HIGHLY SYNDIOTACTIC POLY(METHYL METHACRYLATE) WITH NARROW MOLECULAR-WEIGHT DISTRIBUTION FORMED BY TERT-BUTYLLITHIUM-TRIALKYLALUMINIUM IN TOLUENE

Polymerization of MMA with t-C4H9Li in toluene in the presence of trialkyaluminum (alkyl=methyl, ethyl, butyl, isobutyl, and octyl) was examined at various Al/Li ratios. Triethyl-, tributyl- and trioctylaluminums worked quite effectively in the polymerization to give highly syndiotactic PMMA with narrow molecular weight distribution (MWD) at the Al/Li ratio of 3 and higher than 3. The highest syndiotacticity of 96% was attained at -93°C. The polymerization was initiated by t-C4H9- anion and proceeded in a living manner. The structure of the syndiotactic PMMA is chemically identical to that of isotactic PMMA prepared with t-C4H9MgBr. Consequently, highly isotactic and syndiotactic PMMAs with narrow MWD and with the same chemical structure from α-end to ω-end were obtained.