Syndiotactic-specific polymerization of methacrylates by tertiary phosphine-triethylaluminum

Abstract

Polymerization of MMA with R3P-R3′Al in toluene at low temperatures was reinvestigated and was found to give highly syndiotactic PMMA. Among the initiators examined Ph3P-Et3Al gave the PMMA with highest syndiotacticity and the polymerization at −93°C yielded PMMA with rr content of 95%. PMMAs prepared with Et3P-Et3Al and Ph3P-Et3Al contained the structural unit comprised of the phosphine components at the chain end as evidenced by 31P and 1H NMR analyses. The results clearly indicate that R3P takes an important role in the initiation process, though R3P alone does not polymerize MMA. Methacrylic acid esters of primary and secondary alcohols were also polymerized by these initiators to give highly syndiotactic polymers. Block and random copolymers of MMA with several methacrylates were also obtained. The effect of syndiotacticity on the glass transition temperature (Tg) of PMMA was examined and Tg for 100% syndiotactic PMMA with infinite molecular weight was estimated to be 141°C. © 1992, The Society of Polymer Science, Japan. All rights reserved.