Industrial Chemistry and Materials Engineering Department, Engineering Faculty, University of Messina, Contrada di Dio, Vill. S. Agata, I-98166 Messina, Italy
Chemical Science Department, University of Catania, Catania, Italy
Biostructures and Bioimages Institute-CNR-Support Organizational Unit of Catania, Catania, Italy
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STUDY OF THE RADICAL SPECIES INDUCED BY ELECTRON-BEAM IRRADIATION IN VACUUM ON BIOMEDICAL UHMWPE
Ultra high molecular weight polyethylene (UHMWPE) is a component of mobile prostheses. The irradiation performed to sterilize and cross-link the polymer limits its life because of the free radicals originated during this process. In this work, a UHMWPE was electron-beam irradiated under high vacuum and annealed. Mechanical tests were performed on the UHMWPE samples before and after the annealing treatment. The results were compared with a study of radical species type and amount and the crystalline degree changes. Experimental results show that the annealing treatment prevents degrading reactions, favors intermolecular and/or intramolecular chemical rearrangements, and improves wear resistance without compromising the typical elasto-plastic mechanical behavior.
STUDY OF THE RADICAL SPECIES INDUCED BY ELECTRON-BEAM IRRADIATION IN VACUUM ON BIOMEDICAL UHMWPE