Abstract

Ultra-high molecular weight polyethylene (UHMWPE) is the preferred interposition biomaterial for orthopedic prostheses. Its microstructure, based on the extremely high molecular weight, leads to optimal mechanical properties. High energy irradiation may cause chain scission and/or crosslinking of polymers. Samples of UHMWPE were γ-irradiated and afterward, the soluble part (short-chain molecules) was extracted by the Soxhlet method using xylene as a solvent. The insoluble part (crosslinked part) was etched by permanganic solution to reveal its morphology. SEM images of the insoluble part samples show variations in the surface texture as well as degradation, which are probably caused by the irradiation effects (chain scission and oxidative degradation) as well as the action of the solvent and etching. Finally, some samples show a well-defined spherulitic structure.