Abstract: | The graft polymerization of styrene onto preirradiated poly(isobutylene oxide) (PIBO) with methanol and benzene was studied. The order of grafting yield and of the number-average molecular weight of graft chains decrease in the order; undiluted styrene > styrene–methanol (1:1) solution > styrene–benzene (1:1) solution. A kinetic treatment to calculate rate constants from the rate of grafting and the molecular weight of the graft chain was proposed. The propagation rate constant kp was 0.2–0.3 l./mole-sec and the termination rate constant kt was 1.0–16.0 l./mole-sec. The ratio kp/kt in this heterogeneous system was larger than that in homogeneous system by a factor of about 104–105. |