Studies on the tacticity of poly(methyl methacrylate) synthesized by atom transfer radical polymerization

Two series of PMMA samples have been synthesized by Atom Transfer Radical P olymerization (ATRP) with and without catalytic promoter(aluminum isopropox ide, (i-PrO)(3)Al in the temperature range of 0 similar to 100 degreesC. Th eir tacticity has teen determined by C-13 Nuclear Magnetic Resonance(NMR). The results showed that the polymers by ATRP were all predominantly syndiot actic, and the tendency to form syndiotactic sequences decreased with the p olymerization temperature increase, The tacticity of PMMA was influenced by catalytic promoter, [(i-PrO)(3)Al], because it coordinates with the ester carbonyl group of polymer chain end, The activation parameters governing th e tacticity of ATRP were calculated, The results indicate that the same typ e of active species is present in ATRP and conventional radical system.