SYNTHESIS AND PROPERTIES OF POLYMER SUSPENSIONS OBTAINED BY HETEROPHASE POLYMERIZATION IN THE PRESENCE OF α,ω BIS[3 GLYCIDOXYPROPYL]POLYDIMETHYLSILOXANE

Abstract

Polymeric microspheres with glycidoxy groups on the surface can be used as bioligand carriers in diagnostic test systems. However, the possibility of synthesizing aggregatively stable functional polymeric microspheres in a wide range of diameters is an urgent problem of modern polymer chemistry. This article is devoted to a systematic study of the kinetics of styrene and methyl methacrylate polymerization in the presence of an organosiloxane surfactant with terminal glycidoxy groups – α,ω-bis[3-glycidoxyproopyl]-polydimethylsiloxane, PDMS(CHOCH2). The article shows the influence of phases volume ratio, initiator and surfactant concentration, synthesis temperature and pH of initial medium on the properties of polymer suspensions (their aggregative stability, monodispersity, particle diameter). The formation of polymer-monomer particles during polymerization has been studied and it has been shown that polymer suspensions retain high aggregation stability from early period of monomer conversion, and the particle diameter changes untill 30% of the monomer conversion. Due to the high surface activity of the organosiloxane surfactant used and its incompatibility with the resulting polymer, aggregatively stable functional polymer suspensions with diameters from 0.09 to 1.1 μm were obtained by a single-stage synthesis. Studies of the hydration degree of polymer microspheres have shown that the presence of functional glycidoxy groups on their surface ensures the formation of a hydration shell, which increases the stability of polymer particles, and also makes it possible to use the resulting microspheres as carriers of bioligands. Thus, the use of water-insoluble organosiloxane surfactants as stabilizers for the heterophase polymerization of vinyl monomers makes it possible to synthesize aggregatively stable functional polymer suspensions in a wide range of diameters. The use of organosiloxane surfactants with various functional groups expands the range of functional polymer microspheres used in various fields of application.