Tunable block copolymers based on a polysiloxane backbone by anionic ring-opening polymerization

Block copolymers with tunable functional groups were obtained through the postfunctionalization of poly(dimethylsiloxane)-b-poly(methylvinylsiloxane) diblock copolymers prepared by the anionic ring-opening polymerization of cyclotrisiloxanes. As the source of the vinyl-containing segment, 1,3,5-trimethyl-1,3,5-trivinyleyelotrisiloxane was used. The obtained polymers showed high block purity and a narrow molecular weight distribution. The postmodification was carried out with a two-step procedure: in the first step, epoxide groups were introduced into the diblock copolymer, and in the second step, the ring opening of the latter functionalities was carried out. A variety of different nucleophiles were used for the ring-opening reaction, and the influence of selected reaction parameters, such as the dilution and the use of monofunctional and difunctional nucleophiles, on the resulting polymers were investigated. (C) 2004 Wiley Periodicals, Inc.