Analysis of mechanism of the catalytic effect of hydrogen on the decay of alkyl macroradicals in polyethylene

The suggested one-step and two-step mechanism of decay of alkyl macroradicals in polyethylene are analyzed in detail at the activation energy level. For the one-step mechanism, the BEBO method is modified for reactions proceeding via a three-particle state. For the two-step mechanism, a three-process kinetic model is used; the contributions to the total energy barrier are calculated by the original BEBO method for two-particle transition states and by a molecular model for the diffusion of simple penetrants in polymers. The results indicate that the catalytic effect of hydrogen on the migration of the alkyls in the amorphous phase proceeds by the two-step mechanism.