Graft Copolymers by Combined Anionic and Cationic Polymerizations Based on the Homopolymerization of a Bifunctional Monomer

Abstract

The bifunctional monomer 2-(vinyloxy)ethyl methacrylate (VEMA) was polymerized both anionically and cationically. Using 1,1-diphenylhexyllithium (DPHL) as initiator, tetrahydrofuran (THF) as solvent and the low temperature of −60 °C, the CC double bond of the methacryloyl group of VEMA underwent smoothly anionic polymerization, without cross-linking or side reactions. The polymer had a controlled molecular weight and a narrow molecular weight distribution (Mw/Mn = 1.06−1.12). On the other hand, the CC double bond of the vinyloxy group of VEMA can undergo cationic polymerization. A polymer with controlled molecular weight and narrow molecular weight distribution (Mw/Mn = 1.11−1.13) was prepared using 2-[1-acetoxyethoxy]ethyl methacrylate (4)/EtAlCl2 as initiator in the presence of THF, a weak Lewis base. Two methods were employed to prepare graft copolymers. (A) The anionically prepared polymer of VEMA was separated from solution after quenching the polymerization and purified by freeze-drying; then the vi...