Star-shaped polydimethylsiloxane block copolymers and process for the preparation thereof

摘要

A star block copolymer comprised of vinyl aromatic hydrocarbon and/or conjugated diene polymer arms and polydimethylsiloxane arms radiating outwardly from a polyalkenyl aromatic coupling agent core is produced by first anionically polymerizing a vinyl aromatic hydrocarbon and/or a conjugated diene to produce living polymer arms, reacting the living polymer arms with a polyalkenyl aromatic coupling agent to couple the arms thereto, polymerizing this coupled product with hexa-methylcyclotrisiloxane in the presence of a polar promoter and then terminating the polymerization.