Surface crosslinking of polyethylene by electron beam irradiation in air

• Published in: Polymer (Guilford) Vol. 39; no. 24; pp. 6115 - 6120
• Main Authors: Tretinnikov, Oleg N., Ogata, Sakae, Ikada, Yoshito
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.11.1998; Elsevier
• Subjects: Applied sciences; crosslinking; Crosslinking and degradation; electron beam irradiation; Exact sciences and technology; Physicochemistry of polymers; Polymers and radiations; ultra-high molecular weight polyethylene; electron beam irradiation; crosslinking; ultra-high molecular weight polyethylene; Surface hardness; Polyethylene; Surface reaction; Solid state reaction; Mechanical properties; Electron beam; Reaction mechanism; Experimental study; Microhardness; Radiochemical crosslinking
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/S0032-3861(98)00075-5

Ultra-high molecular weight polyethylene (UHMWPE) was irradiated by electron beams to a dose of 100 kGy at a dose rate of 20 kGy min −1 and the near-surface region of the irradiated polymer was characterized by means of attenuated total reflection Fourier-transform infra-red (ATR FTi.r.) spectroscopy and micro-hardness measurement. The results obtained strongly suggest that irradiation in air introduced hydroperoxide groups into the polymer without formation of any other oxygen-containing groups. The generated hydroperoxides could be decomposed further by subsequent heat treatment of the irradiated polymer, resulting in crosslinking of UHMWPE chains in the near-surface region of the material. As a result of this surface modification, the surface hardness of UHMWPE substantially increased.