Measurements of gas desorption from polyethylene-UHMWPE irradiated by 5 MeV electrons

Gas desorption in vacuum from electron irradiated ultra high molecular weight polyethylene (PE) is measured with a high sensible mass quadrupole spectrometer. Measurements are performed in thick PE irradiated with 5 MeV electron beams at doses of the order of tens of kGy. The irradiation modifies the PE molecules producing dehydrogenation, emission of different C-x-H-y groups, C-enrichment and carbon cross-linking processes. Results indicate that the radiation damage depends on the dose and that a significant change of chemical and physical polymer properties is reached for a critical dose of 18 kGy.