The Importance of Hydroxyl Radicals as Intermediates in the Cross-linking of High Polymers by γ-Irradiation
The Importance of Hydroxyl Radicals as Intermediates in the Cross-linking of High Polymers by γ-Irradiation
复制标题
羟基自由基作为 γ 辐射交联高聚物中间体的重要性
作者：
Y. Tomoda;M. Tsuda
我们有辐照过的明胶薄膜（厚度0.5-1.0 mm）。剂量率为4.2 × 104 r. 10° C时为hr.−1。将该膜悬浮在含有氧气或氮气的带塞瓶中，或浸入充满该瓶的液体中。在照射膜之后，尝试在40° C下将其溶解在19倍于其自身重量的水中，并测量任何所得溶液的粘度。当在氧或氮气氛中进行照射时，或者当将膜悬浮在液体石蜡、苯、醚、环己酮、吡啶、丙酮或醇中时，即使当剂量超过1兆伦琴时，也没有观察到相对粘度的增加。然而，在水的存在下，明胶变成交联的，正如它仅仅通过用沸水处理而溶胀的事实所示。
WE have irradiated thin gelatin films (thickness 0.5–1.0 mm.) with cobalt-60 γ-rays at a dose-rate of 4.2 × 104 r. hr.−1 at 10° C. The film was either suspended in a stoppered bottle containing oxygen or nitrogen or immersed in a liquid which filled the bottle. After irradiation of the film, attempts were made to dissolve it in 19 times its own weight of water at 40° C., and the viscosity of any resultant solution was measured. No increase in relative viscosity was observed when the irradiation was carried out in an atmosphere of oxygen or nitrogen, or when the film was suspended in liquid paraffin, benzene, ether, cyclohexanone, pyridine, acetone or an alcohol, even when the dose exceeded 1 mega-roentgen. In the presence of water, however, the gelatin became cross-linked, as was shown by the fact that it was merely swollen by treatment with boiling water.