Epoxidized solid elastomeric copolymers

Abstract

An epoxidized linear block copolymer which prior to epoxidation comprises at least one triblock I--B--I, wherein I is a block of a polymerized conjugated diene of at least 5 carbon atoms, such as isoprene, and B is a block of a polymer of a conjugated diene, different from that polymerized to form the I blocks, of at least 4 carbon atoms, such as 1,3-butadiene. The B block may be selectively hydrogenated before or after epoxidation so that they contain substantially no ethylenic unsaturation, while the epoxidation reaction forms epoxy groups from double bonds in the I blocks. Also disclosed is an alternative epoxidized solid linear block copolymer which prior to epoxidation contains at least one triblock wherein the first polymer block is a copolymer of an aryl-substituted olefin, such as styrene, and the conjugated diene used to polymerize the block I, the second or middle block is a polymer of the diene used to polymerize the block B, and the third polymer block is the same as the first polymer block. In this alternative copolymer, the middle block may also be selectively hydrogenated, so that it contains substantially no ethylenic unsaturation while the epoxidation reaction forms epoxy groups from double bonds in the first and third blocks. The disclosure also includes epoxidized solid linear random copolymers and solid star-branched block and random copolymers made from the same monomers as the linear block copolymers, and methods for producing the foregoing epoxidized polymers.