Specificity of initiating systems based on allyl derivatives of group VI-metals in the formation of graft and block copolymers

Abstract

Polyvinylpyridines activated by tris(x-allyl)chromium and by tetrakis (a-allyl)molybdenum or tetrakis(a-allyl)tungsten, complexed with tetrahydrofuran, were used for grafting with acrylonitrile. The products obtained, differing in the degree of branching, were characterized by various physical methods. Block copolymers of the types butadiene-acrylonitrile and styrene-oligobutadiene-acrylonitrile were synthesized by the use of tris(n-butadienyl)chromium as the initial active agent. Some molecular parameters of these block copolymers were established.