POLYMERIZATION OF STYRENE AND METHYL METHACRYLATE DURING THE FORMATION OF PARTICLES OF POLYMER SUSPENSIONS STABILIZED BY OLIGODIMETHYLSILOXANES IN VARIOUS TEMPERATURE CONDITIONS

The article presents data on the study of the polymerization temperature effect on the properties of polymer suspensions (particle diameter, particle size distribution and aggregate stability) obtained in the presence of water-insoluble organosilicon surfactants. The effect of temperature was studied during heterophase polymerization of styrene and methyl methacrylate in the presence of organosilicon surfactants of various structures with terminal amino and glycidoxy groups (alpha, omega-bis (trimethylsiloxy-oligodimethylmethyl (3-aminopropyl) siloxane (PMADMS(1)) and alpha, omega-bis [3-glycidoxypropyll poly-dimethylsiloxane (PDMS (CHOCH2)). Polymerization was carried out in different temperature conditions. The dependence of the polymerization rate and particle diameter on the synthesis temperature was revealed. With increasing temperature, the rate increases, and the particle diameter decreases (from 1.1 mu m to 0.4 mu m). It was shown that the activation energy of styrene polymerization in the presence of organosilicon surfactants of various structures is 25.4 and 33.4 J/mol, which is close to the values usually observed during radical heterophase polymerization. A decrease in the polymerization temperature leads to an increase in the induction period on the conversion/time kinetic curves. A detailed study of the initial stage of polymerization of methyl methacrylate at different temperatures showed that the particle diameter is determined at the initial stage of polymerization and depends significantly on the temperature of the process. In the case of the synthesis of polymer suspensions at a constant temperature throughout the entire polymerization process, the temperature value does not significantly affect the aggregate stability of the obtained polymer particles. In this case, the aggregate stability of polymer suspensions is influenced by the rate of an interfacial adsorption layer formation from molecules of an organosilicon surfactant and polymer, which is formed at the initial stage of the polymerization process.