Modelling and kinetic study on radical polymerization of methyl methacrylate in bulk, 1. Propagation and termination rate coefficients and initiation efficiency

In this work the exact data of the rate coefficients of propagation kp and termination kt, and initiator efficiency f as well as their variations with conversion during the whole processes of the polymerization of methyl methacrylate in bulk have been measured using electron paramagnetic resonance (ESR) without any assumptions and approximations. kp was calculated directly from the synchronously measured data of the concentration of radicals and polymerization rate. kt was determined under nonsteady‐state conditions by using the after‐effect technique in the ESR measurement. f for the initiation with dimethyl 2,2′‐azoisobutyrate was evaluated from the initiation and termination rates. The ESR spectra show that the polymerization system is in a micro‐heterogeneous state and there exist inactive radicals. A model of a diffusion‐controlled reaction is proposed.