Abstract Polymeric electric insulators are an integral part of many electronic circuits and systems. Changes induced by an electric field can affect various mechanisms; including electrical polarisation and electromechanical properties. Changes in the dielectric material can be tracked using spectroscopic methods. This study has shown that analysing polypropylene under electric field stress using Raman spectroscopy in combination with principal component analysis allows small changes in the non-crystalline phase to be identified. We have observed that for polypropylene, vibrational motion and changes in conformation occur mostly within the tie molecules connecting the overall cluster network. Amorphous molecular chains in the spherulites were also found to orient and form into a smectic mesophase. These electromechanical changes at the micro- and macromolecular level were found to be generally reversible once the stress is removed. However, with increased aging, these changes may lead to adverse structural changes and thus, in the future, this information may be used to inform faults and defect detection within polymeric dielectric materials.

中文翻译：

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使用拉曼光谱研究聚丙烯中电场诱导的分子畸变

摘要 聚合物电绝缘体是许多电子电路和系统的组成部分。电场引起的变化会影响各种机制；包括电极化和机电特性。可以使用光谱方法跟踪介电材料的变化。该研究表明，使用拉曼光谱结合主成分分析在电场应力下分析聚丙烯可以识别非晶相的微小变化。我们已经观察到，对于聚丙烯，振动运动和构象变化主要发生在连接整个簇网络的连接分子内。还发现球晶中的无定形分子链定向并形成近晶中间相。一旦去除应力，这些微观和大分子水平的机电变化通常是可逆的。然而，随着老化的加剧，这些变化可能会导致不利的结构变化，因此，在未来，这些信息可用于告知聚合物介电材料内的故障和缺陷检测。