The effect of crystallization conditions on radiation-induced crosslink formation in polyethylene

Abstract

It had previously been found that the decrease in solubility of single crystal polyethylene with high energy radiation dose was different from that in the bulk material. The radiation dose needed to obtain gelation also depended on preparation conditions. As part of a series of experiments investigating these effects electron spin resonance spectroscopy has been used to study free radical formation in irradiated single crystal and bulk polyethylene. It has been found that the radical yields were the same in all the polyethylene preparations studied. It was also found that the rate of alkyl radical decay at room temperature depended on the crystallization conditions and the pre-irradiation annealing. The longer the crystal long spacing, the more stable were the radicals.