed in 0.0283 m3 blender. The wood particles had a moisture content of about 5 wt % to about 7 wt %. To the wood furnish was added ammonium lignosulfonate in both liquid form and powder form, an iron containing catalyst, and about 50 wt % hydrogen peroxide solution.
The additional components of the mixture were sprayed onto the wood particles in the following order and amounts: (1) about 7 wt % of ammonium lignosulfonate (46 wt % to 49 wt % aqueous mixture) mixed with about 0.1 wt % catalyst (which differed for each example); (2) about 5 wt % of the hydrogen peroxide, and (3) about 3 wt % of the powdered ammonium lignosulfonate, where the amount of each component is based on the dry weight of the wood particles. The catalysts used in comparative examples C1 and C2 were FeSO4.7H2O, and NH4Fe(SO4)2.12H2O, respectively. The catalyst used in inventive Examples 1-7 were potassium ferricyanide (K3[Fe(CN)6]), iron ethylenediaminetetraacetic acid (Fe EDTA), iron ethylenediaminetetraacetic acid (Fe EDTA), iron (S,S)-ethylenediamine-N,N′-disuccinic acid (Fe EDDS), iron diethylenetriamine pentaacetic acid (Fe DTPA), iron ethyleneglycol bis(2-aminoethyleter)-N,N,N′,N′-tetraacetic acid (Fe EGTA), and iron trans-1,2-diaminocyclohexanetetraacetic acid (Fe CDTA), respectively. The aqueous ammonium lignosulfonate was ARBO®A02L provided by Tembec. The powdered ammonium lignosulfonate was ARBO®A02P provided by Tembec.
The FeSO4.7H2O and NH4Fe(SO4)2.12H2O were both purchased from Sigma-Aldrich and each had a purity of ≧99.0%. The (K3[Fe(CN)6]) was purchased from J. T. Baker Chemical Co. and had a purity of 99.5%. The Fe EDTA was purchased from Acros Organic and had a purity of 98%. The FeCl3 was purchased from Sigma-Aldrich and had a purity of 97%. The EDDS was purchased from Sigma-Aldrich as a 35% aq. trisodium salt solution. The DTPA was purchased from Sigma-Aldrich and had a purity of 98%. The EGTA was purchased from Sigma-Aldrich as a tetrasodium salt and had a purity of ≧97.0%. The CDTA monohydrate was purchased from Fluka and had a purity of ≧98.5%. Iron chelates were made by mixing 1.0 equiv. of aqueous solution of FeCl3 with 1.05 equiv. of aqueous solution of the corresponding sodium salt of the chelate at room temperature. Sodium salts of DTPA and CDTA chelates were made by the addition of sodium hydroxide to the corresponding chelate. Freshly prepared iron chelate solutions were used in the experiments.
The mixture or “resinated furnish” had a total moisture content of about 17 wt % to 18 wt % and was blended for an additional 2 minutes after adding the powdered ammonium lignosulfonate. The resinated furnish was placed in a 33 cm×45.7 cm×20.3 cm open container for about 30 minutes during which time the temperature of the resinated furnish was measured. For each example, the initial or starting temperature of the resinated furnish varied due to one or more factors, which included the initial temperature of the wood particles varying due how long the wood particles were allowed to cool after drying, the ambient temperature on the given day of the experiments which took place from January to July, and, as can be seen in Table 1, for the comparative examples C1 and C2 the components of the furnish were highly reactive with one another compared to Examples 1-7 and heat generated upon or shortly after formation of the mixture contributed to the differences in initial starting temperatures. The temperature of each resinated furnish during the 30 minutes is shown in Table 1 below.
















TABLE 1






Cl,
C2,

Ex. 2,
Ex. 3,
Ex. 4,
Ex. 5,
Ex. 6,
Ex. 7,



FeSO4 ×
NH4Fe(SO4)2 ×
Ex. 1,
Fe
Fe
Fe
Fe
Fe
Fe



7H2O
12H2O
K3[Fe(CN)6]
EDTA
EDTA
EDDS
DTPA
EGTA
CDTA


Time,
Temp,
Temp,
Temp,
Temp,
Temp,
Temp,
Temp,
Temp,
Temp,


min.
° C.
° C.
° C.
° C.
° C.
° C.
° C.
° C.
° C.
























2
34.4
—
26.8
25.1
26.6
—
—
36.4
29.1


3
—
34.3
—
—

33.6
34.0
—
—


4
36.3
—
27.7
25.7
26.8
—
—
37.6
29.2


6
—
36.7
29.7
26.4

34.0
34.1
38.4
29.4


8
—
—
29.7
—
27.0
34.2
34.2
—
—


9
—
—
—
—

—
—
—
29.6


10
—
—
—
26.4
27.1
34.5
—
40.4
—


11
—
—
—
—

—
—
—
29.8


12
41.4
44.0
—
26.5

—
—
41.5
—


13
—
—
—
—

34.7
—
—
30.0


14
—
—
28.7
26.6

—
34.7
42.8
—


15
—
—
—
—
27.3
—
—
—
30.2


16
—
—
29.1
26.8

—
—
—
—


18
47.9
64.0
—
26.9
27.4
—
34.9
—
—


19
—
—
—
26.9

35.2
—
—
30.4


20
—
—
29.4
26.9
27.5
—
35.0
47.7
—


21
—
90.6
—
—

—
—
—
—


22
56.8
104.0 
—
—

—
35.1
—
—


23
—
—
—
—

—
—
—
30.6


24
65.7
104.0 
29.7
—

35.4
35.1
—
—


25
—
104.0 
—
—

—
—
51.5
—


26
83.8
—
—
—

35.5
35.0
—
—


27
98.2
102.0 
—
—

—
—
—
—


28
105.1 
—
30.0
—
27.9
35.5
—
54.8
—


30
106.8 
98.4
30.1
—
28.0
35.6
35.0
57.4
30.8









As shown in Table 1, the resinated furnish of comparative examples C1 and C2 all exceeded a temperature of 40° C. in less than 30 minutes. In fact, all of the comparative examples C1 and C2 exceeded 100° C. In direct contrast, none of the inventive Examples. 1-7 exceeded a temperature of 60° C. over the 30 minute duration.
After the 30 minutes in the a 33 cm×45.7 cm×20.3 cm open container, the resinated furnish was formed into a 40.64 cm×40.64 cm×5.08 cm mat and a particleboard panel was pressed to stops configured to produce a panel having a thickness of 1.59 cm+/−0.3 cm for about 4 minutes at 165.5° C.+/−5.5° C. (total press time of about 240 seconds included about 30 seconds closing time, about 180 seconds press time, and about 30 seconds degas time). The particleboard samples were then cooled to room temperature and internal bond (IB) strength was tested according to ASTM D1037-06a. Each particleboard panel had a thickness of 1.59 cm+/−0.3 cm. The particleboard density and internal bond strength for each sample are shown in Table 2 below.










TABLE 2





Example
Catalyst
Density, g/cm3
IB, MPA


















C1
FeSO4 x 7H2O
0.774
0.49


C2
NH4Fe(SO4)2 x 12H2O
0.770
0.185


Ex. 1
K3[Fe(CN)6]
0.803
0.772


Ex. 2
Fe EDTA
0.745
0.591


Ex. 3
Fe EDTA
0.748
0.607


Ex. 4
Fe EDDS
0.742
0.458


Ex. 5
Fe DTPA
0.769
0.403


Ex. 6
Fe EGTA
0.798
0.556


Ex. 7
Fe CDTA
0.775
0.383









As shown in Table 2, all inventive Examples 1-7 had an IB strength of about 0.383 MPa or more. Comparative example C2 had a significantly lower IB strength of about 0.185 MPa. Comparative example C1 had a comparable IB strength of about 0.490 MPa, but the resinated furnish exceeded 100° C. within 30 minutes. When the resinated furnish exceeds 100° C. a substantial amount of heat and steam can be generated, which in addition to being undesirable from a manufacturing standpoint, also presents a safety hazard to people involved in the manufacturing of composite products. Particleboard panels having an IB of about 0.350 MPa or more are useful for numerous applications, which include, but are not limited to, furniture, cabinetry, flooring, and wall units.
Example II
In Example II four examples were prepared, namely, a Control, and inventive Examples 8-10 and the amount of oxidant (hydrogen peroxide) that remained present in each example after about 30 minutes was determined. Face-grade wood particles (Southern Yellow Pine) in the amount of about 2,100 g was placed in 0.0283 m3 blender. The wood particles had a moisture content of about 5 wt % to about 7 wt %. The Control example included only hydrogen peroxide, i.e., no catalyst, wood particles, or ammonium lignosulfonate were present. For Example 8, the following components were added to the wood particles in the form a fine mist while blending to produce the resinated furnish: a) about 7 wt % of ammonium lignosulfonate (46 wt % to 49 wt % aqueous mixture), b) about 5 wt % of hydrogen peroxide (50% aq.), and c) about 3 wt % of powdered ammonium lignosulfonate, where the amount of each component was based on the dry weight of the wood particles. For Examples 9 and 10, the following components were added to the wood particles while blending to produce the resinated furnish: a) about 7 wt % of ammonium lignosulfonate (46 wt % to 49 wt % aqueous mixture) mixed with about 0.275 wt % FeEDTA (Ex. 9) and about 0.22 wt % K3[Fe(CN)6] (Ex. 10), respectively, b) about 5 wt % of hydrogen peroxide (50% aq.), and c) about 3 wt % of powdered ammonium lignosulfonate, where the amount of each component was based on the dry weight of the wood particles.
The resinated furnishes of Examples 8-10 (moisture content of about 17 wt % to about 18 wt %) were blended for an additional 2 min and then placed in a 33 cm×45.7 cm×20 cm open container for about 30 min during which time the temperature of the resinated furnish was measured. A representative sample of each resinated wood furnish in the amount of about 20 g was transferred to plastic container and about 200 g of deionized water was added. For the control sample, about 0.95 g of the H2O2 was transferred to a plastic container and about 400 g of deionized water was added thereto. The H2O2 content was then analyzed using triphenylphosphine, as further discussed below. For Examples 8-10, the mixtures were hand stirred for about 5 min and poured into a funnel equipped with filter paper. For Examples 8 and 10, the filtrates were collected and the wood furnish was rinsed two more times with an additional about 800 g of deionized water (2 separate rinses of about 400 g each). For Example 9, the filtrate was collected and the wood furnish was rinsed one additional time with about 400 g of deionized water.
For Examples 8-10, the rinsed filtrates were diluted by adding about 1 mL of filtrate to a 100 mL volumetric flask and the remainder of the flask was filled with water. A 2.0 mM solution of triphenylphosphine in acetonitrile was then prepared. About 1 mL of each solution was mixed together in a plastic container and stored in the dark for 30 minutes during which time the triphenylphosphine oxidized to triphenylphosphine oxide. The triphenylphosphine oxide concentration was measured by HPLC. The triphenylphosphine and triphenylphosphine oxide (used for calibration curve) were purchased from Aldrich and had a purity of 99% and 98%, respectively. The analytical procedure using the triphenylphosphine in acetonitrile to determine the hydrogen peroxide content was conducted according to the procedure discussed and described in Pinkernell, U.; Effkemann, S.; Karst, U., Anal. Chem. 1997, 69, 3623-3627.
The results are shown in Table 3 below.










TABLE 3







Components
% H2O2 retained




















Control
H2O2
98



Ex. 8
ALS + H2O2
81



Ex. 9
ALS + FeEDTA + H2O2
63



Ex. 10
ALS + K3[Fe(CN)6] + H2O2
83










As shown in Table 3, the control example only lost about 2% of the hydrogen peroxide, which should be due to experimental error and/or decomposition of the hydrogen peroxide caused by light during the 30 minute monitoring step. Examples 8-10 each had a hydrogen peroxide concentration of about 81%, about 63%, and about 83%, respectively, that remained present after the 30 minute monitoring step. Without wishing to be bound by theory, it is believed that Ex. 9 showed a greater decrease in the H2O2 content due to rinsing the mixture only once, which most likely was insufficient to recover the additional H2O2. Also, without wishing to be bound by theory it is believed that the H2O2 not recovered could be due to decomposition of hydrogen peroxide, there may be an equilibrium between the H2O2 and the furnish, and/or the H2O2 may react with some components of the wood that can be oxidized by just H2O2.
Example III
In Example III, three inventive examples were prepared, namely, Examples 11-13. In each example, about 2,200 grams of face-grade wood particles (Southern Yellow Pine) was placed into a 0.0283 m3 blender. The wood particles had a moisture content of about 3.5 wt % to about 4 wt %. A polyphenolic material, an iron EDTA catalyst, and hydrogen peroxide (50 wt % aqueous solution) were added to the wood particles to produce a mixture. The polyphenolic material used in each example was ammonium lignosulfonate (ALS). The ALS was an aqueous ALS (Ex. 11), a two phase (aqueous and powder) ALS (Ex. 12), and a solid or powdered ALS (Ex. 13). The aqueous ALS was ARBO® A02L provided by Tembec. The powdered ALS was ARBO® A02P provided by Tembec. For Example 12, a mixture of the aqueous (ALS ARBO® A02L) and the powdered ALS (ARBO® A02P) were used.
For the liquid ALS (Ex. 11), the components of the mixture were sprayed onto the wood particles in the following order and amounts: about 6.14 wt % ALS (46 wt % to 49 wt % aqueous mixture) mixed with about 0.243 wt % FeEDTA followed by about 4.86 wt % of hydrogen peroxide, where the amount of each component was based on the dry weight of the wood particles. The mixture or “resinated furnish” had a total moisture content of about 16.4 wt % and was blended for an additional 1 minute after adding all the components.
For the two phase ALS (Ex. 12), the components of the mixture were sprayed onto the wood particles in the following order and amounts: about 3.14 wt % ALS (46 wt % to 49 wt % aqueous mixture) mixed with about 0.243 wt % FeEDTA followed by about 4.86 wt % hydrogen peroxide, followed by about 3 wt % of the powdered ALS, where the amount of each component was based on the dry weight of the wood particles. The resinated furnish had a total moisture content of about 15.7 wt % and was blended for an additional 1 minute after adding all the components.
For the solid ALS (Ex. 13), the components of the mixture were sprayed onto the wood particles in the following order and amounts: about 6.14 wt % of powdered ammonium lignosulfonate, followed by about 0.243 wt % FeEDTA (dissolved in about 120 g of warm water), followed by about 4.86 wt % of the hydrogen peroxide, where the amount of each component was based on the dry weight of the wood particles. The resinated furnish had a total moisture content of about 14.4 wt % and was blended for an additional 1 minute after adding all the components.
The resinated furnishes for each example was placed into a 40.64 cm×40.64 cm×5.08 cm form and a particleboard panel was pressed to a thickness of 1.42 cm+/−0.02 cm for about 3 minutes at about 160° C.+/−2° C. The pressing conditions included a total press time of about 180 seconds with about 60 a second closing time, about 90 second press or dwell time, and about 30 second degas time. The particleboard samples were then cooled to room temperature and the internal bond (IB) strength was measured, according to ASTM D1037-06a. Each particleboard panel had a thickness of 1.42 cm+/−0.02 cm. The particleboard density and the internal bond strength for each sample (Ex. 11-13) are shown in Table 4 below.












TABLE 4







Example
Form of ALS
Density, g/cm3
IB, MPA









Ex. 11
Liquid
0.793
0.64



Ex. 12
Liquid/Solid
0.827
0.74



Ex. 13
Solid
0.804
0.65










Example IV
In Example IV, two inventive examples were prepared, namely, Examples 14 and 15. In each example, about 2,200 grams of face-grade wood particles (Southern Yellow Pine) was placed into 0.0283 m3 blender. The wood particles had a moisture content of about 3.5 wt % to about 4 wt %. In Example 14, a lignin in the form of powdered kraft lignin, an iron EDTA catalyst, and 50 wt % hydrogen peroxide solution were combined with the wood furnish to produce a mixture. In Example 15, a blend of a blend of the powdered kraft lignin and a powdered ammonium lignosulfonate (ALS), the iron EDTA catalyst, and 50 wt % hydrogen peroxide solution were combined with the wood furnish to produce a mixture. The powdered kraft lignin had a ratio of aromatic carbon atoms plus alkenic carbon atoms to aliphatic carbon atoms of about 5.0, based on quantitative analysis of 13C NMR spectra of the powdered kraft lignin and a sulfur content of about 2.5 wt % as calculated by elemental analysis. The powdered ammonium lignosulfonate had a ratio of aromatic carbon atoms plus alkenic carbon atoms to aliphatic carbon atoms of about 1.5, based on quantitative analysis of 13C NMR spectra of the powdered ammonium lignosulfonate and a sulfur content of about 7.6 wt % as calculated by elemental analysis. The powdered ammonium lignosulfonate (ALS) was ARBO®A02P provided by Tembec.
For Example 14, the components of the mixture were sprayed onto the wood particles in the following order and amounts: about 6.14 wt % of powdered kraft lignin followed by about 0.243 wt % FeEDTA (dissolved in 120 g of water), followed by about 4.86 wt % of the hydrogen peroxide, where the amount of each component was based on the dry weight of the wood particles. The mixture or “resinated furnish” had a total moisture content of about 14.9 wt % and was blended for an additional 1 minute after adding all the components.
For Example 15, the components of the mixture were sprayed onto the wood particles in the following order and amounts: about 3.14 wt % of powdered Kraft lignin mixed with about 3.14 wt % of powdered ammonium lignosulfonate, followed by about 0.243 wt % FeEDTA (dissolved in 120 g of water), followed by about 4.86 wt % of the hydrogen peroxide, where the amount of each component was based on the dry weight of the wood particles. The mixture or “resinated furnish” had a total moisture content of about 15.3 wt % and was blended for an additional 1 minute after adding all the components.
The resinated furnish was formed into a 40.64 cm×40.64 cm×5.08 cm mat and a particleboard panel was pressed to thickness of 1.42 cm+/−0.02 cm for about 3 minutes at a temperature of about 160° C.+/−2° C. (total press time of about 180 seconds that included about 60 seconds closing time, about 90 seconds press time, and about 30 seconds degas time). The particleboard samples were then cooled to room temperature and the internal bond (IB) strength for each panel was measured according to ASTM D1037-06a. The mean particleboard density and the mean internal bond strength measured for several samples for each example are shown in Table 5 below.












TABLE 5







Example
Lignin source
Density, g/cm3
IB, MPa









Ex. 14
Kraft Lignin
0.758
0.34



Ex. 25
Kraft Lignin/ALS
0.756
0.39










Embodiments of the present disclosure further relate to any one or more of the following paragraphs:
1. A method for making a composite product, comprising: combining a plurality of lignocellulose substrates, a free radical precursor, and a polyphenolic material to produce a mixture, wherein the polyphenolic material is a in a liquid form, a solid form, or both when combined to produce the mixture; maintaining the mixture at a temperature of less than 60° C. for at least 10 minutes while retaining at least 11 wt % of the free radical precursor charged to the mixture; and then heating the mixture comprising at least 11 wt % of the free radical precursors charged to the mixture to a temperature of at least 60° C. to about 300° C. to produce a composite product having a density of less than 1 g/cm3 and an internal bond strength of at least 0.35 MPa.
2. The method according to paragraph 1, wherein the mixture is maintained at the temperature of less than 60° C. for at least 20 minutes while retaining at least 25 wt % of the free radical precursor charged to the mixture, and wherein the mixture comprising at least 25 wt % of the free radical precursor charged to the mixture is heated to the temperature of at least 60° C. to about 300° C. to produce the composite product.
3. The method according to paragraph 1 or 2, wherein the mixture is maintained at the temperature of less than 60° C. for at least 30 minutes while retaining at least 11 wt % of the free radical precursor charged to the mixture.
4. The method according to any one of paragraphs 1 to 3, wherein, prior to heating the mixture comprising at least 11 wt % of the free radical precursor charged to the mixture to the temperature of at least 60° C. to about 300° C. to produce the composite product, an amount of energy generated from the mixture due to any exothermic reaction is less than 20 cal/g.
5. The method according to any one of paragraphs 1 to 4, wherein the free radical precursor comprises a mixture of one or more oxidants and one or more catalysts.
6. The method according to any one of paragraphs 1 to 5, wherein the free radical precursor comprises a mixture of hydrogen peroxide and one or more iron containing catalysts.
7. The method according to any one of paragraphs 1 to 6, wherein the free radical precursor comprises a catalyst, and wherein the catalyst comprises a metal in the form of a complex bound to a complexing agent.
8. The method according to any one of paragraphs 1 to 7, wherein the free radical precursor comprises hydrogen peroxide.
9. The method according to any one of paragraphs 1 to 8, wherein the polyphenolic material comprises lignin, tannins, a novolac resin, modified phenol formaldehyde resin, bisphenol A, humic acids, or any mixture thereof.
10. The method according to any one of paragraphs 1 to 9, wherein the mixture comprises the polyphenolic material in the liquid form.
11. The method according to any one of paragraphs 1 to 10, wherein the mixture comprises the polyphenolic material in the solid form.
12. The method according to any one of paragraphs 1 to 11, wherein the mixture comprises the polyphenolic material in the liquid form and in the solid form.
13. The method according to any one of paragraphs 1 to 12, wherein the mixture comprises the polyphenolic material in the liquid form, and wherein the liquid form comprises a solution comprising the polyphenolic material dissolved in a liquid medium.
14. The method according to any one of paragraphs 1 to 13, wherein the mixture comprises the polyphenolic material in the liquid form and in the solid form, and wherein the polyphenolic material in the liquid form is combined with the lignocellulose substrates before the polyphenolic material in the solid form.
15. A method for making a composite product, comprising: combining a plurality of lignocellulose substrates, a free radical precursor, and a polyphenolic material to produce a mixture, wherein the polyphenolic material is in a solid form when combined to produce the mixture; and heating the mixture to produce a composite product.
16. The method according to paragraph 15, further comprising: maintaining the mixture at a temperature of less than 60° C. for at least 10 minutes while retaining at least 11 wt % of the free radical precursor charged to the mixture; and then heating the mixture comprising at least 11 wt % of the free radical precursors charged to the mixture to a temperature of at least 60° C. to about 300° C. to produce a composite product.
17. The method according to paragraph 15 or 16, wherein the polyphenolic material comprises lignin, tannins, a novolac resin, bisphenol A, modified phenol formaldehyde resin, humic acid, or any mixture thereof.
18. The method according to any one of paragraphs 15 to 17, wherein the polyphenolic material comprises powdered ammonium lignosulfonate.
19. The method according to any one of paragraphs 15 to 18, wherein the one or more free radical precursors comprise one or more catalysts and one or more oxidants, and wherein the one or more catalysts comprise potassium ferricyanide, iron ethylenediaminetetraacetic acid, iron (S,S)-ethylenediamine-N,N′-disuccinic acid, iron diethylenetriamine pentaacetic acid, iron ethlyleneglycol bis(2-aminoethyleter)-N,N,N′,N′-tetraacetic acid, iron trans-1,2-diaminocyclohexanetetraacetic acid, or any mixture thereof.
20. A composite product, comprising: an at least partially cured composition having a density of less than 1 g/cm3 and an internal bond strength of at least 0.35 MPa, wherein the composition, prior to curing, comprises a plurality of lignocellulose substrates, a free radical precursor, and a polyphenolic material, wherein the polyphenolic material is in a liquid form, a solid form, or both when combined with the plurality of lignocellulose substrates and the free radical precursor.
21. The composite product according to paragraph 20, wherein the polyphenolic material comprises lignin, tannins, a novolac resin, modified phenol formaldehyde resin, bisphenol A, humic acids, or any mixture thereof.
22. The composite product according to paragraph 20 or 21, wherein the mixture comprises the polyphenolic material in the liquid form.
23. The composite product according to paragraph 20 or 21, wherein the mixture comprises the polyphenolic material in the solid form.
24. The composite product according to paragraph 20 or 21, wherein the mixture comprises the polyphenolic material in the liquid form and in the solid form.
25. The composite product according to any one of paragraphs 20 to 24, wherein the mixture comprises the polyphenolic material in the liquid form, and wherein the liquid form comprises a solution comprising the polyphenolic material dissolved in a liquid medium.
26. The composite product according to any one of paragraphs 20 to 25, wherein the mixture comprises the polyphenolic material in the liquid form and in the solid form, and wherein the polyphenolic material in the liquid form is combined with the lignocellulose substrates before the polyphenolic material in the solid form.
27. The method or composite product according to any one of paragraphs 1 to 14 or 20 to 26, wherein the mixture comprises the polyphenolic material in the solid form, and wherein the polyphenolic material has an average particle size of about 0.05 microns to about 500 microns.
28. The method or composite product according to any one of paragraphs 1 to 14 or 20 to 26, wherein the mixture comprises the polyphenolic material in the solid form, and wherein the polyphenolic material comprises less than 15 wt % of a liquid medium.
29. The method or composite product according to any one of paragraphs 1 to 14 or 20 to 26, wherein the mixture comprises the polyphenolic material in the liquid form, and wherein the liquid form is an aqueous solution.
30. The method or composite product according to any one of paragraphs 1 to 14 or 20 to 26, wherein the mixture comprises the polyphenolic material in the liquid form, and wherein the liquid form comprises solid polyphenolic material suspended or dispersed in a liquid medium.
31. A method for making a composite product, comprising: combining a plurality of lignocellulose substrates, one or more free radical precursors, one or more polyphenolic compounds and one or more unsaturated compounds to produce a mixture; and heating the mixture to produce a composite product.
32. A method for making a composite product, comprising: combining a plurality of lignocellulose substrates, a free radical precursor, and at least one of a polyphenolic compound and an unsaturated compound to produce a mixture; and heating the mixture to produce a composite product.
33. A method for making a composite product, comprising: combining a plurality of lignocellulose substrates, a free radical precursor, a polyphenolic compound, and an unsaturated compound to produce a mixture; and heating the mixture to produce a composite product.
34. The method according to any one of paragraphs 31 to 33, wherein the mixture comprises the polyphenolic compound, and wherein the polyphenolic compound is in a liquid form, a solid form, or both when combined to produce the mixture.
35. The method according to any one of paragraphs 31 to 34, wherein the mixture comprises the unsaturated compound, and wherein the unsaturated compound has two or more unsaturated carbon-carbon bonds, wherein at least one of the unsaturated carbon-carbon bonds is a pi-bond that is not conjugated with an aromatic moiety and is capable of free radical addition.
36. The method according to any one of paragraphs 31 to 35, wherein the mixture comprises the unsaturated compound, and wherein the unsaturated compound comprises dicyclopentadiene, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, poly(ethylene glycol) diacrylate, poly(ethylene glycol) dimethacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, pentaerythritol triacrylate, polyacrylate starch, linseed oil, an unsaturated prepolymer, or any mixture thereof.
37. The method according to paragraph 36, wherein the unsaturated compound comprises the unsaturated prepolymer, and wherein the unsaturated prepolymer comprises an unsaturated polyester prepolymer, an unsaturated polyether prepolymer; an unsaturated polyamide prepolymer, an unsaturated polyurethane prepolymer, or any mixture thereof.
38. The method according to any one of paragraphs 31 to 37, wherein the mixture comprises the polyphenolic material, and wherein the polyphenolic material comprises lignin, tannins, a novolac resin, modified phenol formaldehyde resin, bisphenol A, humic acids, or any mixture thereof.
39. The method or composite product according to any one of paragraphs 1 to 38, wherein the polyphenolic material comprises lignin that is insoluble in water at a temperature of about 25° C. and having a pH of about 7.
40. The method or composite product according to any one of paragraphs 1 to 38, wherein the polyphenolic material comprises lignin, and wherein the lignin is insoluble in water at a temperature of about 25° C. and having a pH of about 7.
41. The method or composite product according to any one of paragraphs 1 to 38, wherein the polyphenolic material comprises a polyphenolic compound that is insoluble in water at a temperature of about 25° C. and having a pH of about 7.
42. The method or composite product according to any one of paragraphs 1 to 38, wherein the polyphenolic material comprises a polyphenolic compound that is soluble in water at a temperature of about 25° C. and having a pH of about 7.
43. The method or composite product according to any one of paragraphs 1 to 38, wherein the polyphenolic material comprises mixture of a polyphenolic compound that is insoluble in water at a temperature of about 25° C. and having a pH of about 7 and a polyphenolic compound that is soluble in water at a temperature of about 25° C. and having a pH of about 7.
44. The method or composite product according to any one of paragraphs 1 to 43, wherein the polyphenolic material comprises lignin, and wherein the lignin has a weight average molecular weight of about 500 to about 20,000.
45. The method or composite product according to any one of paragraphs 1 to 44, wherein the polyphenolic material comprises lignin, and wherein the lignin has a weight average molecular weight of about 1,500 to about 3,000.
46. The method or composite product according to any one of paragraphs 1 to 44, wherein the polyphenolic material comprises lignin, and wherein the lignin has a weight average molecular weight of about 9,000 to about 11,000.
47. The method or composite product according to any one of paragraphs 1 to 44, wherein the polyphenolic material comprises lignin, and wherein the lignin has a weight average molecular weight of about 5,500 to about 7,000.
48. The method or composite product according to any one of paragraphs 1 to 47, wherein the polyphenolic material comprises lignin, and wherein the lignin is free from any sulfonate groups.
49. The method or composite product according to any one of paragraphs 1 to 48, wherein the polyphenolic material comprises lignin, and wherein the lignin contains less than 3 wt % sulfur.
50. The method or composite product according to any one of paragraphs 1 to 49, wherein the polyphenolic material comprises lignin, and wherein the lignin contains less than 2.8 wt % sulfur.
51. The method or composite product according to any one of paragraphs 1 to 50, wherein the polyphenolic material comprises lignin, and wherein the lignin contains less than 2.6 wt % sulfur.
52. The method or composite product according to any one of paragraphs 1 to 51, wherein the polyphenolic material comprises lignin, and wherein the lignin contains less than 2.5 wt % sulfur.
53. The method or composite product according to any one of paragraphs 1 to 52, wherein the polyphenolic material comprises lignin, and wherein the lignin has a ratio of aromatic carbon atoms plus alkenic carbon atoms to aliphatic carbon atoms of about 1:1 to about 6:1.
54. The method or composite product according to any one of paragraphs 1 to 52, wherein the polyphenolic material comprises lignin, and wherein the lignin has a ratio of aromatic carbon atoms plus alkenic carbon atoms to aliphatic carbon atoms of about 2:1 or greater.
55. The method or composite product according to any one of paragraphs 1 to 52, wherein the polyphenolic material comprises lignin, and wherein the lignin has a ratio of aromatic carbon atoms plus alkenic carbon atoms to aliphatic carbon atoms of about 2.5:1 or greater.
56. The method or composite product according to any one of paragraphs 1 to 52, wherein the polyphenolic material comprises lignin, and wherein the lignin has a ratio of aromatic carbon atoms plus alkenic carbon atoms to aliphatic carbon atoms of about 3:1 or greater.
57. The method or composite product according to any one of paragraphs 1 to 52, wherein the polyphenolic material comprises lignin, and wherein the lignin has a ratio of aromatic carbon atoms plus alkenic carbon atoms to aliphatic carbon atoms of about 3.5:1 or greater.
58. The method or composite product according to any one of paragraphs 1 to 52, wherein the polyphenolic material comprises lignin, and wherein the lignin has a ratio of aromatic carbon atoms plus alkenic carbon atoms to aliphatic carbon atoms of about 4:1 or greater.
59. The method or composite product according to any one of paragraphs 1 to 52, wherein the polyphenolic material comprises lignin, and wherein the lignin has a ratio of aromatic carbon atoms plus alkenic carbon atoms to aliphatic carbon atoms of about 4.5:1 or greater.
60. The method or composite product according to any one of paragraphs 1 to 52, wherein the polyphenolic material comprises lignin, and wherein the lignin has a ratio of aromatic carbon atoms plus alkenic carbon atoms to aliphatic carbon atoms of about 5:1 or greater.
61. The method or composite product according to any one of paragraphs 1 to 52, wherein the polyphenolic material comprises lignin, and wherein the lignin has a ratio of aromatic carbon atoms plus alkenic carbon atoms to aliphatic carbon atoms of about 3.5:1 to about 6:1.
62. The method or composite product according to any one of paragraphs 1 to 61, wherein the polyphenolic material comprises lignin, and wherein the lignin has a solubility in water at a temperature of about 25° C. and having a pH of about 7 of less than 5 wt %.
63. The method or composite product according to any one of paragraphs 1 to 62, wherein the polyphenolic material comprises lignin, and wherein the lignin has a solubility in water at a temperature of about 25° C. and having a pH of about 7 of less than 3 wt %.
64. The method or composite product according to any one of paragraphs 1 to 63, wherein the polyphenolic material comprises lignin, and wherein the lignin has a solubility in water at a temperature of about 25° C. and having a pH of about 7 of less than 1 wt %.
65. The method or composite product according to any one of paragraphs 1 to 64, wherein the polyphenolic material comprises lignin, and wherein the lignin has a solubility in water at a temperature of about 25° C. and having a pH of about 7 of less than 0.7 wt %.
66. The method or composite product according to any one of paragraphs 1 to 65, wherein the polyphenolic material comprises lignin, and wherein the lignin has a solubility in water at a temperature of about 25° C. and having a pH of about 7 of less than 0.5 wt %.
67. The method or composite product according to any one of paragraphs 1 to 66, wherein the polyphenolic material comprises kraft lignin.
68. The method or composite product according to any one of paragraphs 1 to 66, wherein the polyphenolic material comprises one or more lignosulfonates.
69. The method or composite product according to any one of paragraphs 1 to 66, wherein the polyphenolic material comprises ammonium lignosulfonate.
70. The method or composite product according to any one of paragraphs 1 to 66, wherein the polyphenolic material comprises a mixture of kraft lignin and one or more lignosulfonates.
71. The method or composite product according to any one of paragraphs 1 to 66, wherein the polyphenolic material comprises a mixture of kraft lignin and ammonium lignosulfonate.
Certain embodiments and features have been described using a set of numerical upper limits and a set of numerical lower limits. It should be appreciated that ranges including the combination of any two values, e.g., the combination of any lower value with any upper value, the combination of any two lower values, and/or the combination of any two upper values are contemplated unless otherwise indicated. Certain lower limits, upper limits and ranges appear in one or more claims below. All numerical values are “about” or “approximately” the indicated value, and take into account experimental error and variations that would be expected by a person having ordinary skill in the art.
Various terms have been defined above. To the extent a term used in a claim is not defined above, it should be given the broadest definition persons in the pertinent art have given that term as reflected in at least one printed publication or issued patent. Furthermore, all patents, test procedures, and other documents cited in this application are fully incorporated by reference to the extent such disclosure is not inconsistent with this application and for all jurisdictions in which such incorporation is permitted.
While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

## Claims

1. A method for making a composite product, comprising:
combining a plurality of lignocellulose substrates, a free radical precursor, and a polyphenolic material to produce a mixture, wherein the free radical precursor comprises a catalyst and an oxidant, and wherein the polyphenolic material is in a liquid form, a solid form, or both when combined to produce the mixture;
maintaining the mixture at a temperature of less than 60° C. for at least 10 minutes while retaining at least 11 wt % of the oxidant charged to the mixture; and then
heating the mixture comprising at least 11 wt % of the oxidant charged to the mixture to a temperature of at least 60° C. to about 300° C. to produce the composite product.

2. The method of claim 1, wherein the mixture is maintained at the temperature of less than 60° C. for at least 30 minutes while retaining at least 11 wt % of the oxidant charged to the mixture.

3. The method of claim 1, wherein the oxidant comprises hydrogen peroxide.

4. The method of claim 1, wherein the oxidant comprises hydrogen peroxide and the catalyst comprises one or more iron containing catalysts.

5. The method of claim 1, wherein the catalyst comprises a metal in the form of a complex bound to a complexing agent.

6. The method of claim 1, wherein the polyphenolic material comprises lignin, tannins, a novolac resin, modified phenol formaldehyde resin, bisphenol A, humic acids, or any mixture thereof.

7. The method of claim 1, wherein the polyphenolic material comprises lignin, and wherein the lignin is insoluble in water at a temperature of about 25° C. and having a pH of about 7.

8. The method of claim 1, wherein the mixture comprises the polyphenolic material in the liquid form.

9. The method of claim 1, wherein the mixture comprises the polyphenolic material in the solid form.

10. The method of claim 1, wherein the mixture comprises the polyphenolic material in the liquid form and in the solid form.

11. The method of claim 1, wherein the mixture comprises the polyphenolic material in the liquid form, and wherein the polyphenolic material in the liquid form comprises a solution comprising the polyphenolic material dissolved in a liquid medium.

12. The method of claim 1, wherein the mixture comprises the polyphenolic material in the liquid form and in the solid form, wherein the polyphenolic material in the liquid form comprises lignin dissolved in a liquid medium, and wherein the polyphenolic material in the solid form comprises lignin that is insoluble in water at a temperature of about 25° C. and having a pH of about 7.

13. The method of claim 1, wherein the mixture comprises the polyphenolic material in the liquid form and in the solid form, and wherein the polyphenolic material in the liquid form is combined with the lignocellulose substrates before the polyphenolic material in the solid form or wherein the polyphenolic material in the solid form is combined with the lignocellulose substrates before the polyphenolic material in the liquid form.

14. A method for making a composite product, comprising:
combining a plurality of lignocellulose substrates, a free radical precursor, and a polyphenolic material to produce a mixture, wherein the free radical precursor comprises a catalyst and an oxidant, and wherein the polyphenolic material is in a solid form when combined to produce the mixture; and
heating the mixture comprising at least 11 wt % of the oxidant charged to the mixture to a temperature of at least 60° C. to about 300° C. to produce the composite product.

15. The method of claim 14, wherein the mixture is maintained at a temperature of less than 60° C. for at least 10 minutes prior to heating the mixture comprising at least 11 wt % of the oxidant charged to the mixture to the temperature of at least 60° C. to about 300° C. to produce the composite product.

16. The method of claim 14, wherein the polyphenolic material comprises lignin, tannins, a novolac resin, bisphenol A, modified phenol formaldehyde resin, humic acid, or any mixture thereof.

17. The method of claim 14, wherein the polyphenolic material comprises ammonium lignosulfonate, a lignin that is insoluble in water at a temperature of 25° C. and having a pH of about 7, or a mixture thereof.

18. The method of claim 14, wherein the catalyst comprises potassium ferricyanide, an iron complex of ethylenediaminetetraacetic acid, an iron complex of (S,S)-ethylenediamine-N,N′-disuccinic acid, an iron complex of diethylenetriamine pentaacetic acid, an iron complex of ethlyleneglycol bis(2-aminoethyl)-N,N,N′,N′-tetraacetic acid, an iron complex of trans-1,2-diaminocyclohexanetetraacetic acid, or any mixture thereof.

19. A method for making a composite product, comprising:
combining a plurality of lignocellulose substrates, a polyphenolic material, and a free radical precursor comprising a catalyst and an oxidant to produce a mixture, wherein the polyphenolic material is in a liquid form, a solid form, or both when combined to produce the mixture; and
heating the mixture comprising at least 11 wt % of the oxidant charged to the mixture to a temperature of at least 60° C. to about 300° C. to produce the composite product, wherein the composite product has an internal bond strength of at least 0.3 MPa, as measured according to ASTM D1037-06a.

20. The method of claim 19, wherein;
the mixture comprises the polyphenolic material in the liquid form,
the mixture comprises at least 20 wt % of the oxidant charged to the mixture when heated to the temperature of at least 60° C. to about 300° C. to produce the composite product,
the mixture is maintained at a temperature of less than 60° C. for at least 10 minutes prior to heating the mixture comprising at least 20 wt % of the oxidant charged to the mixture,
the oxidant comprises hydrogen peroxide,
the catalyst comprises potassium ferricyanide, an iron complex of ethylenediaminetetraacetic acid, an iron complex of (S,S)-ethylenediamine-N,N′-disuccinic acid, an iron complex of diethylenetriamine pentaacetic acid, an iron complex of ethyleneglycol bis(2-aminoethyl)-N,N,N′,N′-tetraacetic acid, an iron complex of trans-1,2-diaminocyclohexanetetraacetic acid, or any mixture thereof,
the polyphenolic material comprises lignin, tannins, a novolac resin, bisphenol A, modified phenol formaldehyde resin, humic acid, or any mixture thereof, and
the composite product has an internal bond strength of about 0.35 MPa to about 1.7 MPa, as measured according to ASTM D1037-06a.