Selective hydrogenation of conjugation diolefin polymers with rare earth catalysts

Abstract

This invention provides a catalyst and a process for the hydrogenation of conjugated diolefin polymers which first involves the polymerization or copolymerization of such monomers with an organo alkali metal polymerization initiator in a suitable solvent thereby creating a living polymer. The living polymer can be terminated by the addition of hydrogen. Finally, selective hydrogenation of the unsaturable double bonds in the conjugated diolefin units of the terminated polymer is carried out in the presence of an initiator and at least one rare earth compound of the formula *Cp.sub. MR where *Cp is pentamethylcyclopentadiene, M is a rare earth element and R is alkyl, aryl, aralkyl or hydrogen.

Dependencies are inferred from the claim text.