Kinetics of the γ‐radiation‐induced polymerization of methyl methacrylate in the solid state

Abstract Studies have been made of the γ‐radiation‐induced polymerization of methyl methacrylate in bulk, in the solid state at a temperature of −65°C. and a radiation intensity of 346,000 rad/hr. The reaction was found to have an extremely long induction period (∼50 hr.) when pure monomer was used, and to be first‐order with respect to polymer concentration. This first‐order dependency was confirmed by a series of irradiations in which 0.6% poly(methyl methacrylate) was dissolved in the monomer before irradiation. These irradiations showed no induction period. Nuclear magnetic resonance spectroscopy indicated a much more heterotactic polymer than that obtained in the liquid state at −49°C.