Synthesis of telechelic polymers through radical polymerization with a two-component iniferter system

Abstract

A two-component iniferter system, consisting of an initiator and a chain transfer agent bearing the same functional group, is proposed for control of the chain-end structure of vinyl polymers. In this paper, 4,4′-azobiscyanovaleric acid (ACVA) and dithiodiglycol acid (DDGA) were used as initiator and chain transfer agent respectively, for polymerizations of some vinyl monomers to synthesize the polymers having a carboxyl group at both chain-ends. In the polymerizations of styrene (St) and vinyl acetate, the proposed two-component iniferter system was found to be effective for the synthesis of the telechelic polymers. On the other hand, the end-structure of the polymers could not be controlled efficiently in polymerizations of butadiene, methyl acrylate and methyl methacrylate; diisopropyl fumarate gave telechelic polymers with ACVA and DDGA. Polycondensation of the resulting telechelic poly(St) with polyethyleneglycol was carried out to obtain a block copolymer.