Block Copolymers By Transformation Of Living Cationic Polymerization Into Radical Polymerization

All these single mechanism polymerization lacks in ability to design block copolymers from several monomers that are polymerizable by different polymerization mechanisms. However , transformation polymerization can utilize various mechanisms for the synthesis of block copolymers via a chain-transformation. Transformation polymerization provides a useful alternative for the synthesis of block, graft and star copolymers consisting of two monomers that are polymerized only by two different mechanisms. In this paper, poly(isobutylene-b-styrene) and poly(isobutylene-b-butyl acrylate) copolymers were synthesized through transformation of living cationic polymerization into radical polymerization.Poly(isobutylene-b-styrene) diblock copolymer was prepared by a three-step process. Isobutylene was polymerized by cumyl chloride initiator in conjuntion with TiCl₄ coinitiator in CH₂Cl₂/n-hexane solvent mixtures at -80 ℃. Poly isobutylene carring a-isobutenyl was obtained by...