Novel brush copolymers via controlled radical polymerization

A combination of reversible addn.-fragmentation chain transfer (RAFT) polymn. and atom transfer radical polymn. (ATRP) techniques were applied for the synthesis of novel polymer brushes by using the \"grafting from\" approach or a combination of \"grafting through\" and \"grafting from\" methods. The procedure included the following steps: (1) Synthesis of 2-(2-bromoisobutyryloxy)ethyl methacrylate (BIEM), (2a) RAFT homopolymn. of BIEM to obtain PBIEM as the polymer backbone. (2B) RAFT copolymn. of BIEM and PEO macromonomer (PEOMA, .hivin.Mw = 450 g . mol-1, .hivin.D.hivin.PPEO = 9) to obtain a more hydrophilic polymer backbone. Well-controlled copolymers contg. almost 25 mol-% of PEOMA were obtained, and (3) ATRP homopolymn. of Me acrylate (MA) and copolymn. of MA with 1-octene using both PBIEM homopolymer and poly(BIEM-co-PEOMA) as polyinitiators resulted in brushes with densely grafted homopolymer and copolymer side chains, resp. Well-controlled copolymer side chains contg. 15 mol-% of 1-octene were obtained. Relatively narrow molar mass distributions (MMD) were obtained for the ATRP expts. The formation of the side chains was monitored using size exclusion chromatog. (SEC) and NMR spectroscopy. The copolymer compn. in the side chain was confirmed using 1H NMR spectroscopy. Contact angle measurements indicated that for the brush polymers, contg. 1-octene in the side chain, there was a decrease in the surface energy, as compared with the brush polymers contg. only the homopolymer of MA in the side chain