Synthesis by ATRP of triblock copolymers with densely grafted styrenic endblocks from a polyisobutylene macroinitiator

A macroinitiator was prepared from a triblock copolymer of polyisobutylene (PIB) with end blocks of poly(p-methylstyrene) (P(p-MeS)) by bromination to obtain initiating bromomethyl groups for atom transfer radical polymerizat ion (ATRP). Controlled polymerization of styrene and p-acetoxystyrene yield s new triblock copolymer structures with densely grafted end blocks. Simult aneously, however, thermally initiated polymerizations can be observed by s ize exclusion chromatography (SEC) which were also controlled yielding low molecular weight polymers with narrow distributions. A tendency to crosslin king can be suppressed by selection of the polymerization conditions.