Amphiphilic Linear-Hyperbranched Block Copolymers with Linear Poly(ethylene oxide) and Hyperbranched Poly(carbosilane) Block

Abstract

The synthesis of amphiphilic linear-hyperbranched block copolymers with a linear poly(ethylene oxide) (PEO) segment and a hyperbranched poly(carbosilane)s (PCS) block in a rapid three-step strategy is described, combining oxyanionic polymerization with carbosilane chemistry. A linear precursor block copolymer was synthesized via anionic polymerization of allyl glycidyl ether onto a commercial hydroxyl-terminated PEO, using its cesium alkoxide as macro-initiator. The resulting linear AB or ABA-type di- or triblock copolymers serve as polymer cores for the subsequent hydrosilylation polyaddition of an AB2-type carbosilane monomer. Di(allyl)methylsilane or methyldi(undec-10-enylsilane) were employed, using Karstedt’s catalyst as Pt0-species. Due to the high reactivity of allyloxy groups in catalytic hydrosilylation reactions, the slow monomer addition technique, previously used for the controlled polyaddition of AB2-monomers, was not necessary in this case and complete conversion of all core allyl groups is ...