Thermal behavior and decomposition kinetic studies of biomedical UHMWPE/vitamin C compounds
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In this paper, the effects of adding vitamin C to biomedical ultra-high molecular weight polyethylene (B-UHMWPE) on thermal behavior and thermal degradation kinetics are investigated. The kinetic studies were conducted using Ozawa–Flynn–Wall (OFW), corresponding to pre-exponential factor (A) and activation energy (Ea). Compounds with 1.0 and 2.0% mass vitamin C exhibited a lower decomposition rate. Activation energy results from the OFW and Kissinger methods were close to each other and showed a dependence on the degree of conversion (α), with Ea being an increasing function of conversion degree to B-UHMWPE and a decreasing function for the compounds. Finally, the pre-exponential factor increases with the addition of vitamin C, favoring its interaction with the free radicals originated from the thermal degradation of B-UHMWPE, also suggesting a reduction in its decomposition rate.
KeywordsBiomedical UHMWPE Vitamin C Thermal stability Kinetic methods Activation energy
The authors are grateful to Brazilian Coordination for the Improvement in Higher-Level Personnel for scholarships. Moreover, characterizations provided by the Fast Solidification Laboratory of the Federal University of Paraiba and Northeast Center for Strategic Technologies (CETENE) are acknowledged as well.
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