RADIATION EFFECTS INDUCED BY MeV ELECTRON BEAMS IRRADIATING DENSE POLYETHYLENE (UHMWPE)

Ultra-high-molecular-weight-polyethylene (UHMWPE) is irradiated with 5 MeV electrons in vacuum at different doses. The radiation effects induced by the electron irradiation are investigated by using different physical analyses such as mechanical tensile stress measurement, hardness measurements, specific heat measurements, infrared molecular absorption, surface wetting, polymer darkness and morphological scanning electron microscopy. The results indicate that the effects induced by high electron dose absorption consist mainly of a dehydrogenation of the polymer with an increase of the C-C cross-linking bonds, of an increase of the macroscopic mechanical resistance of the polymer, and of a darkness increase of the polymer color. Obtained results are compared with those produced by ion irradiation of the polymer by using ion implants at different stopping powers. Some applications of electron-irradiated UHMWPE are presented and discussed.