Hydrogenation of polymers in the presence of supercritical carbon dioxide

A method of hydrogenating a polymer, comprising the steps of:

• (a) providing a liquid dense phase, said dense phase consisting essentially of a polymer in an organic solvent, said polymer selected from the group consisting of polystyrene, poly(bisphenol A carbonate), poly(ethylene terephthalate), polybutadiene and copolymers thereof, and polyisoprene and copolymers thereof, with said solvent included in said dense phase in an amount of from 0.1 to 20 weight percent;
• (b) providing a solid catalyst system, said catalyst system comprising at least one metal hydrogenation catalyst selected from the group consisting of nickel and ruthenium immobilized on a solid support;
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• (c) providing a light phase, said light phase consisting essentially of hydrogen at a pressure of 100 to 2000 psi and supercritical carbon dioxide;
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• (d) contacting said dense phase, said light phase and said catalyst system at a temperature of 50 to 300° C., and in an amount of 0.1 to 1 weight of catalyst system per weight of polymer, to react said hydrogen with said polymer and said polymer is hydrogenated.