The effects of hydrogen peroxide and sterilization on the structure of ultra high molecular weight polyethylene

• Published in: Polymer degradation and stability 1998-01, Vol.62 (1), p.97-104
• Main Authors: Goldman, M., Gronsky, R., Long, G.G., Pruitt, L.
• Format: Article
• Language: English
• Subjects: Ageing; Applied sciences; Exact sciences and technology; Physical properties; Polymer industry, paints, wood; Properties and testing; Technology of polymers
• ISSN: 0141-3910; 1873-2321
• DOI: 10.1016/S0141-3910(97)00265-6

The effects of hydrogen peroxide and sterilization on the structure and morphology of medical-grade ultra high molecular weight polyethylene (UHMWPE) were studied. Microstructural changes were induced via gamma irradiation sterilization and were accelerated by aging in hydrogen peroxide. Differential scanning calorimetry, density gradient column, transmission electron microscopy and small-angle X-ray scattering were used to characterize the structure. Upon oxidation, a decrease in melting temperature, an increase in heat of fusion, an increase in density, a tortuosity in lamellae, and a tendency to microcrack were observed. Based on the results, a mechanism for the oxidation of UHMWPE is proposed in which oxygen is incorporated into the amorphous phase of the polymer, leading to the development of strains and the breaking of tie molecules in the polymer, which result in the microcracking and embrittlement of the material.