Electron beam irradiated UHMWPE: degrading action of air and hyaluronic acid.

Ultra high molecular weight polyethylene, both pure and electron beam irradiated, was exposed to air and hyaluronic acid. Physical and mechanical analyses were performed in order to check the polymeric change due to the treatment. Pure UHMWPE, in fact, was modified by the hyaluronic acid that plasticizes the polymer. The electron irradiation cross links the chains and prevents their sliding in acid presence. A low irradiation dose is preferable rather than an high one. Low doses induce low amount of free radicals, witch react with oxygen and hyaluronic acid inducing low polymer degrade maintaining the initial mechanical performance. High doses degrade significantly the polymer properties.100 kGy irradiation in air can be applicable on the polyethylene as well as a compromise between the low mechanical performance improving and the material degradation.