Patent Description:
Thermoplastic polymers are often used to make extruded objects like films, bags, particles, and filaments. One example of a thermoplastic polymer is a polyamide. Polyamides like nylons are off-white colored polymers that have the ability to withstand elevated or low temperatures without loss of physical properties. Therefore, objects formed with polyamides can be used in demanding applications like power tools, automotive parts, gears, and appliance parts. In some instances, the application may call for the polyamide-made part to be colored. Because pigments are particulates, pigments can be difficult to homogeneously mix in the polyamide, which causes the coloring of the resultant part to be uneven.

One application where homogeneous incorporation of pigments is especially important is the rapidly growing technology area of three-dimensional (<NUM>-D) printing, also known as additive manufacturing. Although <NUM>-D printing has traditionally been used for rapid prototyping activities, this technique is being increasingly employed for producing commercial and industrial objects, which may have entirely different structural and mechanical tolerances than do rapid prototypes.

<NUM>-D printing operates by depositing either (a) small droplets or streams of a melted or solidifiable material or (b) powder particulates in precise deposition locations for subsequent consolidation into a larger object, which may have any number of complex shapes. Such deposition and consolidation processes typically occur under the control of a computer to afford layer-by-layer buildup of the larger object. In a particular example, consolidation of powder particulates may take place in a <NUM>-D printing system using a laser to promote selective laser sintering (SLS).

Powder particulates usable in <NUM>-D printing include thermoplastic polymers, including thermoplastic elastomers, metals and other solidifiable substances. One example thermoplastic polymer is nylon. Nylons are off-white colored polymers that have the ability to withstand elevated or low temperatures without loss of physical properties. Therefore, nylons can be used in demanding applications like power tools, automotive parts, gears, and appliance parts.

When using a particulate pigment in <NUM>-D printing, the particulates should be evenly dispersed throughout the small melted droplets or the power particulate, or the coloring of the final object will be uneven.

<CIT> discloses a modified high molecular weight polycaprolactam consisting of polycaprolactam having recurring carbonamide groups in the polymeric chain reacted at a temperature above the melting point of the polycaprolactam, with <NUM> to <NUM> percent by weight based on the polycaprolactam of a basic, monoepoxy compound of the formula
<CHM>
wherein R<NUM> and R<NUM>, are the same or different members selected from the group C<NUM> - C<NUM> saturated aliphatic hydrocarbon radicals selected from the group consisting of an unsubstituted radical; a substituted radical containing functional groups chemically inert to the polycaprolactam, a cycloalkyl radical, a benzyl radical, or R<NUM> and R<NUM> together form, with the nitrogen atom to which they are attached, a heterocyclic ring. Document <CIT> discloses UV absorbers covalently linked to polymers such as polyamide to reduce migration. Document <CIT> discloses spherical polyamide particles including optically absorbing compounds.

The present disclosure relates to compositions, synthesis methods, and applications of polyamides having an optical absorber pendent from the backbone of the polyamide. For example, particles may comprise a polyamide having an optical absorber pendent from the backbone of the polyamide.

Disclosed herein are methods that comprise: esterifying a hydroxyl-pendent optical absorber with a halogen-terminal aliphatic acid to yield a halogen-terminal alkyl-optical absorber; and N-alkylating a polyamide with the halogen-terminal alkyl-optical absorber to yield a polyamide having an optical absorber pendent from the polyamide's backbone (OAMB-polyamide).

Disclosed herein are methods that comprise: esterifying a carboxyl-pendent optical absorber with a halogen-terminal aliphatic alcohol to yield a halogen-terminal alkyl-optical absorber; and N-alkylating a polyamide with the modified optical absorber to yield an OAMB-polyamide.

Disclosed herein are compositions that comprise: a polyamide having an optical absorber pendent from a backbone of the polyamide, wherein the polyamide and the optical absorber are connected by an alkyl linker. wherein the polyamide and the optical absorber are connected by an alkyl linker, through an orifice to produce a film, a fiber (or a filament), particles, pellets, or the like.

Disclosed herein are methods that comprise: mixing a mixture comprising an OAMB-polyamide, a carrier fluid that is immiscible with the OAMB-polyamide, and optionally an emulsion stabilizer at a temperature greater than a melting point or softening temperature of the OAMB-polyamide and at a shear rate sufficiently high to disperse the OAMB-polyamide in the carrier fluid; and cooling the mixture to below the melting point or softening temperature of the OAMB-polyamide to form solidified particles comprising the OAMB-polyamide and the emulsion stabilizer, when present, associated with an outer surface of the solidified particles.

Disclosed herein are compositions that comprise: particles comprising an OAMB-polyamide and having a circularity of about <NUM> to about <NUM>.

Also disclosed herein are methods that comprise: depositing OAMB-polyamide particles described herein optionally in combination with other thermoplastic polymer particles upon a surface in a specified shape; and once deposited, heating at least a portion of the particles to promote consolidation thereof and form a consolidated body.

The following figures are included to illustrate certain aspects of the disclosure.

The <FIG> is a flow chart of an example method of the present disclosure.

The present disclosure relates to polyamides having an optical absorber pendent from the backbone of the polyamide and related methods. More specifically, the methods herein first esterify an optical absorber with a halogen-terminal alkyl by forming an ester bond between (a) a halogen-terminal aliphatic acid or a halogen-terminal alcohol and (b) a hydroxyl group or carboxyl group, respectively, of the optical absorber to yield a halogen-terminal alkyl-optical absorber. Then, the polyamide backbone is alkylated with the halogen-terminal alkyl-optical absorber. The result is a polyamide having an optical absorber pendent from the backbone of the polyamide, also referred to herein as an optical absorber-modified backbone of a polyamide or OAMB-polyamide. Because the optical absorber is pendent from the backbone of the polyamide, objects produced by additive manufacturing methods that include these particles should maintain an even color over time because the optical absorber cannot migrate within or leach from the object.

The present disclosure also relates to particles comprising a polyamide having an optical absorber pendent from the backbone of the polyamide (also referred to herein as an optical absorber-modified backbone of a polyamide or OAMB-polyamide) and related methods. More specifically, the present disclosure includes methods of making highly spherical polymer particles comprising the one or more OAMB-polyamides and optionally one or more other thermoplastic polymers. Said polymer particles may be useful, among other things, as starting material for additive manufacturing.

The polymer particles described herein are produced by melt emulsification methods where one or more OAMB-polyamides and optionally one or more additional thermoplastic polymers are dispersed as a melt in a carrier fluid that is immiscible with the OAMB-polyamide and additional thermoplastic polymers, if used. A sufficient amount of shear is applied to the mixture to cause the polymer melt to form droplets in the carrier fluid.

Because the optical absorber is pendent from the backbone of the polyamide, objects produced by additive manufacturing methods that include these particles should maintain an even color over time because the optical absorber cannot migrate within or leach from the object.

As used herein, the term "immiscible" refers to a mixture of components that, when combined, form two or more phases that have less than <NUM> wt% solubility in each other at ambient pressure and at room temperature or the melting point of the component if it is solid at room temperature. For example, polyethylene oxide having <NUM>,<NUM>/mol molecular weight is a solid at room temperature and has a melting point of <NUM>. Therefore, said polyethylene oxide is immiscible with a material that is liquid at room temperature if said material and said polyethylene oxide have less than <NUM> wt% solubility in each other at <NUM>.

As used herein, the term "optical absorber" refers to a molecule or portion thereof that absorbs ultraviolet or visible light.

As used herein, the term "chromophore" refers to an optical absorber where the light absorption imparts color.

As used herein, the term "fluorophore" refers to an optical absorber that re-emits an absorbed photon at a different wavelength.

As used herein, the term "thermoplastic polymer" refers to a plastic polymer material that softens and hardens reversibly on heating and cooling. Thermoplastic polymers encompass thermoplastic elastomers.

As used herein, the term "elastomer" refers to a copolymer comprising a crystalline "hard" section and an amorphous "soft" section. In the case of a polyurethane, the crystalline section may include a portion of the polyurethane comprising the urethane functionality and optional chain extender group, and the soft section may include the polyol, for instance.

As used herein, the term "polyurethane" refers to a polymeric reaction product between a diisocyanate, a polyol, and an optional chain extender.

As used herein, the term "oxide" refers to both metal oxides and non-metal oxides. For purposes of the present disclosure, silicon is considered to be a metal.

As used herein, the terms "associated," "association," and grammatical variations thereof between emulsion stabilizers and a surface refers to chemical bonding and/or physical adherence of the emulsion stabilizers to the surface. Without being limited by theory, it is believed that the associations described herein between polymers and emulsion stabilizers are primarily physical adherence via hydrogen bonding and/or other mechanisms. However, chemical bonding may be occurring to some degree.

As used herein, the term "embed" relative to nanoparticles and a surface of a polymer particle refers to the nanoparticle being at least partially extended into the surface such that polymer is in contact with the nanoparticle to a greater degree than would occur if the nanoparticle were simply laid on the surface of the polymer particle.

Herein, D10, D50, D90, and diameter span are primarily used herein to describe particle sizes. As used herein, the term "D10" refers to a diameter at which <NUM>% of the sample (on a volume basis unless otherwise specified) is comprised of particles having a diameter less than said diameter value. As used herein, the term "D50" refers to a diameter at which <NUM>% of the sample (on a volume basis unless otherwise specified) is comprised of particles having a diameter less than said diameter value. As used herein, the term "D90" refers to a diameter at which <NUM>% of the sample (on a volume basis unless otherwise specified) is comprised of particles having a diameter less than said diameter value.

As used herein, the terms "diameter span" and "span" and "span size" when referring to diameter provides an indication of the breadth of the particle size distribution and is calculated as (D90-D10)/D50 (again each D-value is based on volume, unless otherwise specified).

Particle size can be determined by light scattering techniques using a Malvern MASTERSIZER™ <NUM> or analysis of optical digital micrographs. Unless otherwise specified, light scattering techniques are used for analyzing particle size.

For light scattering techniques, the control samples were glass beads with a diameter within the range of <NUM> to <NUM> under the tradename Quality Audit Standards QAS4002™ obtained from Malvern Analytical Ltd. Samples were analyzed as dry powders, unless otherwise indicated. The particles analyzed were dispersed in air and analyzed using the AERO S dry powder dispersion module with the MASTERSIZER™ <NUM>. The particle sizes were derived using instruments software from a plot of volume density as a function of size.

Particle size measurement and diameter span can also be determined by optical digital microscopy. The optical images are obtained using a Keyence VHX-<NUM> digital microscope using version <NUM>. <NUM> software for particle size analysis (system version <NUM>).

As used herein, when referring to sieving, pore/screen sizes are described per U. Standard Sieve (ASTM E11-<NUM>).

As used herein, the terms "circularity" and "sphericity" relative to the particles refer to how close the particle is to a perfect sphere. To determine circularity, optical microscopy images are taken of the particles. The perimeter (P) and area (A) of the particle in the plane of the microscopy image is calculated (e.g., using a SYSMEX FPIA <NUM> particle shape and particle size analyzer, available from Malvern Instruments). The circularity of the particle is CEA/P, where CEA is the circumference of a circle having the area equivalent to the area (A) of the actual particle.

As used herein, the term "shear" refers to stirring or a similar process that induces mechanical agitation in a fluid.

As used herein, the term "aspect ratio" refers to length divided by width, wherein the length is greater than the width.

The melting point of a polymer, unless otherwise specified, is determined by ASTM E794-<NUM>(<NUM>) with <NUM>/min. ramping and cooling rates.

The softening temperature or softening point of a polymer, unless otherwise specified, is determined by ASTM D6090-<NUM>. The softening temperature can be measured by using a cup and ball apparatus available from Mettler-Toledo using a <NUM> gram sample with a heating rate of <NUM>/min.

Angle of repose is a measure of the flowability of a powder. Angle of repose measurements were determined using a Hosokawa Micron Powder Characteristics Tester PT-R using ASTM D6393-<NUM> "Standard Test Method for Bulk Solids" Characterized by "Carr Indices.

Hausner ratio (Hr) is a measure of the flowability of a powder and is calculated by Hr = ρtap/ρbulk, where ρbulk is the bulk density per ASTM D6393-<NUM> and ρtap is the tapped density per ASTM D6393-<NUM>.

As used herein, viscosity of carrier fluids is the kinematic viscosity at <NUM>, unless otherwise specified, measured per ASTM D445-<NUM>. For commercially procured carrier fluids (e.g., PDMS oil), the kinematic viscosity data cited herein was provided by the manufacturer, whether measured according to the foregoing ASTM or another standard measurement technique.

The present disclosure relates to polyamides having an optical absorber pendent from the backbone of the polyamide and related methods.

Examples of polyamides include, but are not limited to, polycaproamide (nylon <NUM>, polyamide <NUM>, or PA6), poly(hexamethylene succinamide) (nylon <NUM>,<NUM>, polyamide <NUM>,<NUM>, or PA4,<NUM>), polyhexamethylene adipamide (nylon <NUM>,<NUM>, polyamide <NUM>,<NUM>, or PA6,<NUM>), polypentamethylene adipamide (nylon <NUM>,<NUM>, polyamide <NUM>,<NUM>, or PA5,<NUM>), polyhexamethylene sebacamide (nylon <NUM>,<NUM>, polyamide <NUM>,<NUM>, or PA6,<NUM>), polyundecaamide (nylon <NUM>, polyamide <NUM>, or PA11), polydodecaamide (nylon <NUM>, polyamide <NUM>, or PA12), and polyhexamethylene terephthalamide (nylon 6T, polyamide 6T, or PA6T), nylon <NUM>,<NUM> (polyamide <NUM>,<NUM> or PA10,<NUM>), nylon <NUM>,<NUM> (polyamide <NUM>,<NUM> or PA10,<NUM>), nylon <NUM>,<NUM> (polyamide <NUM>,<NUM> or PA10,<NUM>), nylon <NUM>,<NUM> (polyamide <NUM>,<NUM> or PA10,<NUM>), nylon <NUM>,<NUM> (polyamide <NUM>,<NUM> or PA6,<NUM>), nylon <NUM>,<NUM> (polyamide <NUM>,<NUM> or PA6,<NUM>), nylon <NUM>,<NUM> (polyamide <NUM>,<NUM> or PA6,<NUM>), nylon <NUM>,<NUM> (polyamide <NUM>,<NUM> or PA <NUM>,<NUM>), semi-aromatic polyamide, aromatic polyamides (aramides), and the like, and any combination thereof. Copolyamides may also be used. Examples of copolyamides include, but are not limited to, PA <NUM>/<NUM>,<NUM>, PA <NUM>/<NUM>, PA <NUM>,<NUM>/<NUM>, PA <NUM>/<NUM>, PA <NUM>,<NUM>/<NUM>,<NUM>, PA <NUM>,<NUM>/<NUM>,<NUM>, PA <NUM>/<NUM>,<NUM>, PA <NUM>/<NUM>,<NUM>, PA <NUM>,<NUM>/<NUM>,<NUM>, PA 6T/<NUM>,<NUM>, and the like, and any combination thereof. Examples of polyamide elastomers include, but are not limited to, polyesteramide, polyetheresteramide, polycarbonate-esteramide, and polyether-block-amide elastomers. Herein, a polyamide followed by a single number is a polyamide having that number of backbone carbons between each nitrogen. A polyamide followed by a first number comma second number is a polyamide having the first number of backbone carbons between the nitrogens for the section having no pendent =O and the second number of backbone carbons being between the two nitrogens for the section having the pendent =O. By way of nonlimiting example, nylon <NUM>,<NUM> is [NH-(CH<NUM>)<NUM>-NH-CO-(CH<NUM>)<NUM>-CO]n. A polyamide followed by number(s) backslash number(s) are a copolymer of the polyamides indicated by the numbers before and after the backslash.

Optical absorbers may be from known families including, but not limited to, rhodamines, fluoresceins, coumarins, naphthalimides, benzoxanthenes, acridines, cyanines, oxazins, phenanthridine, pyrrole ketones, benzaldehydes, polymethines, triarylmethanes, anthraquinones, pyrazolones, quinophthalones, carbonyl dyes, diazo dyes, perinones, diketopyrrolopyrrole (DPP), dioxazine dyes, phthalocyanines, indanthrenes, benzanthrone, violanthrones, azo dyes, phthalocyanine dyes, quinacridone dyes, anthraquinone dyes, dioxagine dyes, indigo dyes, thioindigo dyes, perynone dyes, perylene dyes, isoindolene dyes, aromatic amino acids, flavins, derivatives of pyridoxyl, derivatives of chlorophyll, and the like, and any combination thereof. Optical absorbers should be chosen to be hydroxyl-pendent and/or carboxyl-pendent based on the synthesis scheme implemented.

In a first nonlimiting example embodiment of the present disclosure, an OAMB-polyamide may be produced by esterifying a hydroxyl-pendent optical absorber with a halogen-terminal aliphatic acid to yield a halogen-terminal alkyl-optical absorber; and reacting a polyamide with the halogen-terminal alkyl-optical absorber to yield an OAMB-polyamide.

In a second nonlimiting example embodiment of the present disclosure, an OAMB-polyamide may be produced by esterifying a carboxyl-pendent optical absorber with a halogen-terminal aliphatic alcohol to yield a halogen-terminal alkyl-optical absorber; and reacting a polyamide with the halogen-terminal alkyl-optical absorber to yield an OAMB-polyamide. Herein, anhydride moieties are considered carboxylic acid moieties because the anhydrides open to carboxylic acids during synthesis.

Scheme <NUM> is a nonlimiting example of a hydroxyl-pendent optical absorber (illustrated specifically as alizarin) reaction with a C<NUM> to C<NUM> halogen-terminal aliphatic acid (illustrated as a bromo-substituted aliphatic acid where n is <NUM> to <NUM>) to yield a halogen-terminal alkyl-optical absorber.

Examples of hydroxyl-pendent optical absorbers include, but are not limited to, <NUM>,<NUM>-dihydroxyanthraquinone (also known as alizarin); carminic acid; <NUM>,<NUM>-dihydroxyanthraquinone; <NUM>,<NUM>-dihydroxyanthraquinone; <NUM>-hydroxy-<NUM>-(p-tolylamino)anthraquinone (also known as oil violet and Solvent Violet <NUM>); <NUM>,<NUM>-dihydroxy-<NUM>-methoxy-<NUM>-methylanthraquinone (also known as parietin); <NUM>,<NUM>,<NUM>-trihydroxy-<NUM>-methylanthracene-<NUM>,<NUM>-dione (also known as morindone); calcein (also known as flourexon); <NUM>-carboxyfluorescein succinimidyl ester; <NUM>-carboxyfluorescein (also known as <NUM>-FAM); <NUM>',<NUM>'-dichloro-<NUM>',<NUM>'-dihydroxy-<NUM>-spiro[<NUM>-benzofuran-<NUM>,<NUM>'-xanthen]-<NUM>-one (also known as dichlorofluoresceine); fluorescein isothiocyanate; <NUM>',<NUM>'-dibromofluorescein; <NUM>(<NUM>)-carboxy-<NUM>',<NUM>'-dichlorofluorescein; <NUM>-chloro-<NUM>-[(2Z)-<NUM>-[<NUM>-[<NUM>-chloro-<NUM>-[[(2Z)-<NUM>-[[<NUM>-chloro-<NUM>-[N-[<NUM>-(<NUM>-chlorophenoxy)-<NUM>-(trifluoromethyl)phenyl]-C-hydroxycarbonimidoyl]phenyl]hydrazinylidene]-<NUM>-oxobutanoyl]amino]-<NUM>-methylanilino]-<NUM>,<NUM>-dioxobutan-<NUM>-ylidene]hydrazinyl]-N-[<NUM>-(<NUM>-chlorophenoxy)-<NUM>-(trifluoromethyl)phenyl]benzenecarboximidic acid (also known as Disazo Yellow GG and Pigment Yellow <NUM>); <NUM>-[(<NUM>-carboxy-<NUM>-oxidonaphthalen-<NUM>-yl)diazenyl]-<NUM>-chloro-<NUM>-methylbenzenesulfonate disodium (also known as Wachtung Red B and Pigment Red <NUM>); phenol dyes; <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)-<NUM>-benzofuran-<NUM>-one (also known as phenolphthalein); <NUM>,<NUM>-diamino-<NUM>,<NUM>-dihydroxy-<NUM>,<NUM>-dioxoanthracene-<NUM>-sulfonate sodium (also known as Acid Blue <NUM>); <NUM>-amino-<NUM>-hydroxy-<NUM>-phenoxyanthracene-<NUM>,<NUM>-dione (also known as Disperse Red <NUM>); <NUM>-oxo-<NUM>-(<NUM>-sulfonatophenyl)-<NUM>-[(<NUM>-sulfonatophenyl)diazenyl]-<NUM>-pyrazole-<NUM>-carboxylate trisodium (also known as tartrazine); <NUM>-chloro-<NUM>-hydroxy-<NUM>-[(<NUM>-methyl-<NUM>-oxo-<NUM>-phenyl-<NUM>-pyrazol-<NUM>-yl)diazenyl]benzenesulfonate sodium (also known as mordant red <NUM>); <NUM>-[(<NUM>-hydroxy-<NUM>,<NUM>-dioxoanthracen-<NUM>-yl)amino]-<NUM>-methylbenzenesulfonic acid sodium (also known as alizarin irisol r); <NUM>,<NUM>,<NUM>,<NUM>-tetrahydroxy-<NUM>-methyl-<NUM>,<NUM>-dioxo-<NUM>-[<NUM>,<NUM>,<NUM>-trihydroxy-<NUM>-(hydroxymethyl)oxan-<NUM>-yl]anthracene-<NUM>-carboxylic acid (also known as carmine); and the like; and any combination thereof.

Preferably the hydroxyl-pendent optical absorbers have one or two hydroxyls. Examples of hydroxyl-pendent optical absorbers include, but are not limited to, alizarin; <NUM>,<NUM>-dihydroxyanthraquinone; <NUM>,<NUM>-dihydroxyanthraquinone; <NUM>,<NUM>,<NUM>-trihydroxyanthraquinone; <NUM>-hydroxy-<NUM>-(p-tolylamino)anthraquinone; <NUM>,<NUM>-dihydroxy-<NUM>-methoxy-<NUM>-methylanthraquinone; calcein; <NUM>-carboxyfluorescein succinimidyl ester; <NUM>-carboxyfluorescein; <NUM>',<NUM>'-dichloro-<NUM>',<NUM>'-dihydroxy-<NUM>-spiro[<NUM>-benzofuran-<NUM>,<NUM>'-xanthen]-<NUM>-one; fluorescein isothiocyanate; <NUM>',<NUM>'-dibromofluorescein; <NUM>-chloro-<NUM>-[(2Z)-<NUM>-[<NUM>-[<NUM>-chloro-<NUM>-[[(2Z)-<NUM>-[[<NUM>-chloro-<NUM>-[N-[<NUM>-(<NUM>-chlorophenoxy)-<NUM>-(trifluoromethyl)phenyl]-C-hydroxycarbonimidoyl]phenyl]hydrazinylidene]-<NUM>-oxobutanoyl]amino]-<NUM>-methylanilino]-<NUM>,<NUM>-dioxobutan-<NUM>-ylidene]hydrazinyl]-N-[<NUM>-(<NUM>-chlorophenoxy)-<NUM>-(trifluoromethyl)phenyl]benzenecarboximidic acid; <NUM>-[(<NUM>-carboxy-<NUM>-oxidonaphthalen-<NUM>-yl)diazenyl]-<NUM>-chloro-<NUM>-methylbenzenesulfonate disodium; phenol dyes; <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)-<NUM>-benzofuran-<NUM>-one; <NUM>,<NUM>-diamino-<NUM>,<NUM>-dihydroxy-<NUM>,<NUM>-dioxoanthracene-<NUM>-sulfonate sodium; <NUM>-amino-<NUM>-hydroxy-<NUM>-phenoxyanthracene-<NUM>,<NUM>-dione; <NUM>-oxo-<NUM>-(<NUM>-sulfonatophenyl)-<NUM>-[(<NUM>-sulfonatophenyl)diazenyl]-<NUM>-pyrazole-<NUM>-carboxylate trisodium; <NUM>-chloro-<NUM>-hydroxy-<NUM>-[(<NUM>-methyl-<NUM>-oxo-<NUM>-phenyl-<NUM>-pyrazol-<NUM>-yl)diazenyl]benzenesulfonate sodium; <NUM>-[(<NUM>-hydroxy-<NUM>,<NUM>-dioxoanthracen-<NUM>-yl)amino]-<NUM>-methylbenzenesulfonic acid sodium; and the like; and any combination thereof.

C<NUM> to Cis halogen-terminal aliphatic acids may have the general structure of X-(CH<NUM>)n-COOH where X is bromo or chloro (probably bromo) and n is <NUM>-<NUM> (preferably <NUM>-<NUM>). Specific examples of C<NUM> to C<NUM> halogen-terminal aliphatic acids include, but are not limited to, bromoacetic acid, chloroacetic acid, <NUM>-bromopropionic acid, <NUM>-chloropropionic acid, <NUM>-bromobutyric acid, <NUM>-chlorobutyric acid, <NUM>-bromovaleric acid, <NUM>-chlorovaleric acid, <NUM>-bromohexanoic acid, <NUM>-chlorohexanoic acid, bromo-polyethyleneglycoli-carboxylic acid (bromo-PEGi-acid), bromo-PEG<NUM>-acid, bromo-PEGs-acid, bromo-PEG<NUM>-acid, bromo-PEG<NUM>-acid, bromo-PEG<NUM>-CH<NUM>COOH, bromo-PEG<NUM>-CH<NUM>COOH, and the like, and any combination thereof.

Scheme <NUM> is a nonlimiting example of a carboxyl-pendent optical absorber (illustrated specifically as <NUM>-carboxyfluorescein) reaction with a C<NUM> to C<NUM> halogen-terminal aliphatic alcohol (illustrated as a bromo-substituted aliphatic alcohol where n is <NUM> to <NUM>) to yield a halogen-terminal alkyl-optical absorber. Herein, anhydride moieties are considered carboxylic acid moieties because the anhydrides open to carboxylic acids during synthesis.

Examples of carboxyl-pendent optical absorbers include, but are not limited to, calcein (also known as flourexon); <NUM>(<NUM>)-carboxyfluorescein; <NUM>-carboxyfluorescein (also known as <NUM>-FAM); <NUM>(<NUM>)-carboxyfluorescein-N-hydroxysuccinimide ester; <NUM>-pyrenepropanoic acid; <NUM>-perylenepropanoic acid; <NUM>,<NUM>-perylenedicarboxylic acid; <NUM>(<NUM>)-carboxy-<NUM>',<NUM>'-dichlorofluorescein; calcein blue; <NUM>-[(<NUM>-carboxy-<NUM>-oxidonaphthalen-<NUM>-yl)diazenyl]-<NUM>-chloro-<NUM>-methylbenzenesulfonate disodium; <NUM>-oxo-<NUM>-(<NUM>-sulfonatophenyl)-<NUM>-[(<NUM>-sulfonatophenyl)diazenyl]-<NUM>-pyrazole-<NUM>-carboxylate trisodium; and the like; and any combination thereof.

Preferably, the carboxyl-pendent optical absorbers have one or two carboxyls. Examples of such carboxyl-pendent optical absorbers include, but are not limited to, <NUM>(<NUM>)-carboxyfluorescein; <NUM>-carboxyfluorescein; <NUM>(<NUM>)-carboxyfluorescein-N-hydroxysuccinimide ester; <NUM>-pyrenepropanoic acid; <NUM>-perylenepropanoic acid; <NUM>,<NUM>-perylenedicarboxylic acid; <NUM>(<NUM>)-carboxy-<NUM>',<NUM>'-dichlorofluorescein; calcein blue; <NUM>-[(<NUM>-carboxy-<NUM>-oxidonaphthalen-<NUM>-yl)diazenyl]-<NUM>-chloro-<NUM>-methylbenzenesulfonate disodium; <NUM>-oxo-<NUM>-(<NUM>-sulfonatophenyl)-<NUM>-[(<NUM>-sulfonatophenyl)diazenyl]-<NUM>-pyrazole-<NUM>-carboxylate trisodium; and the like; and any combination thereof.

C<NUM> to C<NUM> halogen-terminal aliphatic alcohols may have the general structure of X-(CH<NUM>)n-OH where X is bromo or chloro (probably bromo) and n is <NUM>-<NUM> (preferably <NUM>-<NUM>). Specific examples of C<NUM> to C<NUM> halogen-terminal aliphatic alcohols include, but are not limited to, <NUM>-bromoethan-<NUM>-ol, <NUM>-chloroethan-<NUM>-ol, <NUM>-bromopropan-<NUM>-ol, <NUM>-chloropropan-<NUM>-ol, <NUM>-bromopbutan-<NUM>-ol, <NUM>-chlorobutan-<NUM>-ol, <NUM>-bromopentan-<NUM>-ol, <NUM>-chloropentan-<NUM>-ol, <NUM>-bromohexan-<NUM>-ol, <NUM>-chlorohexan-<NUM>-ol, and the like, and any combination thereof.

Esterification in Scheme <NUM> or Scheme <NUM> may be achieved with Steglich esterification, which uses dicyclohexylcarbodiimide (DCC) as a coupling reagent and <NUM>-dimethylaminopyridine (DMAP) as a catalyst.

The esterification in Scheme <NUM> or Scheme <NUM> may be performed at about <NUM> to about <NUM> (or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>).

The esterification in Scheme <NUM> or Scheme <NUM> may be performed for about <NUM> minutes to about <NUM> hours (or about <NUM> minutes to about <NUM> hours, or about <NUM> hours to about <NUM> hours, or about <NUM> hours to about <NUM> hours).

The esterification in Scheme <NUM> or Scheme <NUM> may be performed in a solvent that includes, but is not limited to, dichloromethane, dimethyl sulfoxide (DMSO), N,N-dimethylformamide, acetonitrile, tetrahydrofuran, and the like, and any combination thereof.

The molar ratio of the hydroxyl-pendent optical absorber to the halogen-terminal aliphatic acid is preferably about <NUM>:<NUM> to about <NUM>:<NUM> (or about <NUM>:<NUM> to about <NUM>:<NUM>, or about <NUM>:<NUM> to about <NUM>:<NUM>, or about <NUM>:<NUM> to about <NUM>:<NUM>). The molar ratio of the carboxyl-pendent optical absorber to the halogen-terminal aliphatic alcohol is preferably about <NUM>:<NUM> to about <NUM>:<NUM> (or about <NUM>:<NUM> to about <NUM>:<NUM>, or about <NUM>:<NUM> to about <NUM>:<NUM>, or about <NUM>:<NUM> to about <NUM>:<NUM>).

Generally, the foregoing molar ratios are preferably at or close to about <NUM>:<NUM> (e.g., about <NUM>:<NUM> to about <NUM>:<NUM>) because many of the optical absorbers have more than one hydroxyl group or more than one carboxyl group. Being at or close to about <NUM>:<NUM> molar ratio mitigates esterifying the optical absorber at more than one location, which would yield a halogen-terminal alkyl-optical absorber that is likely to act as a crosslinker when reacted with a polyamide.

After the halogen-terminal alkyl-optical absorber is formed by Scheme <NUM> or Scheme <NUM>, a polyamide is N-alkylated with the halogen-terminal alkyl-optical absorber. Continuing with the nonlimiting example in Scheme <NUM>, Scheme <NUM> illustrates a reaction between the halogen-terminal alkyl-optical absorber (halogen-terminal alkyl-alizarin) and a polyamide (illustrated as nylon <NUM>) to yield an OAMB-polyamide (illustrated as an alizarin-pendent nylon <NUM>).

N-alkylation in Scheme <NUM> is performed in the presence of a strong base. Examples of strong bases include, but are not limited to, sodium t-butoxide, potassium t-butoxide, magnesium t-butoxide, calcium t-butoxide, sodium t-amylate, sodium <NUM>-methyl-<NUM>-butoxide, alkali metal amides (e.g., sodium amide, potassium amide, lithium diethylamide, and lithium diisopropylamide), sodium hydride, lithium hydride, triphenylmethyl lithium, triphenylmethyl sodium, naphthalene sodium, triphenylmethyl potassium, and the like, and any combination thereof.

The N-alkylation in Scheme <NUM> may be performed at about <NUM> to about <NUM> (or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>).

The N-alkylation in Scheme <NUM> may be performed for about <NUM> minutes to about <NUM> hours (or about <NUM> minutes to about <NUM> hours, or about <NUM> hours to about <NUM> hours, or about <NUM> hours to about <NUM> hours, or about <NUM> hours to about <NUM> hours).

The N-alkylation in Scheme <NUM> may be performed in a solvent that includes, but is not limited to, DMSO, benzylalcohol, nitrobenzene, nitroalcohol, and the like, and any combination thereof.

The molar ratio of the halogen-terminal alkyl-optical absorber to the polyamide is preferably about <NUM>:<NUM> to about <NUM>:<NUM> (or about <NUM>:<NUM> to about <NUM>:<NUM>, or about <NUM>:<NUM> to about <NUM>:<NUM>, or about <NUM>:<NUM> to about <NUM>:<NUM>).

The product of Scheme <NUM> is a polyamide having an optical absorber pendent from a backbone of the polyamide, wherein the polyamide and the optical absorber are connected by an alkyl linker preferably having <NUM>-<NUM> carbons, more preferably <NUM>-<NUM> carbons. One skilled in the art will recognize that Schemes <NUM>, <NUM>, and <NUM> can be adapted to other optical absorbers and other polyamides to yield various OAMB-polyamides. Compounds <NUM>-<NUM> are nonlimiting examples of OAMB-polyamides. <CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>.

The OAMB-polyamides described herein may be used to produce a variety of objects (or articles). The OAMB-polyamides described herein may be used alone or in combination with other thermoplastic polymers (e.g., polyamides without an optical absorber and/or other thermoplastic polymers). Examples of thermoplastic polymers that may be used in conjunction with one or more OAMB-polyamides of the present disclosure include, but are not limited to, polyamides, polyurethanes, polyethylenes, polypropylenes, polyacetals, polycarbonates, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polytrimethylene terephthalate (PTT), polyhexamethylene terephthalate, polystyrenes, polyvinyl chlorides, polytetrafluoroethenes, polyesters (e.g., polylactic acid), polyethers, polyether sulfones, polyetherether ketones, polyacrylates, polymethacrylates, polyimides, acrylonitrile butadiene styrene (ABS), polyphenylene sulfides, vinyl polymers, polyarylene ethers, polyarylene sulfides, polysulfones, polyether ketones, polyamide-imides, polyetherimides, polyetheresters, copolymers comprising a polyether block and a polyamide block (PEBA or polyether block amide), grafted or ungrafted thermoplastic polyolefins, functionalized or nonfunctionalized ethylene/vinyl monomer polymer, functionalized or nonfunctionalized ethylene/alkyl (meth)acrylates, functionalized or nonfunctionalized (meth)acrylic acid polymers, functionalized or nonfunctionalized ethylene/vinyl monomer/alkyl (meth)acrylate terpolymers, ethylene/vinyl monomer/carbonyl terpolymers, ethylene/alkyl (meth)acrylate/carbonyl terpolymers, methylmethacrylate-butadiene-styrene (MBS)-type core-shell polymers, polystyrene-block-polybutadiene-block-poly(methyl methacrylate) (SBM) block terpolymers, chlorinated or chlorosulphonated polyethylenes, polyvinylidene fluoride (PVDF), phenolic resins, poly(ethylene/vinyl acetate)s, polybutadienes, polyisoprenes, styrenic block copolymers, polyacrylonitriles, silicones, and the like, and any combination thereof. Copolymers comprising one or more of the foregoing may also be used in the methods and systems described herein.

If needed, compatibilizers may be used when combining the OAMB-polyamides described herein with other thermoplastic polymers. Compatibilizers may improve the blending efficiency and/or efficacy of the polymers. Examples of polymer compatibilizers include, but not limited to, PROPOLDER™ MPP2020 <NUM> (polypropylene, available from Polygroup Inc. ), PROPOLDER™ MPP2040 <NUM> (polypropylene, available from Polygroup Inc. ), NOVACOM™ HFS2100 (maleic anhydride functionalized high density polyethylene polymer, available from Polygroup Inc. ), KEN-REACT™ CAPS™ L™ <NUM>/L (organometallic coupling agent, available from Kenrich Petrochemicals), KEN-REACT™ CAPOW™ L™ <NUM>/H (organometallic coupling agent, available from Kenrich Petrochemicals), KEN-REACT™ LICA™ <NUM> (organometallic coupling agent, available from Kenrich Petrochemicals), KEN-REACT™ CAPS™ KPR™ <NUM>/LV (organometallic coupling agent, available from Kenrich Petrochemicals), KEN-REACT™ CAPOW™ KPR™ <NUM>/H (organometallic coupling agent, available from Kenrich Petrochemicals), KEN-REACT™ titanates & zirconates (organometallic coupling agent, available from Kenrich Petrochemicals), VISTAMAXX™ (ethylene-propylene copolymers, available from ExxonMobil), SANTOPRENE™ (thermoplastic vulcanizate of ethylene-propylene-diene rubber and polypropylene, available from ExxonMobil), VISTALON™ (ethylene-propylene-diene rubber, available from ExxonMobil), EXACT™ (plastomers, available from ExxonMobil) EXXELOR™ (polymer resin, available from ExxonMobil), FUSABOND™ M603 (random ethylene copolymer, available from Dow), FUSABOND™ E226 (anhydride modified polyethylene, available from Dow), BYNEL™ 41E710 (coextrudable adhesive resin, available from Dow), SURLYN™ <NUM> (ionomer resin, available from Dow), FUSABOND™ P353 (a chemically modified polypropylene copolymer, available from Dow), ELVALOY™ PTW (ethylene terpolymer, available from Dow), ELVALOY™ 3427AC (a copolymer of ethylene and butyl acrylate, available from Dow), LOTADER™ AX8840 (ethylene acrylate-based terpolymer, available from Arkema), LOTADER™ <NUM> (ethylene acrylate-based terpolymer, available from Arkema), LOTADER™ <NUM> (ethylene acrylate-based terpolymer, available from Arkema), LOTADER™ <NUM> (ethylene acrylate-based terpolymer, available from Arkema), LOTADER™ <NUM> (ethylene acrylate-based terpolymer, available from Arkema), LOTADER™ AX8900 (ethylene acrylate-based terpolymer, available from Arkema), LOTADER™ <NUM> (ethylene acrylate-based terpolymer, available from Arkema), BAXXODUR™ EC <NUM> (amine for epoxy, available from BASF), BAXXODUR™ EC <NUM> (amine for epoxy, available from BASF), BAXXODUR™ EC <NUM> (amine for epoxy, available from BASF), BAXXODUR™ EC <NUM> (amine for epoxy, available from BASF), BAXXODUR™ EC <NUM> (amine for epoxy, available from BASF), BAXXODUR™ EC <NUM> (amine for epoxy, available from BASF), BAXXODUR™ EC <NUM> (amine for epoxy, available from BASF), styrenics, polypropylene, polyamides, polycarbonate, EASTMAN™ G-<NUM> (a maleic anhydride grafted polypropylene, available from Eastman), RETAIN™ (polymer modifier available from Dow), AMPLIFY TY™ (maleic anhydride grafted polymer, available from Dow), INTUNE™ (olefin block copolymer, available from Dow), and the like, and any combination thereof.

Methods for producing objects include, but are not limited to, melt extrusion, injection molding, compression molding, melt spinning, melt emulsification, spray drying (e.g., to form particles), cryogenic milling (or cryogenic grinding), freeze drying polymer dispersions, precipitation of polymer dispersions, and the like, and any hybrid thereof.

Examples of articles that may be produced by such methods where the OAMB-polyamide may be all or a portion of said articles include, but are not limited to, particles, films, packaging, toys, household goods, automotive parts, aerospace/aircraft-related parts, containers (e.g., for food, beverages, cosmetics, personal care compositions, medicine, and the like), shoe soles, furniture parts, decorative home goods, plastic gears, screws, nuts, bolts, cable ties, jewelry, art, sculpture, medical items, prosthetics, orthopedic implants, production of artifacts that aid learning in education, <NUM>-D anatomy models to aid in surgeries, robotics, biomedical devices (orthotics), home appliances, dentistry, electronics, sporting goods, and the like. Further, particles may be useful in applications that include, but are not limited to, paints, powder coatings, inkjet materials, electrophotographic toners, <NUM>-D printing, and the like.

The OAMB-polyamides described herein may have a specific chemical fingerprint that is useful in identifying objects, tracking objects, authenticating objects, and/or determining the health of objects. Further, the placement of where the OAMB-polyamides are located in the objects is used as another layer of fingerprinting the objects for identifying objects, tracking objects, authenticating objects, and/or determining the health of objects.

Methods of identifying objects, tracking objects, authenticating objects, and/or determining the health of objects may include (a) exposing the object comprising OAMB-polyamides to electromagnetic radiation (e.g., for fluorophores preferably at a wavelength of <NUM> or less or <NUM> or greater); (b) sensing one or more spectra related to the electromagnetic radiation absorbed and/or reemitted (e.g., for fluorophores preferably the photoluminescence emitted between <NUM> to <NUM>); and (c) comparing the spectra to the known spectra for the optical absorbers used in said object or a portion thereof. Optionally, the location of where the spectra area is located on the object may be compared to the known location where the spectra area should be. The comparison(s) can be used for identifying and/or authenticating the object. For tracking, the comparison(s) may be done and/or the detected spectra and/or spectra area may be logged into a database along with the physical location of the object. Further, the health of objects that wear and/or crack can be ascertained. For example, a core portion of the article may comprise optical absorbers and an outer portion may cover the core portion and not comprise the optical absorbers (or comprise different optical absorbers). Then, when comparing spectra, the appearance of spectral features for the optical absorbers in the core may indicate that the object is at or near the end of life.

By way of nonlimiting example, <NUM>-D printing processes of the present disclosure may comprise: depositing particles comprising one or more OAMB-polyamides of the present disclosure (and optionally one or more other thermoplastic polymers and/or one or more compatibilizers) upon a surface in a specified shape, and once deposited, heating at least a portion of the particles to promote consolidation thereof and form a consolidated body (object), such that the consolidated body has a void percentage of about <NUM>% or less after being consolidated. For example, heating and consolidation of the thermoplastic polymer particles may take place in a <NUM>-D printing apparatus employing a laser, such that heating and consolidation take place by selective laser sintering.

By way of nonlimiting example, <NUM>-D printing processes of the present disclosure may comprise: extruding a filament comprising one or more OAMB-polyamides of the present disclosure (and optionally one or more other thermoplastic polymers and/or one or more compatibilizers) through an orifice, wherein the filament becomes a polymer melt upon extrusion; depositing the polymer melt as a first layer on a platform; cooling the layer; depositing an additional layer of the polymer melt on the first layer; cooling the additional layer; repeating depositing and cooling for at least one additional layer to produce a <NUM>-D shape.

Yet another nonlimiting example is a method comprising: extruding a polymer melt comprising one or more OAMB-polyamides of the present disclosure (and optionally one or more other thermoplastic polymers and/or one or more compatibilizers) through an orifice to produce a film, a fiber (or a filament), particles, pellets, or the like.

The FIGURE is a flow chart of a nonlimiting example method <NUM> of the present disclosure. Thermoplastic polymer <NUM> (comprising one or more OAMB-polyamides and optionally one or more other thermoplastic polymers), carrier fluid <NUM>, and optionally emulsion stabilizer <NUM> are combined <NUM> to produce a mixture <NUM>. The components <NUM>, <NUM>, and <NUM> can be added in any order and include mixing and/or heating during the process of combining <NUM> the components <NUM>, <NUM>, and <NUM>.

The mixture <NUM> is then processed <NUM> by applying sufficiently high shear to the mixture <NUM> at a temperature greater than the melting point or softening temperature of the thermoplastic polymer <NUM> to form a melt emulsion <NUM>. Because the temperature is above the melting point or softening temperature of the thermoplastic polymer <NUM>, the thermoplastic polymer <NUM> becomes a polymer melt. The shear rate should be sufficient enough to disperse the polymer melt in the carrier fluid <NUM> as droplets (i.e., the polymer emulsion <NUM>). Without being limited by theory, it is believed that, all other factors being the same, increasing shear should decrease the size of the droplets of the polymer melt in the carrier fluid <NUM>. However, at some point there may be diminishing returns on increasing shear and decreasing droplet size or may be disruptions to the droplet contents that decrease the quality of particles produced therefrom.

The melt emulsion <NUM> inside and/or outside the mixing vessel is then cooled <NUM> to solidify the polymer droplets into thermoplastic polymer particles (also referred to as solidified thermoplastic polymer particles). The cooled mixture <NUM> can then be treated <NUM> to isolate the thermoplastic polymer particles <NUM> from other components <NUM> (e.g., the carrier fluid <NUM>, excess emulsion stabilizer <NUM>, and the like) and wash or otherwise purify the thermoplastic polymer particles <NUM>. The thermoplastic polymer particles <NUM> comprise the thermoplastic polymer <NUM> and, when included, at least a portion of the emulsion stabilizer <NUM> coating the outer surface of the thermoplastic polymer particles <NUM>. Emulsion stabilizers <NUM>, or a portion thereof, may be deposited as a uniform coating on the thermoplastic polymer particles <NUM>. In some instances, which may be dependent upon non-limiting factors such as the temperature (including cooling rate), the type of thermoplastic polymer <NUM>, and the types and sizes of emulsion stabilizers <NUM>, the nanoparticles of emulsion stabilizers <NUM> may become at least partially embedded within the outer surface of thermoplastic polymer particles <NUM> in the course of becoming associated therewith. Even without embedment taking place, at least the nanoparticles within emulsion stabilizers <NUM> may remain robustly associated with thermoplastic polymer particles <NUM> to facilitate their further use. In contrast, dry blending already formed thermoplastic polymer particulates (e.g., formed by cryogenic grinding or precipitation processes) with a flow aid like silica nanoparticles does not result in a robust, uniform coating of the flow aid upon the thermoplastic polymer particulates.

Advantageously, carrier fluids and washing solvents of the systems and methods described herein (e.g., method <NUM>) can be recycled and reused. One skilled in the art will recognize any necessary cleaning of used carrier fluid and solvent necessary in the recycling process.

The thermoplastic polymer <NUM> and carrier fluid <NUM> should be chosen such that at the various processing temperatures (e.g., from room temperature to process temperature) the thermoplastic polymer <NUM> and carrier fluid <NUM> are immiscible. An additional factor that may be considered is the differences in (e.g., a difference or a ratio of) viscosity at process temperature between the molten polyamide <NUM> and the carrier fluid <NUM>. The differences in viscosity may affect droplet breakup and particle size distribution. Without being limited by theory, it is believed that when the viscosities of the molten polyamide <NUM> and the carrier fluid <NUM> are too similar, the circularity of the product as a whole may be reduced where the particles are more ovular and more elongated structures are observed.

The thermoplastic polymers <NUM> comprises one or more OAMB-polyamides and optionally one or more other thermoplastic polymers. Examples of other thermoplastic polymers include, but are not limited to, polyamides, polyurethanes, polyethylenes, polypropylenes, polyacetals, polycarbonates, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polytrimethylene terephthalate (PTT), polyhexamethylene terephthalate, polystyrenes, polyvinyl chlorides, polytetrafluoroethenes, polyesters (e.g., polylactic acid), polyethers, polyether sulfones, polyetherether ketones, polyacrylates, polymethacrylates, polyimides, acrylonitrile butadiene styrene (ABS), polyphenylene sulfides, vinyl polymers, polyarylene ethers, polyarylene sulfides, polysulfones, polyether ketones, polyamide-imides, polyetherimides, polyetheresters, copolymers comprising a polyether block and a polyamide block (PEBA or polyether block amide), grafted or ungrafted thermoplastic polyolefins, functionalized or nonfunctionalized ethylene/vinyl monomer polymer, functionalized or nonfunctionalized ethylene/alkyl (meth)acrylates, functionalized or nonfunctionalized (meth)acrylic acid polymers, functionalized or nonfunctionalized ethylene/vinyl monomer/alkyl (meth)acrylate terpolymers, ethylene/vinyl monomer/carbonyl terpolymers, ethylene/alkyl (meth)acrylate/carbonyl terpolymers, methylmethacrylate-butadiene-styrene (MBS)-type core-shell polymers, polystyrene-block-polybutadiene-block-poly(methyl methacrylate) (SBM) block terpolymers, chlorinated or chlorosulphonated polyethylenes, polyvinylidene fluoride (PVDF), phenolic resins, poly(ethylene/vinyl acetate)s, polybutadienes, polyisoprenes, styrenic block copolymers, polyacrylonitriles, silicones, and the like, and any combination thereof. Copolymers comprising one or more of the foregoing may also be used in the methods and systems of the present disclosure.

The other thermoplastic polymers in the compositions and methods of the present disclosure may be elastomeric or non-elastomeric. Some of the foregoing examples of other thermoplastic polymers may be elastomeric or non-elastomeric depending on the exact composition of the polymer. For example, polyethylene that is a copolymer of ethylene and propylene may be elastomeric or not depending on the amount of propylene in the polymer.

Thermoplastic elastomers generally fall within one of six classes: styrenic block copolymers, thermoplastic polyolefin elastomers, thermoplastic vulcanizates (also referred to as elastomeric alloys), thermoplastic polyurethanes, thermoplastic copolyesters, and thermoplastic polyamides (typically block copolymers comprising polyamide). Examples of thermoplastic elastomers can be found in the "<NPL>. Examples of thermoplastic elastomers include, but are not limited to, elastomeric polyamides, polyurethanes, copolymers comprising a polyether block and a polyamide block (PEBA or polyether block amide), methyl methacrylate-butadiene-styrene (MBS)-type core-shell polymers, polystyrene-block-polybutadiene-block-poly(methyl methacrylate) (SBM) block terpolymers, polybutadienes, polyisoprenes, styrenic block copolymers, and polyacrylonitriles), silicones, and the like. Elastomeric styrenic block copolymers may include at least one block selected from the group of: isoprene, isobutylene, butylene, ethylene/butylene, ethylene-propylene, and ethylene-ethylene/propylene. More specific elastomeric styrenic block copolymer examples include, but are not limited to, poly(styrene-ethylene/butylene), poly(styrene-ethylene/butylene-styrene), poly(styrene-ethylene/propylene), styrene-ethylene/propylene-styrene), poly(styrene-ethylene/propylene-styrene-ethylene-propylene), poly(styrene-butadiene-styrene), poly(styrene-butylene-butadiene-styrene), and the like, and any combination thereof.

Examples of polyamides include, but are not limited to, polycaproamide, poly(hexamethylene succinamide), polyhexamethylene adipamide, polypentamethylene adipamide, polyhexamethylene sebacamide, polyundecaamide, polydodecaamide, polyhexamethylene terephthalamide, nylon <NUM>,<NUM>, nylon <NUM>,<NUM>, nylon <NUM>,<NUM>, nylon <NUM>,<NUM>, nylon <NUM>,<NUM>, nylon <NUM>,<NUM>, nylon <NUM>,<NUM>, nylon <NUM>,<NUM>, a semi-aromatic polyamide, an aromatic polyamide, any copolymer thereof, and any combination thereof. Copolyamides may also be used. Examples of copolyamides include, but are not limited to, PA <NUM>/<NUM>, PA <NUM>/<NUM>, PA <NUM>/<NUM>, PA <NUM>/<NUM>, PA <NUM>/<NUM>, PA <NUM>/<NUM>, PA <NUM>/<NUM>, PA <NUM>/<NUM>, PA <NUM>/<NUM>, and the like, and any combination thereof. Examples of polyamide elastomers include, but are not limited to, polyesteramide, polyetheresteramide, polycarbonate-esteramide, and polyether-block-amide elastomers.

Examples of polyurethanes include, but are not limited to, polyether polyurethanes, polyester polyurethanes, mixed polyether and polyester polyurethanes, and the like, and any combination thereof. Examples of thermoplastic polyurethanes include, but are not limited to, poly[<NUM>,<NUM>'-methylenebis(phenylisocyanate)-alt-<NUM>,<NUM>-butanediol/di(propylene glycol)/polycaprolactone], ELASTOLLAN® 1190A (a polyether polyurethane elastomer, available from BASF), ELASTOLLAN® 1190A10 (a polyether polyurethane elastomer, available from BASF), and the like, and any combination thereof.

Compatibilizers may optionally be used to improve the blending efficiency and efficacy OAMB-polyamides with one or more thermoplastic polymers. Examples of polymer compatibilizers include, but not limited to, PROPOLDER™ MPP2020 <NUM> (polypropylene, available from Polygroup Inc. ), PROPOLDER™ MPP2040 <NUM> (polypropylene, available from Polygroup Inc. ), NOVACOM™ HFS2100 (maleic anhydride functionalized high density polyethylene polymer, available from Polygroup Inc. ), KEN-REACT™ CAPS™ L™ <NUM>/L (organometallic coupling agent, available from Kenrich Petrochemicals), KEN-REACT™ CAPOW™ L™ <NUM>/H (organometallic coupling agent, available from Kenrich Petrochemicals), KEN-REACT™ LICA™ <NUM> (organometallic coupling agent, available from Kenrich Petrochemicals), KEN-REACT™ CAPS™ KPR™ <NUM>/LV (organometallic coupling agent, available from Kenrich Petrochemicals), KEN-REACT™ CAPOW™ KPR™ <NUM>/H (organometallic coupling agent, available from Kenrich Petrochemicals), KEN-REACT™ titanates & zirconates (organometallic coupling agent, available from Kenrich Petrochemicals), VISTAMAXX™ (ethylene-propylene copolymers, available from ExxonMobil), SANTOPRENE™ (thermoplastic vulcanizate of ethylene-propylene-diene rubber and polypropylene, available from ExxonMobil), VISTALON™ (ethylene-propylene-diene rubber, available from ExxonMobil), EXACT™ (plastomers, available from ExxonMobil) EXXELOR™ (polymer resin, available from ExxonMobil), FUSABOND™ M603 (random ethylene copolymer, available from Dow), FUSABOND™ E226 (anhydride modified polyethylene, available from Dow), BYNEL™ 41E710 (coextrudable adhesive resin, available from Dow), SURLYN™ <NUM> (ionomer resin, available from Dow), FUSABOND™ P353 (a chemically modified polypropylene copolymer, available from Dow), ELVALOY™ PTW (ethylene terpolymer, available from Dow), ELVALOY™ 3427AC (a copolymer of ethylene and butyl acrylate, available from Dow), LOTADER™ AX8840 (ethylene acrylate-based terpolymer, available from Arkema), LOTADER™ <NUM> (ethylene acrylate-based terpolymer, available from Arkema), LOTADER™ <NUM> (ethylene acrylate-based terpolymer, available from Arkema), LOTADER™ <NUM> (ethylene acrylate-based terpolymer, available from Arkema), LOTADER™ <NUM> (ethylene acrylate-based terpolymer, available from Arkema), LOTADER™ AX8900 (ethylene acrylate-based terpolymer, available from Arkema), LOTADER™ <NUM> (ethylene acrylate-based terpolymer, available from Arkema), BAXXODUR™ EC <NUM> (amine for epoxy, available from BASF), BAXXODUR™ EC <NUM> (amine for epoxy, available from BASF), BAXXODUR™ EC <NUM> (amine for epoxy, available from BASF), BAXXODUR™ EC <NUM> (amine for epoxy, available from BASF), BAXXODUR™ EC <NUM> (amine for epoxy, available from BASF), BAXXODUR™ EC <NUM> (amine for epoxy, available from BASF), BAXXODUR™ EC <NUM> (amine for epoxy, available from BASF), styrenics, polypropylene, polyamides, polycarbonate, EASTMAN™ G-<NUM> (a maleic anhydride grafted polypropylene, available from Eastman), RETAIN™ (polymer modifier available from Dow), AMPLIFY TY™ (maleic anhydride grafted polymer, available from Dow), INTUNE™ (olefin block copolymer, available from Dow), and the like, and any combination thereof.

The thermoplastic polymers <NUM> (comprising one or more OAMB-polyamides and optionally one or more other thermoplastic polymers) may have a melting point or softening temperature of about <NUM> to about <NUM> (or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>).

The thermoplastic polymers <NUM> may have a glass transition temperature (ASTM E1356-<NUM>(<NUM>) with <NUM>/min. ramping and cooling rates) of about -<NUM> to about <NUM> (or about -<NUM> to about <NUM>, or about -<NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>).

The thermoplastic polymers <NUM> may optionally comprise an additive. Typically, the additive would be present before addition of the thermoplastic polymers <NUM> to the mixture <NUM>. Therefore, in the thermoplastic polymer melt droplets and resultant thermoplastic polymer particles, the additive is dispersed throughout the thermoplastic polymer. Accordingly, for clarity, this additive is referred to herein as an "internal additive. " The internal additive may be blended with the thermoplastic polymer just prior to making the mixture <NUM> or well in advance.

When describing component amounts in the compositions described herein (e.g., the mixture <NUM> and thermoplastic polymer particles <NUM>), a weight percent based on the thermoplastic polymer <NUM> not inclusive of the internal additive. For example, a composition comprising <NUM> wt% of emulsion stabilizer by weight of <NUM> of a thermoplastic polymer <NUM> comprising <NUM> wt% internal additive and <NUM> wt% thermoplastic polymer is a composition comprising <NUM> of emulsion stabilizer, <NUM> of thermoplastic polymer, and <NUM> of internal additive.

The internal additive may be present in the thermoplastic polymer <NUM> at about <NUM> wt% to about <NUM> wt% (or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%) of the thermoplastic polymer <NUM>. For example, the thermoplastic polymer <NUM> may comprise about <NUM> wt% to about <NUM> wt% of a thermoplastic polymer and about <NUM> wt% to about <NUM> wt% of an internal additive like glass fiber or carbon fiber.

Examples of internal additives include, but are not limited to, fillers, strengtheners, pigments, pH regulators, and the like, and combinations thereof. Examples of fillers include, but are not limited to, glass fibers, glass particles, mineral fibers, carbon fiber, oxide particles (e.g., titanium dioxide and zirconium dioxide), metal particles (e.g., aluminum powder), and the like, and any combination thereof. Examples of pigments include, but are not limited to, organic pigments, inorganic pigments, carbon black, and the like, and any combination thereof.

The thermoplastic polymer <NUM> may be present in the mixture <NUM> at about <NUM> wt% to about <NUM> wt% (or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%) of the thermoplastic polymer <NUM> and carrier fluid <NUM> combined.

Suitable carrier fluids <NUM> have a viscosity at <NUM> of about <NUM>,<NUM> cSt to about <NUM>,<NUM> cSt (or about <NUM>,<NUM> cSt to about <NUM>,<NUM> cSt, or about <NUM>,<NUM> cSt to about <NUM>,<NUM> cSt, or about <NUM>,<NUM> cSt to about <NUM>,<NUM> cSt).

Examples of carrier fluids <NUM> include, but are not limited to, silicone oil, fluorinated silicone oils, perfluorinated silicone oils, polyethylene glycols, alkyl-terminal polyethylene glycols (e.g., C1-C4 terminal alkyl groups like tetraethylene glycol dimethyl ether (TDG)), paraffins, liquid petroleum jelly, vison oils, turtle oils, soya bean oils, perhydrosqualene, sweet almond oils, calophyllum oils, palm oils, parleam oils, grapeseed oils, sesame oils, maize oils, rapeseed oils, sunflower oils, cottonseed oils, apricot oils, castor oils, avocado oils, jojoba oils, olive oils, cereal germ oils, esters of lanolic acid, esters of oleic acid, esters of lauric acid, esters of stearic acid, fatty esters, higher fatty acids, fatty alcohols, polysiloxanes modified with fatty acids, polysiloxanes modified with fatty alcohols, polysiloxanes modified with polyoxy alkylenes, and the like, and any combination thereof. Examples of silicone oils include, but are not limited to, polydimethylsiloxane, methylphenylpolysiloxane, an alkyl modified polydimethylsiloxane, an alkyl modified methylphenylpolysiloxane, an amino modified polydimethylsiloxane, an amino modified methylphenylpolysiloxane, a fluorine modified polydimethylsiloxane, a fluorine modified methylphenylpolysiloxane, a polyether modified polydimethylsiloxane, a polyether modified methylphenylpolysiloxane, and the like, and any combination thereof. When the carrier fluid <NUM> comprises two or more of the foregoing, the carrier fluid <NUM> may have one or more phases. For example, polysiloxanes modified with fatty acids and polysiloxanes modified with fatty alcohols (preferably with similar chain lengths for the fatty acids and fatty alcohols) may form a single-phase carrier fluid <NUM>. In another example, a carrier fluid <NUM> comprising a silicone oil and an alkyl-terminal polyethylene glycol may form a two-phase carrier fluid <NUM>.

The carrier fluid <NUM> may be present in the mixture <NUM> at about <NUM> wt% to about <NUM> wt% (or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%) of the thermoplastic polymer <NUM> and carrier fluid <NUM> combined.

In some instances, the carrier fluid <NUM> may have a density of about <NUM>/cm<NUM> to about <NUM>/cm<NUM>, and the thermoplastic polymer <NUM> has a density of about <NUM>/cm<NUM> to about <NUM>/cm<NUM>, wherein the thermoplastic polymer has a density similar, lower, or higher than the density of the carrier fluid.

The emulsion stabilizers used in the methods and compositions of the present disclosure may comprise nanoparticles (e.g. oxide nanoparticles, carbon black, polymer nanoparticles, and combinations thereof), surfactants, and the like, and any combination thereof.

Oxide nanoparticles may be metal oxide nanoparticles, non-metal oxide nanoparticles, or mixtures thereof. Examples of oxide nanoparticles include, but are not limited to, silica, titania, zirconia, alumina, iron oxide, copper oxide, tin oxide, boron oxide, cerium oxide, thallium oxide, tungsten oxide, and the like, and any combination thereof. Mixed metal oxides and/or non-metal oxides, like aluminosilicates, borosilicates, and aluminoborosilicates, are also inclusive in the term metal oxide. The oxide nanoparticles may by hydrophilic or hydrophobic, which may be native to the particle or a result of surface treatment of the particle. For example, a silica nanoparticle having a hydrophobic surface treatment, like dimethyl silyl, trimethyl silyl, and the like, may be used in methods and compositions of the present disclosure. Additionally, silica with functional surface treatments like methacrylate functionalities may be used in methods and compositions of the present disclosure. Unfunctionalized oxide nanoparticles may also be suitable for use as well.

Commercially available examples of silica nanoparticles include, but are not limited to, AEROSIL® particles available from Evonik (e.g., AEROSIL® R812S (about <NUM> average diameter silica nanoparticles having a hydrophobically modified surface and a BET surface area of <NUM>±<NUM><NUM>/g), AEROSIL® RX50 (about <NUM> average diameter silica nanoparticles having a hydrophobically modified surface and a BET surface area of <NUM>±<NUM><NUM>/g), AEROSIL® <NUM> (silica nanoparticles having a hydrophilically modified surface and a BET surface area of <NUM>±<NUM><NUM>/g), and the like, and any combination thereof.

Carbon black is another type of nanoparticle that may be present as an emulsion stabilizer in the compositions and methods disclosed herein. Various grades of carbon black will be familiar to one having ordinary skill in the art, any of which may be used herein. Other nanoparticles capable of absorbing infrared radiation may be used similarly.

Polymer nanoparticles are another type of nanoparticle that may be present as an emulsion stabilizer in the disclosure herein. Suitable polymer nanoparticles may include one or more polymers that are thermosetting and/or crosslinked, such that they do not melt when processed by melt emulsification according to the disclosure herein. High molecular weight thermoplastic polymers having high melting or decomposition points may similarly comprise suitable polymer nanoparticle emulsion stabilizers.

The nanoparticles may have an average diameter (D50 based on volume) of about <NUM> to about <NUM> (or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>).

The nanoparticles may have a BET surface area of about <NUM><NUM>/g to about <NUM><NUM>/g (or about <NUM><NUM>/g to about <NUM><NUM>/g, or about <NUM><NUM>/g to about <NUM><NUM>/g, or about <NUM><NUM>/g to about <NUM><NUM>/g, or about <NUM><NUM>/g to about <NUM><NUM>/g).

Nanoparticles may be included in the mixture <NUM> at a concentration of about <NUM> wt% to about <NUM> wt% (or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%)based on the weight of the thermoplastic polymer <NUM>.

Surfactants may be anionic, cationic, nonionic, or zwitterionic. Examples of surfactants include, but are not limited to, sodium dodecyl sulfate, sorbitan oleates, poly[dimethylsiloxane-co-[<NUM>-(<NUM>-(<NUM>-hydroxyethoxy)ethoxy)propylmethylsiloxane], docusate sodium (sodium <NUM>,<NUM>-bis(<NUM>-ethylhexoxy)-<NUM>,<NUM>-dioxobutane-<NUM>-sulfonate), and the like, and any combination thereof. Commercially available examples of surfactants include, but are not limited to, CALFAX® DB-<NUM> (sodium dodecyl diphenyl oxide disulfonate, available from Pilot Chemicals), SPAN® <NUM> (sorbitan maleate non-ionic surfactant), MERPOL® surfactants (available from Stepan Company), TERGITOL™ TMN-<NUM> (a water-soluble, nonionic surfactant, available from DOW), TRITON™ X-<NUM> (octyl phenol ethoxylate, available from SigmaAldrich), IGEPAL® CA-<NUM> (polyoxyethylene (<NUM>) isooctylphenyl ether, available from SigmaAldrich), BRIJ® S10 (polyethylene glycol octadecyl ether, available from SigmaAldrich), and the like, and any combination thereof.

Surfactants may be included in the mixture <NUM> at a concentration of about <NUM> wt% to about <NUM> wt% (or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%) based on the weight of the polyamide <NUM>. Alternatively, the mixture <NUM> may comprise no (or be absent of) surfactant.

A weight ratio of nanoparticles to surfactant may be about <NUM>:<NUM> to about <NUM>:<NUM> (or about <NUM>:<NUM> to about <NUM>:<NUM>, or about <NUM>:<NUM> to about <NUM>:<NUM>, or about <NUM>:<NUM> to about <NUM>:<NUM>).

As described above, the components <NUM>, <NUM>, and <NUM> can be added in any order and include mixing and/or heating during the process of combining <NUM> the components <NUM>, <NUM>, and <NUM>. For example, the emulsion stabilizer <NUM> may first be dispersed in the carrier fluid <NUM>, optionally with heating said dispersion, before adding the thermoplastic polymer <NUM>. In another nonlimiting example, the thermoplastic polymer <NUM> may be heated to produce a polymer melt to which the carrier fluid <NUM> and emulsion stabilizer <NUM> are added together or in either order. In yet another nonlimiting example, the thermoplastic polymer <NUM> and carrier fluid <NUM> can be mixed at a temperature greater than the melting point or softening temperature of the thermoplastic polymer <NUM> and at a shear rate sufficient enough to disperse the thermoplastic polymer melt in the carrier fluid <NUM>. Then, the emulsion stabilizer <NUM> can be added to form the mixture <NUM> and maintained at suitable process conditions for a set period of time.

Combining <NUM> the components <NUM>, <NUM>, and <NUM> in any combination can occur in a mixing apparatus used for the processing <NUM> and/or another suitable vessel. By way of nonlimiting example, the thermoplastic polymer <NUM> may be heated to a temperature greater than the melting point or softening temperature of the thermoplastic polymer <NUM> in the mixing apparatus used for the processing <NUM>, and the emulsion stabilizer <NUM> may be dispersed in the carrier fluid <NUM> in another vessel. Then, said dispersion may be added to the melt of the thermoplastic polymer <NUM> in the mixing apparatus used for the processing <NUM>.

The mixing apparatuses used for the processing <NUM> to produce the melt emulsion <NUM> should be capable of maintaining the melt emulsion <NUM> at a temperature greater than the melting point or softening temperature of the thermoplastic polymer <NUM> and applying a shear rate sufficient to disperse the polymer melt in the carrier fluid <NUM> as droplets.

Examples of mixing apparatuses used for the processing <NUM> to produce the melt emulsion <NUM> include, but are not limited to, extruders (e.g., continuous extruders, batch extruders, and the like), stirred reactors, blenders, reactors with inline homogenizer systems, and the like, and apparatuses derived therefrom.

Processing <NUM> and forming the melt emulsion <NUM> at suitable process conditions (e.g., temperature, shear rate, and the like) for a set period of time.

The temperature of processing <NUM> and forming the melt emulsion <NUM> should be a temperature greater than the melting point or softening temperature of the thermoplastic polymer <NUM> and less than the decomposition temperature of any components <NUM>, <NUM>, and <NUM> in the mixture <NUM>. For example, the temperature of processing <NUM> and forming the melt emulsion <NUM> may be about <NUM> to about <NUM> (or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>) greater than the melting point or softening temperature of the thermoplastic polymer <NUM> provided the temperature of processing <NUM> and forming the melt emulsion <NUM> is less than the decomposition temperature of any components <NUM>, <NUM>, and <NUM> in the mixture <NUM>.

The shear rate of processing <NUM> and forming the melt emulsion <NUM> should be sufficiently high to disperse the polymer melt in the carrier fluid <NUM> as droplets. Said droplets should comprise droplets having a diameter of about <NUM>,<NUM> or less (or about <NUM> to about <NUM>,<NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>,<NUM>).

The time for maintaining said temperature and shear rate for processing <NUM> and forming the melt emulsion <NUM> may be <NUM> seconds to <NUM> hours or longer (or <NUM> seconds to <NUM> minutes, or <NUM> minutes to <NUM> hour, or <NUM> minutes to <NUM> hours, or <NUM> hour to <NUM> hours, or <NUM> hours to <NUM> hours). Without being limited by theory, it is believed that a steady state of droplet sizes will be reached at which point processing <NUM> can be stopped. That time may depend on, among other things, the temperature, shear rate, thermoplastic polymer <NUM> composition, the carrier fluid <NUM> composition, and the emulsion stabilizer <NUM> composition.

The melt emulsion <NUM> may then be cooled <NUM>. Cooling <NUM> can be slow (e.g., allowing the melt emulsion to cool under ambient conditions) to fast (e.g., quenching). For example, the rate of cooling may range from about <NUM>/hour to about <NUM>/second to almost instantaneous with quenching (for example in dry ice) (or about <NUM>/hour to about <NUM>/hour, or about <NUM>/minute to about <NUM>/minute, or about <NUM>/minute to about <NUM>/minute, or about <NUM>/minute to about <NUM>/minute, or about <NUM>/second to about <NUM>/second, or about <NUM>/second to about <NUM>/second).

During cooling, little to no shear may be applied to the melt emulsion <NUM>. In some instances, the shear applied during heating may be applied during cooling.

The cooled mixture <NUM> resulting from cooling <NUM> the melt emulsion <NUM> comprises solidified thermoplastic polymer particles <NUM> (or simply thermoplastic polymer particles) and other components <NUM> (e.g., the carrier fluid <NUM>, excess emulsion stabilizer <NUM>, and the like). The thermoplastic polymer particles may be dispersed in the carrier fluid or settled in the carrier fluid.

The cooled mixture <NUM> may then be treated <NUM> to the separate thermoplastic polymer particles <NUM> (or simply thermoplastic polymer particles <NUM>) from the other components <NUM>. Suitable treatments include, but are not limited to, washing, filtering, centrifuging, decanting, and the like, and any combination thereof.

Solvents used for washing the thermoplastic polymer particles <NUM> should generally be (a) miscible with the carrier fluid <NUM> and (b) nonreactive (e.g., non-swelling and non-dissolving) with the thermoplastic polymer <NUM>. The choice of solvent will depend on, among other things, the composition of the carrier fluid and the composition of the thermoplastic polymer <NUM>.

Examples of solvents include, but are not limited to, hydrocarbon solvents (e.g., pentane, hexane, heptane, octane, cyclohexane, cyclopentane, decane, dodecane, tridecane, and tetradecane), aromatic hydrocarbon solvents (e.g., benzene, toluene, xylene, <NUM>-methyl naphthalene, and cresol), ether solvents (e.g., diethyl ether, tetrahydrofuran, diisopropyl ether, and dioxane), ketone solvents (e.g., acetone and methyl ethyl ketone), alcohol solvents (e.g., methanol, ethanol, isopropanol, and n-propanol), ester solvents (e.g., ethyl acetate, methyl acetate, butyl acetate, butyl propionate, and butyl butyrate), halogenated solvents (e.g., chloroform, bromoform, <NUM>,<NUM>-dichloromethane, <NUM>,<NUM>-dichloroethane, carbon tetrachloride, chlorobenzene, and hexafluoroisopropanol), water, and the like, and any combination thereof.

Solvent may be removed from the thermoplastic polymer particles <NUM> by drying using an appropriate method such as air drying, heat drying, reduced pressure drying, freeze drying, or a hybrid thereof. The heating may be performed preferably at a temperature lower than the glass transition point of the thermoplastic polymer (e.g., about <NUM> to about <NUM>).

The thermoplastic polymer particles <NUM> after separation from the other components <NUM> may optionally be further classified to produce purified thermoplastic polymer particles <NUM>. For example, to narrow the particle size distribution (or reduce the diameter span), the thermoplastic polymer particles <NUM> can be passed through a sieve having a pore size of about <NUM> to about <NUM> (or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>).

In another example of purification technique, the thermoplastic polymer particles <NUM> may be washed with water to remove surfactant while maintaining substantially all of the nanoparticles associated with the surface of the thermoplastic polymer particles <NUM>. In yet another example of purification technique, the thermoplastic polymer particles <NUM> may be blended with additives to achieve a desired final product. For clarity, because such additives are blended with the thermoplastic particles <NUM> or other particles resultant from the methods described herein after the particles are solidified, such additives are referred to herein as "external additives. " Examples of external additives include flow aids, other polymer particles, fillers, and the like, and any combination thereof.

In some instances, a surfactant used in making the thermoplastic polymer particles <NUM> may be unwanted in downstream applications. Accordingly, yet another example of purification technique may include at least substantial removal of the surfactant from the thermoplastic polymer particles <NUM> (e.g., by washing and/or pyrolysis).

The thermoplastic polymer particles <NUM> and/or purified thermoplastic polymer particles <NUM> (referred to as particles <NUM>/<NUM>) may be characterized by composition, physical structure, and the like.

As described above, the emulsion stabilizers are at the interface between the polymer melt and the carrier fluid. As a result, when the mixture is cooled, the emulsion stabilizers remain at, or in the vicinity of, said interface. Therefore, the structure of the particles <NUM>/<NUM>, in general, includes emulsion stabilizers (a) dispersed on an outer surface of the particles <NUM>/<NUM> and/or (b) embedded in an outer portion (e.g., outer <NUM> vol%) of the particles <NUM>/<NUM>.

Further, where voids form inside the polymer melt droplets, emulsion stabilizers <NUM> should generally be at (and/or embedded in) the interface between the interior of the void and the thermoplastic polymer. The voids generally do not contain the thermoplastic polymer. Rather, the voids may contain, for example, carrier fluid, air, or be void. The particles <NUM>/<NUM> may comprise carrier fluid at about <NUM> wt% or less (or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%) of the particles <NUM>/<NUM>.

The thermoplastic polymer <NUM> may be present in the particles <NUM>/<NUM> at about <NUM> wt% to about <NUM> wt% (or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%) of the particles <NUM>/<NUM>.

When included, the emulsion stabilizers <NUM> may be present in the particles <NUM>/<NUM> at about <NUM> wt% or less (or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%, or about <NUM> wt% to about <NUM> wt%) of the particles <NUM>/<NUM>. When purified to at least substantially remove surfactant or another emulsion stabilizer, the emulsion stabilizers <NUM> may be present in the particles <NUM> at less than <NUM> wt% (or <NUM> wt% to about <NUM> wt%, or <NUM> wt% to <NUM> wt%).

Upon forming thermoplastic particulates according to the disclosure herein, at least a portion of the nanoparticles, such as silica nanoparticles, may be disposed as a coating upon the outer surface of the thermoplastic particulates. At least a portion of the surfactant, if used, may be associated with the outer surface as well. The coating may be disposed substantially uniformly upon the outer surface. As used herein with respect to a coating, the term "substantially uniform" refers to even coating thickness in surface locations covered by the coating composition (e.g., nanoparticles and/or surfactant), particularly the entirety of the outer surface. The emulsion stabilizers <NUM> may form a coating that covers at least <NUM>% (or about <NUM>% to about <NUM>%, or about <NUM>% to about <NUM>%, or about <NUM>% to about <NUM>%, or about <NUM>% to about <NUM>%, or about <NUM>% to about <NUM>%, or about <NUM>% to about <NUM>%, or about <NUM>% to about <NUM>%) of the surface area of the particles <NUM>/<NUM>. When purified to at least substantially remove surfactant or another emulsion stabilizer, the emulsion stabilizers <NUM> may be present in the particles <NUM> at less than <NUM>% (or <NUM>% to about <NUM>%, or about <NUM>% to about <NUM>%, or about <NUM>% to about <NUM>%, or about <NUM>% to about <NUM>%, or about <NUM>% to about <NUM>%, or about <NUM>% to about <NUM>%, or about <NUM>% to about <NUM>%) of the surface area of the particles <NUM>. The coverage of the emulsion stabilizers <NUM> on an outer surface of the particles <NUM>/<NUM> may be determined using image analysis of the scanning electron microscope images (SEM micrographs). The emulsion stabilizers <NUM> may form a coating that covers at least <NUM>% (or about <NUM>% to about <NUM>%, or about <NUM>% to about <NUM>%, or about <NUM>% to about <NUM>%, or about <NUM>% to about <NUM>%, or about <NUM>% to about <NUM>%, or about <NUM>% to about <NUM>%, or about <NUM>% to about <NUM>%) of the surface area of the particles <NUM>/<NUM>. When purified to at least substantially remove surfactant or another emulsion stabilizer, the emulsion stabilizers <NUM> may be present in the particles <NUM> at less than <NUM>% (or <NUM>% to about <NUM>%, or about <NUM>% to about <NUM>%, or about <NUM>% to about <NUM>%, or about <NUM>% to about <NUM>%, or about <NUM>% to about <NUM>%, or about <NUM>% to about <NUM>%, or about <NUM>% to about <NUM>%) of the surface area of the particles <NUM>. The coverage of the emulsion stabilizers <NUM> on an outer surface of the particles <NUM>/<NUM> may be determined using image analysis of the SEM micrographs.

The particles <NUM>/<NUM> may have a D10 of about <NUM> to about <NUM> (or about <NUM> to about <NUM>, about <NUM> to about <NUM>, about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>), a D50 of about <NUM> to about <NUM> (or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>), and a D90 of about <NUM> to about <NUM> (or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>), wherein D10<D50<D90. The particles <NUM>/<NUM> may also have a diameter span of about <NUM> to about <NUM> (or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>). Without limitation, diameter span values of <NUM> or greater are considered broad, and diameter span values of <NUM> or less are considered narrow. For example, the particles <NUM>/<NUM> may have a D10 of about <NUM> to about <NUM>, a D50 of about <NUM> to about <NUM>, and a D90 of about <NUM> to about <NUM>, wherein D10<D50<D90.

The particles <NUM>/<NUM> may also have a diameter span of about <NUM> to about <NUM> (or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>).

In a first nonlimiting example, the particles <NUM>/<NUM> may have a D10 of about <NUM> to about <NUM>, a D50 of about <NUM> to about <NUM>, and a D90 of about <NUM> to about <NUM>, wherein D10<D50<D90.

In a second nonlimiting example, the particles <NUM>/<NUM> may have a D10 of about <NUM> to about <NUM>, a D50 of about <NUM> to about <NUM>, and a D90 of about <NUM> to about <NUM>, wherein D10<D50<D90.

In a third nonlimiting example, the particles <NUM>/<NUM> may have a D10 of about <NUM> to about <NUM>, a D50 of about <NUM> to about <NUM>, and a D90 of about <NUM> to about <NUM>, wherein D10<D50<D90. Said particles <NUM>/<NUM> may have a diameter span of about <NUM> to about <NUM>.

In a fourth nonlimiting example, the particles <NUM>/<NUM> may have a D10 of about <NUM> to about <NUM>, a D50 of about <NUM> to about <NUM>, and a D90 of about <NUM> to about <NUM>, wherein D10<D50<D90. Said particles <NUM>/<NUM> may have a diameter span of about <NUM> to about <NUM>.

In a fifth nonlimiting example, the particles <NUM>/<NUM> may have a D10 of about <NUM> to about <NUM>, a D50 of about <NUM> to about <NUM>, and a D90 of about <NUM> to about <NUM>, wherein D10<D50<D90. Said particles <NUM>/<NUM> may have a diameter span of about <NUM> to about <NUM>.

The particles <NUM>/<NUM> may have a circularity of about <NUM> or greater (or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to <NUM>).

The particles <NUM>/<NUM> may have an angle of repose of about <NUM>° to about <NUM>° (or about <NUM>° to about <NUM>°, or about <NUM>° to about <NUM>°, or about <NUM>° to about <NUM>°).

The particles <NUM>/<NUM> may have a Hausner ratio of about <NUM> to about <NUM> (or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>).

The particles <NUM>/<NUM> may have a bulk density of about <NUM>/cm<NUM> to about <NUM>/cm<NUM> (or about <NUM>/cm<NUM> to about <NUM>/cm<NUM>, or about <NUM>/cm<NUM> to about <NUM>/cm<NUM>, or about <NUM>/cm<NUM> to about <NUM>/cm<NUM>, or about <NUM>/cm<NUM> to about <NUM>/cm<NUM>).

Depending on the temperature and shear rate of processing <NUM> and the composition and relative concentrations of the components <NUM>, <NUM>, and <NUM>, different shapes of the structures that compose the particles <NUM>/<NUM> have been observed. Typically, the particles <NUM>/<NUM> comprise substantially of spherical particles (having a circularity of about <NUM> or greater). However, other structures that included disc and elongated structures have been observed in the particles <NUM>/<NUM>. Therefore, the particles <NUM>/<NUM> may comprise one or more of: (a) substantially spherical particles having a circularity of <NUM> or greater, (b) disc structures having an aspect ratio of about <NUM> to about <NUM>, and (c) elongated structures having an aspect ratio of <NUM> or greater. Each of the (a), (b), and (c) structures have emulsion stabilizers dispersed on an outer surface of the (a), (b), and (c) structures and/or embedded in an outer portion of the (a), (b), and (c) structures. At least some of the (a), (b), and (c) structures may be agglomerated. For example, the (c) elongated structures may be laying on the surface of the (a) substantially spherical particles.

The particles <NUM>/<NUM> may have a sintering window that is within <NUM>, preferably within <NUM>, of the sintering window of the thermoplastic polymer <NUM> (comprising one or more OAMB-polyamides and optionally one or more other thermoplastic polymers).

The OAMB-polyamide particles described herein may be used to produce a variety of objects (or articles). The OAMB-polyamides described herein may be used alone or in combination with other particles comprising other thermoplastic polymers (e.g., polyamides without an optical absorber and/or other thermoplastic polymers). Examples of thermoplastic polymers that may be used in such other particles include, but are not limited to, polyamides, polyurethanes, polyethylenes, polypropylenes, polyacetals, polycarbonates, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polytrimethylene terephthalate (PTT), polyhexamethylene terephthalate, polystyrenes, polyvinyl chlorides, polytetrafluoroethenes, polyesters (e.g., polylactic acid), polyethers, polyether sulfones, polyetherether ketones, polyacrylates, polymethacrylates, polyimides, acrylonitrile butadiene styrene (ABS), polyphenylene sulfides, vinyl polymers, polyarylene ethers, polyarylene sulfides, polysulfones, polyether ketones, polyamide-imides, polyetherimides, polyetheresters, copolymers comprising a polyether block and a polyamide block (PEBA or polyether block amide), grafted or ungrafted thermoplastic polyolefins, functionalized or nonfunctionalized ethylene/vinyl monomer polymer, functionalized or nonfunctionalized ethylene/alkyl (meth)acrylates, functionalized or nonfunctionalized (meth)acrylic acid polymers, functionalized or nonfunctionalized ethylene/vinyl monomer/alkyl (meth)acrylate terpolymers, ethylene/vinyl monomer/carbonyl terpolymers, ethylene/alkyl (meth)acrylate/carbonyl terpolymers, methylmethacrylate-butadiene-styrene (MBS)-type core-shell polymers, polystyrene-block-polybutadiene-block-poly(methyl methacrylate) (SBM) block terpolymers, chlorinated or chlorosulphonated polyethylenes, polyvinylidene fluoride (PVDF), phenolic resins, poly(ethylene/vinyl acetate)s, polybutadienes, polyisoprenes, styrenic block copolymers, polyacrylonitriles, silicones, and the like, and any combination thereof. Copolymers comprising one or more of the foregoing may also be used in the methods and systems described herein.

The OAMB-polyamide particles may be useful in applications that include, but are not limited to, paints, powder coatings, ink jet materials, electrophotographic toners, <NUM>-D printing, and the like.

By way of nonlimiting example, <NUM>-D printing processes of the present disclosure may comprise: depositing OAMB-polyamide particles in the present disclosure (and optionally one or more other thermoplastic polymers and/or one or more compatibilizers) optionally in combination with other particles comprising one or more thermoplastic polymers and/or one or more compatibilizers upon a surface in a specified shape, and once deposited, heating at least a portion of the particles to promote consolidation thereof and form a consolidated body (or object or article), such that the consolidated body has a void percentage of about <NUM>% or less after being consolidated. For example, heating and consolidation of the thermoplastic polymer particles may take place in a <NUM>-D printing apparatus employing a laser, such that heating and consolidation take place by selective laser sintering.

Examples of articles that may be produced by such methods where the OAMB-polyamide may be all or a portion of said articles include, but are not limited to, particles, films, packaging, toys, household goods, automotive parts, aerospace/aircraft-related parts, containers (e.g., for food, beverages, cosmetics, personal care compositions, medicine, and the like), shoe soles, furniture parts, decorative home goods, plastic gears, screws, nuts, bolts, cable ties, jewelry, art, sculpture, medical items, prosthetics, orthopedic implants, production of artifacts that aid learning in education, <NUM>-D anatomy models to aid in surgeries, robotics, biomedical devices (orthotics), home appliances, dentistry, electronics, sporting goods, and the like.

The OAMB-polyamides described herein may have a specific chemical fingerprint that is useful in identifying objects, tracking objects, authenticating objects, and/or determining the health of objects. Further, the placement of where the OAMB-polyamides are located in the objects is another layer of fingerprinting the objects for identifying objects, tracking objects, authenticating objects, and/or determining the health of objects.

Methods of identifying objects, tracking objects, authenticating objects, and/or determining the health of objects may include (a) exposing the object comprising OAMB-polyamides to electromagnetic radiation (e.g., for fluorophores preferably at a wavelength of <NUM> or less or <NUM> or greater); (b) sensing one or more spectra related to the electromagnetic radiation absorbed and/or reemitted (e.g., for fluorophores preferably the photoluminescence emitted between <NUM> to <NUM>); and (c) comparing the spectra to the known spectra for the optical absorbers used in said object or portion thereof. Optionally, the location of where the spectra area is located on the object may be compared to the known location where the spectra area should be. The comparison(s) can be used for identifying and/or authenticating the object. For tracking, the comparison(s) may be done and/or the detected spectra and/or spectra area may be logged into a database along with the physical location of the object. Further, the health of objects that wear and/or crack can be ascertained. For example, a core portion of the article may comprise optical absorbers and an outer portion may cover the core portion and not comprise the optical absorbers (or comprise different optical absorbers). Then, when comparing spectra, the appearance of spectral features for the optical absorbers in the core may indicate that the object is at or near the end of life.

The emulsion stabilizer may be present in the mixture at <NUM> wt% to <NUM> wt% by weight of the OAMB-polyamide. The OACTP particles may have a diameter span of about <NUM> to about <NUM>.

While compositions and methods are described herein in terms of "comprising" various components or steps, the compositions and methods can also "consist essentially of" or "consist of" the various components and steps.

To facilitate a better understanding of the embodiments of the present invention, the following examples of preferred or representative embodiments are given.

Prophetic Example <NUM> -Preparation of Modified-Alizarin. About <NUM> mmol DMAP was added to a stirred solution of about <NUM> mmol bromoacetate in DMSO. The mixture was stirred at room temperature for <NUM> minutes before adding <NUM> mmol DCC. After <NUM> minutes, <NUM> mmol alizarin was added and stirred for <NUM> hours. The organic layer was separated, mixed with ethyl acetate, washed with water, and dried over Na<NUM>SO<NUM>. After evaporation of the solvent, the crude residue was purified by column chromatography using cyclohexane-EtOAc (<NUM>:<NUM>) as an eluent.

<NUM> DMSO and <NUM> mmol nylon polymer were mixed. To the mixture, <NUM> mmol potassium t-butoxide was added. The mixture was blanketed with argon and heated to a temperature of <NUM>. The suspension was allowed to mix at <NUM> for about <NUM> hour or until most of nylon was dissolved. Next, <NUM> mmol modified alizarin was added to the flask, and the reaction was allowed to proceed overnight. The next day the reaction mixture was cooled to room temperature and precipitated into <NUM> of deionized water. The mixture comprising alizarin-modified nylon, unmodified nylon, and unreacted modified-alizarin was then isolated by filtration and repeatedly washed with water to remove the DMSO solvent. Next, the solid was rinsed with methanol to remove the water then stirred in hexanes to remove the unreacted modified-alizarin. The resulted nylon mixture (modified and unmodified) was then isolated by filtration and allowed to dry in a vacuum oven at <NUM> overnight.

Claim 1:
A method comprising:
esterifying a hydroxyl-pendent optical absorber with a halogen-terminal aliphatic acid to yield a halogen-terminal alkyl-optical absorber; and
N-alkylating a polyamide with the halogen-terminal alkyl-optical absorber to yield a polyamide having an optical absorber pendent from the polyamide's backbone (OAMB-polyamide),
wherein the optical absorber absorbs ultraviolet or visible light.