Evaluation of the Tensile Strength of Electron Beam Irradiated Powdered Ultra High Molecular Weight-Polyethylene (UHMWPE) Prior to Sintering
Résumé
We have studied the variation in tensile strength (sigma(b)), fracture strain (epsilon(f)) and Young modulus (d sigma/d epsilon) of low voltage electron beam irradiation (HLEBI) on powdered ultra-high molecular weight-polyethylene from 0.043 to 0.43 MGy prior to sintering. The low dose of 0.043 MGy-HLEBI enhanced the ob, epsilon(f) and d sigma/d epsilon, as well as increased the crystallinity ratio from 37 to 46% evaluated by differential scanning calorimetry (DSC). An additional dose apparently decreased the ab and ef, as well as the melting point from approximately 412 to 406 K and the crystallinity ratio from 46 to 43% for 0.043 to 0.43 MGy, respectively. Irradiation induces two competitive mechanisms, namely (i) the scission of chains and (ii) the crosslinking of chains. The discussion is focused on these mechanisms.