EPR investigation on radiation-induced graft copolymerization of styrene onto polyethylene: Energy transfer effects

The EPR measurements performed on polyethylene-co-styrene graft copolymers of various composition following low-temperature vacuum gamma irradiation have confirmed the decrease of the total radical yields with increasing the styrene concentration. The effect was partly attributed to the heterogeneity of the graft copolymer matrix and to the lack of molecular mobility in the solid state at low temperature, which prevents the attainment of the favourable geometrical configurations in intermolecular energy and charge transfer events.