Radical grafted carbonyl containing compounds and preparation

Abstract: Novel carbonyl containing compositions are described, which may be prepared by contacting, in the presence of a free radical initiator, a first compound from saturated hydrocarbons, substituted saturated hydrocarbons, polymers and mixtures thereof with a carbonyl containing compound or mixtures thereof having the structure: where X and Y are independently selected from OH, OR₁, NR₁R₂ and R₁ wherein R₁ and R₂ are selected independently from aryl radicals or alkyl radicals of from 1 to 18 carbon atoms.

Description: In U.S. Patent 5,057,564, cyclic carbonyl containing compounds are disclosed. These compounds are produced by heating a mixture of a carbonyl compound having an ene reactive carbonyl group with an unsaturated polymer. Although the process and products are quite useful, it nonetheless would be desirable to be able to form carbonyl modified compounds of saturated hydrocarbons, especially saturated polymers. According to one aspect of the present invention, a method of forming a carbonyl containing composition comprises contacting, in the presence of a free radical initiator, (i) at least one compound selected from saturated hydrocarbons; substituted saturated hydrocarbons; saturated hydrocarbon polymers; and mixtures thereof; with (ii) one or more carbonyl containing compounds having the structure: where X and Y are independently selected from OH, OR 1 , NR 1 R 2 and R 1 wherein R 1 and R 2 are selected independently from the group consisting of aryl radicals or alkyl radicals of from 1 to 8 carbon atoms. In general, the contacting is conducted at a temperature and for a time sufficient to produce the compositions. Preferably the contacting is conducted at about the decomposition temperature of the radical initiator. Suitably, the temperature can be in the range 90°C to 200°C. Reaction times of from 0.05 to 1 hour are typical. According to another aspect, the present invention provides a composition of matter comprising (a) a hydrocarbon radical selected from saturated hydrocarbon, substituted saturated hydrocarbon, saturated hydrocarbon polymer radicals and mixtures thereof, and (b) a carboxyl radical having the formula and wherein X and Y are independently selected from OH, OR 1 , NR 1 R 2 and R 1 wherein R 1 and R 2 are aryl or alkyl of from 1 to 18 carbon atoms for producing the reaction product of (a) and (b). The hydrocarbon radical may be, for example, a said hydrocarbon and having 10 to 50 carbon atoms; a said polymer material and having a Mn of 500 to 10 million; or a said substituted hydrocarbon. The carboxyl moiety preferably derives from diethyl ketomalonate. The compositions of, and prepared by the method of, the invention are particularly useful as solution viscosification agents. The radical-initiated reaction of carbonyl monomers can be applied to a wide spectrum of hydrocarbons which can be selected from the group consisting of normal alkanes such as decane, hexadecane, octadecane, tricosane, paraffins having 10 to 50 carbon atoms; branched alkanes such as dimethyl hexane, trimethyldecane, tetra-methylpentadecane [pristane]; white oils, Nujols, hydrogenated oligomers and co-oligomers of ethylene, propylene, butylene and higher molecular weight olefin oligomers having 10 to about 50 carbons; substituted hydrocarbons consisting of normal and branched alkanes having one or more functional groups such as OH, O[CH 2 CH 2 O] x H, [x=1-10], Cl, CN, COOH, COOalkyl, C[=0]alkyl. [alkyl contains 1-18 carbons], and aryl. Typical examples of useful substituted hydrocarbons consist of decanol, octadecanol, ethoxylated octadecanol, stearic acid, ethyl stearate, methyl decyl ketone, tetrapropylbenzene, tetrapropylene, tetraisobutylene, mineral oils, and synthetic lubricant oils. Useful polymers include but are not limited to polymers derived from one or more of the following monomers: ethylene, propylene, butenes, higher alpha-olefins, styrene, allyl esters, vinyl esters, and halides such as vinyl acetate and vinyl chloride; acrylic acid, acrylonitrile, and the like. Polymers can be linear or branched, and high or low molecular weight [Mn=500 to 10 million]. Homopolymers of ethylene such as high and low density polyethylene, atactic or crystalline polypropylene, polybutene, polyisobutylene homopolymers and copolymers of higher alpha-olefins, copolymers of ethylene with propylene, EPR, which may also contain unconjugated dienes [EPDM], copolymers of ethylene with butenes or higher alpha-olefins, copolymers of propylene with butenes, and higher alpha-olefins. When dienes such as butadiene or isoprene are used in copolymer formation, the resulting polymers are hydrogenated to saturate substantially all of the ethylenic unsaturation. Useful polymers include hydrogenated styrene butadiene block, and tapered copolymers and hydrogenated styrene butadiene block. Since ethylenic unsaturation in polymers sometimes induces undesirable crosslinking during radical grafting, excess olefinic groups should be removed by catalytic hydrogenation. Typical carbonyl compounds include ketomalonic acid, and esters of ketomalonic acid including alkyl and aryl esters. Other useful keto acids include alpha-ketosuccinic acid, diketosuccinic acid, and any alpha ketohydrocarboic acid, and alpha, beta-diketohydrocarboic acid and their ester and amide derivatives. Useful ketone monomers include dimethyl, diphenyl, and ditolyl tri-ketones and tetra-ketones. Useful free radical initiators used in forming the compounds of this invention include dialkyl peroxides such as di-tertiary-butyl peroxide,2,5-dimethyl-2,5-di-tertiary-butyl-peroxyhexane, di-cumyl peroxide; alkyl peroxides such as tertiary-butyl hydroperoxide, tertiary-octyl hydroperoxide, cumene hydroperoxide; aroyl peroxides such as benzoyl peroxide; peroxy esters such as tertiary-butyl peroxypivalate, tertiary-butyl perbenzoate; and azo compounds such as azo-bis-isobutyronitrile. Any free radical initiator with a suitable half life at the reaction temperatures cited above can be used. When radical grafting in solution, the polymer is dissolved in a suitable solvent such as chlorobenzene, dichlorobenzene, or mineral oil, and heated to temperatures ranging from 90°C to 200°C depending upon the nature of the free radical initiator being used. The initiator can be added in one dose or dropwise over a suitable time span, usually from 5 to 60 minutes. Another option is to add a mixture of the monomer and peroxide in a suitable solvent to the hydrocarbon, or polymer solution at an addition rate and temperature consistent with the half-life of the radical initiator. The reaction mixture is heated with stirring until infrared and/or nmr analysis indicates that radical addition of the carbonyl monomer to the hydrocarbon or polymer is complete. Depending upon temperature and concentration, reaction times of 0.1 to 12 hours are usually sufficient to achieve high levels of monomer utilization. When necessary, radical adducts can be isolated by solvent removal using evaporative techniques, or in the case of polymers, by adding the reaction mixture to a polar solvent such as methanol, or acetone which tend to precipitate the radically functionalized polymer. Radical grafting of polymers may also be conducted without a solvent, as in a melt, or in polymer processing equipment such as a rubber mill, an extruder, a Banbury mixer, and Brabender mixer. When radical grafting is conducted in bulk, reaction temperatures ranging from 90°C to 220°C, and reaction times ranging from .05 to 1 hour are typical. In general, the amount of carbonyl compound employed is dictated by the level of functionality desired in the resultant product. Levels of radical grafting onto hydrocarbons and polymers ranging from 0.1 wt.% to 20 wt.% carbonyl monomer can readily be achieved. If desired, higher levels of functionality can be realized by using additional monomer and free radical initiator. A typical reaction is illustrated by the following equation: wherein X and Y have the values previously described, RH represents a suitable saturated hydrocarbon, and I represents the free radical initiator. The amount of free radical initiator used is generally between 1 and 100 wt.% based on the weight of the carbonyl compound, and often depends upon the nature of the free radical initiator, and hydrocarbon or polymer substrate being grafted. The susceptibility of certain polymers to undergo crosslinking and/or chain scission requires careful discretion regarding reagent concentrations, time, temperature, and process conditions since these parameters are all dependent variables in the grafting process. Ordinarily, grafting processes which use from 10 wt.% to 50 wt.% levels of free radical initiator, at grafting temperatures ranging from 90°C to 180°C, in an oxygen-free reactor can produce functional polymers with significant levels of appended carbonyl monomers. EXAMPLES Example 1 A tenth mole (26.8 grams) of 2,6,10,14-tetramethylpentadecane (pristane), and 0.01 mole (1.74 grams) of diethyl ketomalonate were combined and stirred in a nitrogen blanketed reactor equipped with reflux condensor, thermometer, and an addition funnel. The stirred mixture was heated to about 150°C and treated with several drops of t-butyl peroxide, a radical initiator. The reaction temperature spontaneously rose from 155° to 160°C in a few minutes. The peroxide was again added dropwise at a rate of about 1 drop per minute. When the peroxide addition was complete (1 ml added), the reaction temperature was increased to 175°C, and kept at 175°C for two hours. Vacuum distillation of the reaction mixture gave a residue which featured an infrared spectrum with an intense ester carbonyl absorption band at 5.85 microns, and a gc-mass spectrum consisting of several isomers with a molecular ion (m/e=432), which is indicative of a carbonyl modified pristane. Example 2 Ten grams of methyl nonanoate and 1 gram of diethyl ketomalonate were combined in a nitrogen-blanketed reactor, and heated to about 170°C. One ml of t-butyl peroxide was added in one dose, and the reaction mixture was stirred at 180°C for about 2.5 hours. Another ml of t-butyl peroxide was then added in one dose, and the stirred mixture was heated at 170°C for about 7 hours. Evaporation of the mixture gave a residue which featured an infrared spectrum with a characteristic ester carbonyl absorption band at about 5.8 microns, and a gc-mass spectrum with peaks ascribable to isomeric radical adducts of diethyl ketomalonate and methyl nonanoate. Example 3 Ten grams of polyisobutylene (Mn=950) and 1.5 ml of diethyl ketomalonate were combined in a nitrogen blanketed reactor and heated to 160°C. One ml of t-butyl peroxide was added in one dose to the stirred solution which was heated at 160°C for about 8 hours. Roto-evaporation gave a residue featuring an infrared spectrum with a strong ester carbonyl absorption band at about 5.8 microns. Elemental analysis indicated that the functionalized polymer contained 1.92% oxygen. Example 4 Ten grams of ethylene-propylene copolymer (containing 55 wt.% propylene, and having an Mn=54,000), one gram of diethyl ketomalonate and 90 grams of 1,2-dichlorobenzene were combined in a nitrogen blanketed reactor and heated to about 150°C. One ml of radical initiator, t-butyl peroxide, was added dropwise over a half hour period, and the solution was stirred at 160°C for about 8 hours. Another ml of t-butyl peroxide was added and the reaction mixture was stirred at 160°C for about 12 hours. The solution was added to a liter of acetone to precipitate the functionalized polymer, which was then dissolved in cyclohexane, and again precipitated in a large volume of acetone. The dried polymer featured an infrared spectrum with a prominent ester carbonyl absorption band at 5.85 microns, and analyzed for 3.76% oxygen.

Claims: A method of forming a carbonyl containing composition, comprising contacting, in the presence of a free radical initiator, (i) at least one compound selected from saturated hydrocarbons; substituted saturated hydrocarbons; saturated hydrocarbon polymers; and mixtures thereof; with (ii) one or more carbonyl containing compounds having the structure: wherein X and Y are independently selected from OH, OR 1 , NR 1 R 2 and R 1 wherein R 1 and R 2 are aryl radicals or alkyl radicals of from 1 to 18 carbon atoms. The method of claim 1, wherein said contacting is at a temperature of from 90°C to 200°C. The method of claim 1 or claim 2, wherein said hydrocarbon has from 10 to 50 carbon atoms. A method of any one of claims 1 to 3, wherein the substituent group of the substituted hydrocarbon is selected from OH, O[CH 2 CH 2 O] x H, where x is 1 to 10, Cl, CN, COOH, COOalkyl and C[=0]alkyl, where the alkyl has 1 to 18 carbon atoms, and aryl. The method of claim 1 or claim 2, wherein said polymer has a Mn of from 500 to 10 million. The method of any one of claims 1, 2 or 5, wherein the hydrocarbon polymer is derived from one or more of ethylene, propylene, butenes, higher alpha-olefins, styrene, allyl esters, vinyl esters, vinyl halides, acrylic acid and acrylonitrile. The method of any preceding claim, wherein the carbonyl containing compound is an alkyl ester of ketomalonic acid. A composition of matter comprising (a) a hydrocarbon radical selected from saturated hydrocarbon, substituted saturated hydrocarbon, saturated hydrocarbon polymer radicals and mixtures thereof, and (b) a carboxyl radical having the formula wherein X and Y are independently selected from OH, OR 1 , NR 1 R 2 and R 1 wherein R 1 and R 2 are aryl radicals or alkyl radicals of from 1 to 18 carbon atoms, for producing the reaction product of (a) and (b). The composition of claim 8, wherein the hydrocarbon radical is a saturated hydrocarbon and has from 10 to 50 carbon atoms. The composition of claim 8, wherein the hydrocarbon radical is polymeric and has a Mn of from 500 to 10 million. The composition of claims 8 or 9, wherein the substituent or functional group is selected from OH, O[OH 2 CH 2 O] x H, where x is 1 to 10; Cl; CN; COOH; COOalkyl and C[=0]alkyl, where the alkyl has 1 to 18 carbon atoms, and aryl. The composition of claims 8 or 10 wherein the hydrocarbon polymer is derived from one or more of ethylene, propylene, butenes, higher alpha olefins, styrene, allyl esters, vinyl esters, vinyl halides, acrylic acid and acrylonitrite. The composition of any one of claims 8 to 12 wherein the carboxyl moiety derives from diethyl ketomalonate.

Inventors: BROIS STANLEY JAMES, OGLETREE JACQUELINE, BROIS, STANLEY JAMES, OGLETREE, JACQUELINE
Applicants: EXXON RESEARCH ENGINEERING CO, EXXON RESEARCH AND ENGINEERING COMPANY
Application year: 1993
Main classification: C08F8
IPC codes: C08F8, C07C59, C07C69, C07C233, C07C51, C07C67