Synthesis of graft copolymers of the polystyrene-polysiloxane series

Abstract

The graft copolymerization of octamethylcyclotetrasiloxane with oligostyrenecarbocyclosiloxanes containing cyclosiloxane links attached as side groups to the main has been studied. Graft copolymers of the PS-polysiloxane series have been obtained, in which polydimethylsiloxane branches with various lengths are grafted to the carbon chain of the styrene oligomer. The composition of the copolymers obtained has been analysed by various methods. The kinetic dependence of the yield and viscosity of the systems that have been studied are S-shaped in nature, the slower initial period being longer in duration, the greater is the concentration of the oligostyrenecarbocyclosiloxane in the reagent mixture. The thermomechanical curves of the copolymers obtained point to the presence of transition temperatures corresponding to the glass temperatures of both the polydimethylsiloxane and also the PS blocks in the macromolecules of the graft copolymer.