Diffusion‐controlled reaction. VI. Radiation graft polymerization of styrene to polyethylene

The radiation graft polymerization of styrene to polyethylene was studied under diffusion‐controlled conditions of radiation intensity I, monomer concentration M1, and polymer sample thickness L. The results of the present study together with previous work under diffusion‐free conditions verify our theoretical model for the diffusion‐controlled reaction. The grafting rate is inverse first order in L for diffusion‐controlled reaction and independent of L for diffusion‐free reaction. The order of dependence of grafting rate on radiation intensity for diffusion‐controlled reaction is one‐half that for diffusion‐free reaction. Diffusion control leads to a decrease in the order of dependence of grafting rate on monomer concentration. The decrease is greater than theoretically predicted; possible reasons for this effect are described.