Thermal Graft Copolymerization of Styrene with Rubber I. Kinetics of Graft Copolymerization of Styrene with Polybutadiene

The changing of the overall rate of styrene polymerization and its constituents — homopolymerization rate and styrene grafting to the rubber in the interval of rubber concentration from 2 to 25% and in the temperature range 110–140°C was studied. Rubber works as a polymerization retarding agent when its concentration is at least 6% and with styrene conversion up to 15–20%. Specific degree of grafting polystyrene to rubber related to 1 weight part of rubber in isothermal copolymerization is shown not to depend on rubber concentration. Its limiting value at the investigated temperatures equals 200–220%. The specific degree of grafting can be increased at the stepped temperature-time regimes.