Kinetics of radiation polymerization of vinyl benzoate

Abstract

Abstract Vinyl benzoate was polymerized by γ-radiation from a cobalt-60 source and the kinetics of polymerization were studied at several temperatures. The results showed that the rate of polymerization was proportional to I0.66 , where I is the radiation dose rate. The net activation energy for the polymerization reaction, (Ep -1/2 Et ), was found to be 3.62 kcal, where Ep and Et are the activation energies for the propagation and termination stages of the reaction. The radical yield measured by the loss of DPPH in the solution after irradiation was G=5.0, while the G (Radical) effective in initiating polymerization was 0.94. The ratio of the rate constants, k2 p/kt = 5.8 × 10−4 at 60° and 1.59 × 10−4 at 25° The rate of polymerization was higher than that of styrene but lower than that of vinyl acetate under comparable conditions.