Influence of the a-tocopherol load and the annealing treatment on the wear resistance of biomedical UHMWPE radiated with electron beam

The biomedical UHMWPE, electron beam radiated in air with doses raging between 25-100 KGy, was doped with different amount of -tocopherol (0,1-0,7 wt%) to avoid its oxidative degradation. The polymer was annealed just after the radiation at 110°C/24 hours. Physical and mechanical tests were performed on the UHMWPE before and after the radiation and on neat or doped material. Results showed that the heating treatment after the radiation improves cross links in the UHMWPE and a-tocopherol has a good antioxidant action. The UHMWPE blended with 0.7 % of antioxidant became harder and more wear resistant (+52%) after the irradiation with 100 KGy.