Hydrogenation process for unsaturated homo and copolymers
AssigneeExxon Research & Engineering Co.
InventorsChristine A. Costello, Pamela J. Wright, Donald N. Schulz, Joseph A. Sissano
Life of this patent
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Abstract
It has now been discovered that the hydrogenation of unsaturated homo and copolymers can be effectively carried out in the absence of added gaseous hydrogen by contacting the unsaturated polymer with a hydrogen donor compound in the presence of a Group VIII metal catalyst, especially a supported palladium catalyst, for a time and at a temperature sufficient to bring about the hydrogenation of the unsaturated polymer.
Claims12
A method for hydrogenating olefinic double bonds in unsaturated homo and copolymers comprising:
- contacting an unsaturated polymer having olefinic double bonds with a hydrogen donor compound in the presence of a Group VIII metal catalyst for a time and at a temperature sufficient to hydrogenate at least some of the olefinic double bonds in the polymer.
A method for hydrogenating olefinic double bonds in unsaturated polymers in the absence of added gaseous hydrogen and without substantial molecular weight degradation or gelation of the unsaturated polymer comprising:
- dissolving a polymer having olefinic double bonds in a solvent, the polymer being selected from the group consisting of 1,2- and 1,4-polybutadiene, 1,4- and 3,4-polyisoprene, copolymers of butadiene and isoprene with vinyl aromatic monomers, acrylonitrile and acrylates and the solvent being selected from the group consisting of hexane, toluene, cyclohexane, tetrahydrofuran and mixtures of the foregoing with an alcohol having the formula CH.sub.3 (CH.sub.2).sub.n OH and R--OH where n is from 1 to about 17 and R is a tertiary alkyl group having from about 4 to about 16 carbon atoms, thereby forming a polymer solution;
- adding to the polymer solution a supported palladium catalyst and a hydrogen donor compound selected from the group consisting of formic acid, formates, phosphoric acid, phosphonates, cyclohexene and indoline, the ratio of hydrogen donor compound to olefinic double bonds being in the range of from about 1 to about 100, thereby forming a heterogeneous mixture;
- heating the mixture at a temperature in the range of from about 30.degree. C. to about 110.degree. C. for about 0.5 to about 24 hours whereby the olefinic double bonds are hydrogenated without substantial degradation or gelation of the polymer.
Dependencies are inferred from the claim text.