Emulsion copolymerization of methyl methacrylate with ethyl acrylate, 1. Effect of the initiator concentration on the polymerization behaviour

Abstract

AbstractThe emulsion copolymerization of methyl methacrylate with ethyl acrylate, initiated by ammonium persulfate in the presence of both anionic and nonionic emulsifiers, was kinetically investigated at 60°C by the conventional gravimetric method. In the range of low conversions the rate of polymerization was found to be proportional to the 0,5 power of the initiator concentration. Over the range of medium conversions the rate of polymerization is approximately proportional to the 0,35 power of the initiator concentration and the number‐average molecular weight is inversely proportional to the 0,4 power of the initiator concentration. The molecular weight increases up to 30% conversion and then it remains constant up to the total monomer consumption. It was found that the mean particle diameter decreases while the number of particles per volume unit, the conductivity of final latices, the coagulate yield and the number of radicals per particle increase with increasing concentration of the initiator.