STERILIZATION AND LONG-TERM AGING OF MEDICAL-GRADE UHMWPE

摘要

Changes in the molecular structure of UHMWPE take place during the sterilization of implant components using ionizing irradiation. Irradiation in air reduces the molecular weight, which is important for the tribological behaviour by oxidation and produces accelerated aging of the polymer. The amount of this oxidation is dependent on the irradiation time and the absorbed dose. The use of a nitrogen atmosphere during irradiation and the subsequent storage results in less oxidation and therefore predominant cross-linking of the polyethylene occurs. The positive, ductile material properties of this polymer are maintained.