ORGANOCUPRATES INITIATED ANIONIC LIVING POLYMERIZATION OF TERT-BUTYL METHACRYLATE

We report organocuprates initiated anionic polymerizations of various alpha,beta-unsaturated eater monomers in tetrahydrofuran (THF) under v arious conditions. It was found that catalysts prepared by reaction of CuI with methyllithium (MeLi) very effectively cause the polymerizati on of meth(acrylate) monomers. At molar ratio of [MeLi] to [CuI] highe r than 2 the polymerization of t-butyl methacrylate (TBMA) proceeded q uantitatively in THF at 0-45 degrees C to afford high molecular weight poly(t-butyl methacrylate) (PTBMA) with extremely narrow molecular we ight distribution (MWD) (M-w/M-n=1.0(5)-1.1(7)). Initiator efficiency was less than 10% and highest at about [MeLi]/[Cul]=4.0. The post-poly merization proved the livingness of the polymerization of TBMA caused by lithium methylcuprate in THF at 0 degrees C. The active species for the polymerization of TBMA was thought to be higher cuprate, such as Li2Cu(CH3)(3). For the polymerizations of other methacrylates and I-bu tyl acrylate lithium methylcuprate initiators effectively afforded the polymers but with very bread MWD.