Modificação química de polietileno de alto peso molecular através de radiação gama para aplicação em biomateriais

Abstract

The high molecular weight polyethylene (PEAPM) is a polymer having desirable characteristics such as: good mechanical properties, low coefficient of friction and selflubricating surface. This combination of properties confers use as orthopedic prostheses, however, when compared to metals their properties are still inferior making it necessary to increase mainly its tensile strength. The most processes can be used for this purpose, this study will be evaluated using gamma radiation to increase the tensile strength of polyethylene. Also reported is the effect of addition of ascorbic acid (vitamin C) and tocopherol (vitamin E) in mechanical and tribological properties of the polyethylene. To achieve this goal we used a planning of factorial experiments 2 ^ 3, with the following input variables: concentration of vitamin E, vitamin C concentration and radiation dose. response variables analyzed were obtained by the following techniques: Gel content testing, dynamic mechanical analysis (DMA - crosslink density), analysis of infrared spectroscopy (FTIR - oxidation index and crosslinking index), tensile test ( modulus, maximum stress, yield stress) analysis tribological (friction coefficient, maximum depth). Schedules demonstrated that PEAPM with addition of 3% vitamin E and radiation dose of 100 kGy showed better tribological, chemical and mechanical properties for use as a biomaterial polymer.