Electron beam irradiation-induced oxidation of molten ultra-high molecular weight polyethylene films

This study employed electron beam irradiation technology to perform radiation-induced oxidative treatment on ultra-high molecular weight polyethylene (UHMWPE) films under air and oxygen atmospheres, in molten (150 ℃) and room temperature (25 ℃) states. The structural and mechanical properties were analyzed through Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), gel content measurement, and small punch tests. The experimental results indicate that irradiation at room temperature primarily induces cross-linking in UHMWPE, with a low degree of oxidation. In contrast, irradiation in the molten state under an oxygen atmosphere triggered significant oxidative degradation. At an absorbed dose of 500 kGy, the gel content was reduced to zero, accompanied by a notable decline in mechanical properties, and the small punch tests exhibited characteristics of brittle fracture. Irradiation in the molten state under an air atmosphere also demonstrated a synergistic effect between cross-linking and oxidation. The study confirms that electron beam irradiation of molten UHMWPE films in an oxygen atmosphere can efficiently promote oxidative degradation, offering a new strategy for the chemical recycling of polyethylene.