Akademik Veri Yönetim Sistemi
International Journal of Radiation Applications and Instrumentation. Part, cilt.36, sa.3, ss.345-351, 1990 (Scopus)
The drawing behaviour of crosslinked high density polyethylene was investigated. The crosslinking was carried out under ultraviolet (UV) radiation in the presence of acetophenone. The mechanical properties of crosslinked and drawn samples were evaluated as a function of UV-irradiation time and gel content. These samples were also exposed to γ-radiation in air. It was found that the maximum attainable draw ratio decayed exponentially with UV-irradiation time. Although the mechanical properties of the drawn and undrawn crosslinked materials increased at low levels of crosslinked densities, they subsequently decayed and assumed asymptotic values. These results were interpreted in terms of initial increase in the molecular weight and subsequent chain scission and reduction in the molecular mobility due to crosslinking. In crosslinked and drawn samples, the rate of γ-radiation induced oxidative degradation appears to increase with UV-irradiation time as a result of residual stress which reduces the activation energy for chain scission, and microvoiding which increase the solubility and diffusivity of oxygen in the drawn material. © 1990.