Polymerization of Vinyl Monomers with Metal Salts

II. Polymerization of Methyl Methacrylate with Group II_b Metal Nitrates

Abstract

Polymerization of methyl methacrylate, acrylonitrile and styrene with various metal nitrates were investigated at 100°C in acetone solution. Among the metal nitrates, especially group IIb metal (Zn, Cd, Hg) nitrates showed high catalytic activities for the polymerization of methyl methacrylate. Neither halides nor perchlorate of group IIb metal polymerized methyl methacrylate. It was found from kinetic experiments that the rate was proportional to the square root of the salt concentration. By addition of 1, 1-diphenyl-2-picrylhydrazil (DPPH) the polymerization was inhibited. Monomer-copolymer composition curves from copolymerization of methyl methacrylate with acrylonitrile and with styrene were similar to those of usual radical copolymerizations. From these facts as well as that NO₃ group was found in the poly (methyl methacrylate) obtained with the metal nitrates, a radical propagation mechanism initiated by the reaction between the monomer and the nitrates was proposed.