Durability of Irradiated Polymers in Solid-Polymer-Electrolyte Water Electrolyzer
Durability of Irradiated Polymers in Solid-Polymer-Electrolyte Water Electrolyzer
复制标题
固体聚合物电解质水电解槽中辐照聚合物的耐久性
DOI：
10.1080/18811248.2004.9726431
复制
发表时间：
2005
影响因子：
1.2
通讯作者：
M. Tamada
中科院分区：
文献类型：
--
作者：
Y. Iwai;T. Yamanishi;M. Nishi;T. Yagi;M. Tamada
通过500kGy射线辐照试验，研究了辐照有机聚合物在固体-聚合物-电解液电解槽中的耐久性。离子交换膜(Nafion®)的抗张强度和离子交换能力在850kGy时没有严重恶化。垫片材料(Aflas®)的抗拉强度在500 kGy时也没有观察到严重损坏。绝缘体材料(PFA和FEP)分别在200kGy和300kGy时失去抗拉强度。根据以上结果，我们可以肯定地说，在用聚酰亚胺树脂取代PFA和FEP的情况下，电解槽的辐照条件可以达到500kGy左右，这种聚酰亚胺树脂具有良好的耐辐照性能。两种降解机制被认为是辐射的影响。一种是伽马射线对链和支链的直接降解。另一种是激进分子的攻击造成的退化。结果表明，自由基对膜的降解作用不占优势。此外，观察到氧气对降解有很大的影响。水中易于测量的溶解氟的量与抗拉强度和离子交换容量密切相关。因此，可以通过监测水中溶解氟的量来评价离子交换膜的降解程度。针对不同辐射源对离子交换膜降解机理的不同，提出了以抗张强度、离子交换量和溶解氟量的组合作为劣化指标。
The durability of irradiated organic polymers in solid-polymer-electrolyte water electrolyzer was investigated by gamma-ray irradiation tests around 500 kGy. Serious deteriorations for the tensile strength and ion exchange capacity of the ion exchange membrane (Nafion®) were not observed up to 850 kGy. No serious damage was also observed for tensile strength of the gasket materials (Aflas®) up to 500 kGy. The insulator materials (PFA and FEP) lost their tensile strength at 200 kGy and 300 kGy, respectively. From the above results, we can safely say that the electrolysis cell could be used up to around 500 kGy of irradiation conditions in the case where PFA and FEP are replaced by the polyimide resin which durability against the irradiation is well demonstrated. Two degrading mechanisms were supposed as the effect of irradiation. One is the direct degradation of the chain and branch by gamma-ray. The other is degradation by the attack of radicals. It was demonstrated that the effect of radicals on degradation of the membrane was not dominant. In addition, oxygen was observed to have a large influence on degradation. The quantity of dissolved fluorine in water that could be measured easily was found to correlate closely with tensile strength and ion exchange capacity. Hence, it is possible to evaluate the degradation of ion exchange membrane by monitoring the quantity of dissolved fluorine in water. Concerning the difference of degrading mechanism of the ion exchange membrane due to irradiation source, the combinations of tensile strength, ion exchange capacity and quantity of dissolved fluorine are proposed as deterioration indexes.