RADICAL POLYMERIZATION AND COPOLYMERIZATION BEHAVIOR OF METHYL ALPHA-(PHENOXYMETHYL)ACRYLATE

Polymerization and copolymerization behavior of methyl alpha-(phenoxymethyl)-acrylate (MPMA) as a polymerizable acrylate bearing a large alpha-substituent was studied. The polymerization rate and molecular weight of the polymer were suppressed by a relatively high equilibrium monomer concentration: 0.19 mol l-1 at 60-degrees-C. The H-1 NMR spectra of the homopolymer and copolymer with methyl methacrylate showed peaks due to the unsaturated end group introduced by the addition-fragmentation reaction. No fragmentation occurred in the copolymerization with styrene, and Q = 1.20 and e = 0.87 were evaluated for MPMA. Although 2-substitution of MPMA might accelerate fragmentation, a small amount of 2-methoxy- or 2-ethoxy-MPMA decreased simultaneously the polymerization rate of methyl methacrylate and molecular weight of the resultant polymer. These effects of the substituted MPMA on the polymerization of methyl methacrylate were ascribable to quite low reactivities of poly(2-substituted MPMA) radicals.