Bifunctional anionic initiators: A critical study and overview

Abstract

Abstract The suitability of several dilithio compounds as initiators for the anionic polymerization of dienes was tested in view of the following criteria: quantitative reaction of diolefins with sec ‐butyllithium within reasonable periods of time, precipitation of dilithio compounds in a heptane/toluene mixture, sufficient solubility of the dilithio compounds in toluene, rapid initiation of polymerization and small dispersion index of the polymer, low cost of the preparation of the diolefins and the dilithio initiators. The results show that with respect to the diolefins investigated the bifunctional initiator derived from 1,4‐bis(4‐(1‐phenylvinyl)phenyl)‐butane is most suited for the preparation of diene blocks in ABA‐triblock copolymers.