Preparation of a copolymer of methyl methacrylate and 2-(dimethylamino)ethyl methacrylate with pendant 4-benzyloxy-2,2,6,6-tetramethyl-1-piperidinyloxy and its initiation of the graft polymerization of styrene by a controlled radical mechanism

The macroinitiator of a copolymer (PMDBTM) of methyl methacrylate (MMA) and 2-(dimethylamino)ethyl methacrylate (DAMA) with 4-benzyloxy-2,2,6,6-tetram ethyl- 1-piperidinyloxy (BTEMPO) pendant groups was prepared by the photoch emical reaction of tertiary amine groups of the copolymer with benzophenone in the presence of BTEMPO. The radical copolymerization of MMA and DAMA wa s carried out first with azo-bis-isobutyronitrile (AIBN) as an initiator; t hen, the dimethylamine groups of the copolymer constituted a charge-transfe r complex with benzophenone under UV irradiation, and the methylene of tern ary amine and diphenyl methanol radicals were produced. The former was capp ed by BTEMPO, and the nitroxide (BTEMPO) was attached to the polymeric back bone. The amount of pendant BTEMPO on PMDBTM was measured by H-1 NMR. PMDBT M initiated the graft polymerization of styrene via a controlled radical me chanism, and the molecular weight of the PMD-g-polystyrene increased with t he polymerization time. (C) 2001 John Wiley & Sons, Inc.