The Effect of a Solvent on the Rate of Hydrogen Atom Abstraction from Cumene by the Propagating Radical of Poly(vinyl acetate)

Abstract

Polymerization of vinyl acetate in benzene (0, 20, 30 and 50 vol%) was carried out at 30°C by using α, α′-azobisisobutyronitrile (AIBN) asan initiator and cumene as a chain transfer agent. The Tate of polymerization (Rp) decreased markedly with the increase in both benzene and cumene concentrations. The chain transfer-constant to cumene (Cs) changed a little with the change in benzene concentration. The rate constant of propagation (Kp) decreased with the increase in benzene concentration. The rate constant of hydrogen atom abstraction from cumene by the propagating radical of poly (vinyl acetate) (Kabs) was derived on the basis of the values of Cs andKp. The values of Kabs decreased with the increase in benzene concentration and were approkimately proportional to the values of Kp.