Block copolymers by transformation of living anionic polymerization into controlled/'living' atom transfer radical polymerization

摘要

A method for the transformation of living anionic polymerization (LAP) to controlled/"living" atom transfer radical polymerization (ATRP) is reported and utilized for the preparation of block copolymers. The macroinitiators, polystyrene and polystyrene-block-polyisoprene containing the 2-bromoisobutyryl end group (PS-Br, M-bar_n=12 200, M-bar_w/M-bar_n=1.04; PS-b-PIP-Br, M-bar_n=16800, M-bar_w/M-bar_n=1.03), were prepared by LAP of styrene and styrene/isoprene, correspondingly, and suitable termination agents. These compounds were used as macroinitiators for controlled/"living" ATRP to prepare block copolymers with methyl acrylate (PS-b-PMA), butyl acrylate (PS-b-PBA), methyl methacrylate (PS-b-PMMA), a mixture of styrene and acrylonitrile (PS-b-P(S-r-AN)) and also chain extension with styrene (PS-b-PS and PS-b-PIP-b-PS). The block copolymers were characterized by means of size exclusion chromatography, ~1H NMR and FT-IR spectroscopy.