Abstract: A graft copolymer of a syndiotactic styrene contains polar functional grafting arms. Due to the presence of polar grafting arms, the compatibility of the graft copolymer is substantially improved over the original syndiotactic styrene. Moreover, the graft copolymer can serve as a compatibilizer for a polymer blend so as to improve the compatibility of the polymer blend with other polymers, and increase the impact resistance and elongation of the polymer blend, while the physical properties of the original polymers in the polymer blend can still be maintained.

Abstract: The present invention provides a process for selective hydrogenation of a conjugated diene polymer. The process includes bringing the conjugated diene polymer in an inert organic solvent into contact with hydrogen in the presence of a specific hydrogenation catalyst combination including (A) a substituted or unsubstituted bis(cyclopentadienyl) Group VIII transition metal compound and (B) an organic lithium compound. The hydrogenation can be carried out in the presence of a small amount of the hydrogenation catalyst combination under mild conditions, and both the hydrogenation conversion and selectivity to conjugated diene units are high.