Influence of packaging conditions on the properties of gamma-irradiated UHMWPE following accelerated ageing and shelf ageing.

摘要: The ageing behaviour of ultra-high molecular weight polyethylene (UHMWPE) has been studied following gamma irradiation (25 or 40 kGy) in air inert atmosphere (vacuum packed). Accelerated procedures used elevated temperature (70°C) and/or pressurised oxygen (5 bar). Shelf for up to six months was also performed. variation polymer properties with depth into the determined using density measurements, infra-red spectroscopy and differential scanning calorimetry. Tensile irradiated after accelerated were determined. 20 days 4 resulted peaks density, crystallinity degree oxidation at surface. 8 these 500 μm below Where performed amount degradation (in oxidising conditions) generally lower but still significant. Differences observed tensile between material gamma-irradiated vacuum. This study indicated that performing sterilisation under conditions can reduce level UHMWPE when exposed an environment.