Propagation and termination processes in free radical copolymerization

Abstract

Abstract The propagation and termination processes in free radical copolymerization were discussed on the basis of current experimental data. It was shown that the penultimate unit effect (PUE) in propagation is very general, affecting not only the absolute values of the rate constant but also the monomer reactivity ratios r 1 and r 2 . The analysis suggests that the alternating index r 1 r 2 originates in the PUE. An adequate description of the termination process also requires a penultimate model, which leads to a general, yet simple two‐parameter rate‐of‐copolymerization equation with PUEs in both propagation and termination.