Preparation of Comb-Like Copolymers with Amphiphilic Poly(ethylene oxide)-b-polystyrene Graft Chains by Combination of Graft From and Graft Onto Strategies

A novel method for preparation the comb-like copolymers with amphihilic poly(ethylene oxide)-block-poly(styrene) (PEO-b-PS) graft chains by graft from and graft onto strategies were reported. The ring-opening copolymerization of ethylene oxide (EO) and ethoxyethyl glycidyl ether (EEGE) was carried out first using alpha-methoxyl-omega-hydroxyl-poly(ethylene oxide) (mPEO) and diphenylmethyl potassium (DPMK) as coinitiation system, then the EEGE units on resulting linear copolymer mPEO-b-Poly(EO-co-EEGE) were hydrolyzed and the recovered hydroxyl groups were reacted with 2-bromoisobutyryl bromide. The obtained macroinitiator mPEO-b-Poly(EO-co-BiBGE) can initiate the polymerization of styrene by ATRP via the Graft from strategy, and the comb-like copolymers mPEO-b-[Poly(EO-co-Gly)-g-PS] were obtained. Afterwards, the TEMPO-PEO was prepared by ring-opening polymerization (ROP) of EO initiated by 4-hydroxyl-2,2,6,6-tetramethyl piperdinyl-oxy (HTEMPO) and DPMK, and then coupled with mPEO-b-[Poly(EO-co-Gly)-g-PS] by atom transfer nitroxide radical coupling reaction in the presence of cuprous bromide (CuBr)/N,N,N',N '',N ''-pentamethyldiethylenetriamine (PMDETA) via Graft onto method. The comb-like block copolymers mPEO-b-[Poly(EO-co-Gly)-g-(PS-b-PEO)] were obtained with high efficiency (>= 90%). The final product and intermediates were characterized in detail. (C) 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1930-1938, 2009