Terpolymérisation acrylonitrile — styrène — acrylate de méthyle, 1. Etude cinétique de la terpolymérisation en émulsion, en réacteur fermé

Binary and ternary copolymerizations of the acrylonitrile (A) / styrene (S) / methyl acrylate (M) system were carried out by emulsion polymerization, using sodium lauryl sulfate as emulsifier and potassium persulfate as initiator. Kinetic studies of the reaction mixture by gas chromatography and simulation calculation of the copolymer composition versus conversion show that the classical theory of copolymerization (propagation rate by Markov chain 1st order) can be applied to the emulsion polymerization of this system, even at high conversion level. It was found that, when a conversion limit is obtained, the polymerization can be started again owing to a new addition of the more rapidly consumed monomer (styrene, in this case); it appears that both polymerization process and conversion effect do not involve appreciable variations of the polymer radical reactivity.