Ultra high molecular weight polyethylene (UHMW-PE) is used extensively in hip and knee endoprostheses. Radiation damage from the sterilization of these endoprostheses prior to surgical insertion results in polymer crosslinking and decreased oxidative stability.; The motivation for this study was to determine if UHMW-PE could be crosslinked by low dose proton irradiation with minimal radiation damage and its subsequent deleterious effects. I found that low dose proton irradiation and post irradiation hydrogen annealing did crosslink UHMW-PE and limit post irradiation oxidation.; Crosslinking onset was investigated for UHMW-PE irradiated with 2.6 and 30 MeV H{dollar}sp+{dollar} ions at low doses from 5.7 {dollar}times{dollar} 10{dollar}sp{lcub}11{rcub}{dollar}-2.3 {dollar}times{dollar} 10{dollar}sp{lcub}14{rcub}{dollar} ions/cm{dollar}sp2{dollar}. Crosslinking was determined from gel permeation chromatography (GPC) of 1,2,4 trichlorobenzene sol fractions and increased with dose. Fourier transform infrared spectroscopy (FTIR) showed irradiation resulted in increased free radicals confirmed from increased carbonyl groups. Radiation damage, especially at the highest doses observed, also showed up in carbon double bonds and increased methyl end groups.; Hydrogen annealing after ion irradiation resulted in 40-50% decrease in FTIR absorption associated with carbonyl. The hydrogen annealing prevented further oxidation after aging for 1024 hours at 80{dollar}spcirc{dollar}C. Hydrogen annealing was successful in healing radiation damage through reacting with the free radicals generated during proton irradiation.; Polyethylenes, polyesters, and polyamides are used in diverse applications by the medical profession in the treatment of orthopedic impairments and cardiovascular disease and for neural implants. These artificial implants are sterilized with gamma irradiation prior to surgery and the resulting radiation damage can lead to accelerated deterioration of the implant properties. The findings in this study will greatly impact the continued use of these materials through the elimination of many problems associated with radiation damage from sterilization.; The higher energy transfer for proton compared to gamma irradiation greatly accelerated the radiation damage. Radiation damage increased linearly with dose over the range of doses examined. These results were consistent with findings from earlier researchers of gamma irradiation of polyethylene.
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