Accelerated and Natural Aging of UHMWPE

Representative load-displacement curve obtained from bearing surfaces of three acetabular components irradiated and stored in either nitrogen or air. After 10 years storage in nitrogen, load-displacement curve is nearly identical to that obtained immediately poststerilization in nitrogen. Component irradiated and stored in air is substantially degraded after only 5 years. Base resin was GUR 1020 compression molded in all cases. (Adapted from Edidin et al. 2000.) 

Clearly oxidative chain scission has an effect on mechanical performance similar to reduction of molecular weight ah initio. This experiment provided the strongest mechanical evidence of oxidation to date, in that a mechanistic relationship between oxidation and molecular weight was displayed. 

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