γ-線のポリエチレン表面層における照射効果

概要

論文の詳細を見る
In order to study the effects of irradiation on the surface layer of polyethylene samples, %-crosslinking and gel-fraction of test pieces shaved down to the various thickness after irradiation were measured by means of a vibrating reed method and a Soxhlet extractor respectively. And then, the values of %-crosslinking and gel-fraction on each layer were calculated. Although, at the internal layer, the linear relation between (1-δ)+√<1-δ> and 1/R has held as predicted by the theory of solubility, but approaching the surface, this linearity has not held for samples irradiated in air. Moreover Young's moduli on the surface have behaved non-lineally for the dose. These results, however, could be comprehended if the proportion of the main chain unit fractured were not proportional to the irradiation dose on the surface. The value of r/2c, the ratio of the unit fractured to one crosslinked reached 1.5 on the surface, about 3 times the value in the internal layer. Even on the layer near the surface where r/2c is lager than unity, a considerable degree of gel-formation took place. By using the data of Young's modulus and gel-fraction measurements, the initial number average molecular weight may be estimated.
社団法人日本材料学会の論文
1966-02-15