There is a growing interest in the use of silicone composite insulators for electrical power transmission and distribution applications. However, such materials are susceptible to degradation as they are exposed to electrical and environmental stresses during operating conditions. Therefore, it is crucial to gain a thorough understanding of the degradation mechanism through changes in the material structure that may provide insight into potential failures in the electrical grid. Attenuated total reflection Fourier transform infrared spectroscopy and two-dimensional correlation spectroscopy (2D-COS) were used along with contact angle measurements to characterize changes in silicone rubber samples from actual insulators subjected to tracking wheel testing. The results showed a decrease in absorbance of different infrared bands representing different functional groups, such as Si–O–Si, methyl functional groups, and both Al–O and hydroxyl groups of alumina trihydrate as a function of the number of tracking cycles. The sequence of changes in the functional groups was determined by 2D-COS as Al–O and OH followed by Si–O–Si polymer backbone modes, followed by polymer methyl side chains. An enhancement in the average contact angle with the number of tracking cycles revealed a concomitant increase in surface roughness with electrical tracking.

中文翻译：

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电痕引起的硅橡胶表面结构变化

人们对在电力传输和配电应用中使用有机硅复合绝缘子越来越感兴趣。然而，此类材料在工作条件下暴露于电气和环境应力时容易降解。因此，通过材料结构的变化来彻底了解退化机制至关重要，这可以深入了解电网中的潜在故障。使用衰减全反射傅立叶变换红外光谱和二维相关光谱 (2D-COS) 以及接触角测量来表征经过跟踪轮测试的实际绝缘体的硅橡胶样品的变化。结果表明，代表不同官能团（例如 Si-O-Si、甲基官能团以及三水合氧化铝的 Al-O 和羟基）的不同红外波段的吸光度随着跟踪循环次数的变化而降低。官能团变化的顺序由 2D-COS 确定，先是 Al-O 和 OH，然后是 Si-O-Si 聚合物主链模式，最后是聚合物甲基侧链。平均接触角随着电痕化循环次数的增加而增加，表明电痕化导致表面粗糙度随之增加。