Recent efforts to obtain block copolymers by combination of living carbocationic and anionic polymerizations are presented.When tolyl-ended polyisobutylene was used as macroinitiator of anionic polymerization of methacrylate derivatives mixtures of homopolymers and block copolymers were formed due to incomplete lithiation of this chain end.In another approach a new functionalization method was developed by end-quenching living polyisobutylene with 1,1-diphenylethylene. After transformation of the groups into 2,2-diphenylvinyl end groups and lithiation polymers were synthesized from protected acrylate monomers. After partial deprotection a network could be formed by reaction with diisocyanate. Complete deprotection yielded a new amphiphilic network containing polyisobutylene and poly(2-hydroxyethyl) methacrylate segments crosslinked by urethane linkages.
|Publication status||Published - 1996|