To evaluate the amount of each kind of radicals that have been generated on different starting Radical species have been assigned on the basis of their EPR spectra. A rationalization between theseĭifferent parameters have been performed in order to evaluate the stability of polymer samples The structure of the polymer (number of double bonds, or crystallinity) is strictlyĬonnected to the response of the sample itself to the irradiation. *Corresponding author: Paganini Maria Cristina, Dipartimento di Chimica Università di Torino, via Keywords: EPR, Defects, Double bonds, Crystallinity, Irradiation Towards high energy irradiation processes. Prosthetic components is commonly carried out by high energy radiation.1 Ultra High Molecular Weight Polyethylene (UHMWPE) is one of the most interesting materialįor the articulating surface in total joint replacements. The initial effect produced in solid polymers by the action of high energy radiations is theįormation of macro-radicals. Conventional CW-EPR techniques have been widely applied Electron Paramagnetic Resonance (EPR) spectroscopy, due to itsĬapability of detecting radical species, is one of the most direct and informative techniques to elicit Ī large body of work exists concerning the formation and characterization of radicals in The primary products are involved, after their formation, inĬomplex secondary reactions which result in radiation chemical effects such as crosslinking, gasĮvolution, unsaturation in chemical bonding. Radicals have been detected by electron spin resonance studies.ĮPR technique is used not only for the identification of different radicals or defects but also for Possible radicals that might be produced by irradiation process, the secondary alkyl and the allyl In the past to study radical intermediates generated by irradiation of polyethylene. Of the sample with EPR results, it is possible to correlate the amount of defect generated during the Spectroscopic techniques related to the number of double bonds or to the percentage of crystallinity Quantitative evaluations of radicals themselves. In this work we used and elaborated EPR results to obtain some new information about the trend Irradiation with the structure of the starting material. Of different radicals vs the amount of irradiation dose. We aimed to stabilizeĪ correlation between structural properties of the materials used and their sensitivity towards Polyethylene samples that differ in crystallinity and number of double bonds. Two different medical gradeUHMWPES were used as resin powders with a molecular mass higher Irradiation to identify the more stable material even after high dose irradiation.

Bruker epr iris motor