To clarify the degradation of the electrical insulation ability of polymeric materials at the molecular level, the effects of an external electric field on the rupture of molecules were evaluated using quantum chemical calculations. Two molecular models were evaluated with the aim of elucidating the physicochemical background of realistic insulation deterioration factors, namely, the effect of oxidation and impurities. The first model was used to evaluate the effect of oxidative degradation of alkane molecules on the C–C bond; maximum rupture force of the C–C bonds of decane and 4-decanone were compared, and it was found to decrease by approximately 13.8 %. It was also clarified that the maximum rupture force changes depending on the applied direction of the external electric field. The second model was used to examine the effect of an external electric field on the decomposition of dicumyl peroxide, which is a cross-linking agent for cross-linked polyethylene. In the decomposition process of dicumyl peroxide, the rupture of cumyl alcohol was found to be strongly influenced by an external electric field. Because the decomposition of cumyl alcohol involves dehydration, it is likely to induce the initiation and propagation of water trees in polyethylene. Therefore, it is important to remove the cumyl alcohol before applying a high voltage.

为了阐明聚合物材料在分子水平上电绝缘能力的退化，使用量子化学计算评估了外部电场对分子破裂的影响。为了阐明现实绝缘劣化因素的物理化学背景，即氧化和杂质的影响，对两个分子模型进行了评估。第一个模型用于评估烷烃分子氧化降解对 C-C 键的影响；比较了癸烷和 4-癸酮的 C-C 键的最大断裂力，发现其降低了约 13.8%。还阐明了最大断裂力根据外部电场的施加方向而变化。第二个模型用于检查外部电场对过氧化二异丙苯分解的影响，过氧化二异丙苯是一种交联聚乙烯的交联剂。在过氧化二异丙苯的分解过程中，发现异丙醇的破裂受外部电场的强烈影响。由于枯醇的分解涉及脱水，因此很可能在聚乙烯中诱导水树的萌生和繁殖。因此，在施加高电压之前去除枯醇是很重要的。由于枯醇的分解涉及脱水，因此很可能在聚乙烯中诱导水树的萌生和繁殖。因此，在施加高电压之前去除枯醇是很重要的。由于枯醇的分解涉及脱水，因此很可能在聚乙烯中诱导水树的萌生和繁殖。因此，在施加高电压之前去除枯醇是很重要的。