Thermal stability and creep properties of radiation crosslinked ultra-high molecular weight polyethylene

The effects of γ-ray irradiation on the thermal stability and creep resistance of ultra-high molecular weight polyethylene (UHMWPE) were studied. First, UHMWPE powder was hot pressed into 1 mm thick sheets using a vulcanization molding machine. The chemical structure, thermal stability, microstructure, tensile properties, and creep properties of the irradiated plate samples were studied. The results demonstrated that, after γ-ray irradiation, the melting points, crystallinity, and thermal stability increased; the gel content increased to 89%; and the motility of molecular chains decreased. Compared with the creep resistance of the unirradiated sample, that of the irradiated sample increased by approximately 40%. In this study, the thermal stability and creep resistance of UHMWPE were significantly improved via the radiation cross-linking process, which provided a method for the preparation of UHMWPE materials with high creep resistance and high thermal stability.