Abstract The effect of electrical stress on glass fiber reinforced polymer under wet condition has been investigated in the present study. A specially designed and fabricated test setup was used through which the current passing through the GFRP rod during the test was recorded. Based on the changes in morphology of GFRP rod surface and development trend of current, the degradation process of GFRP rod caused by electrical stress under wet condition was divided into four consecutive stages, namely degradation inception stage, hydrolysis stage, carbonization stage and breakdown stage. Scanning electron microscopy (SEM), Fourier transform infrared (FTIR), thermogravimetric analysis (TGA) and X-ray Photoelectron Spectroscopy (XPS) analyses were employed to provide the physical and chemical properties of GFRP at different stages. The results showed that the degradation process of GFRP caused by electrical stress under wet condition progressively developed in the form of degraded channel, in which the epoxy resin matrix deteriorated significantly. The occurrences of hydrolysis, oxidation, pyrolysis and carbonization of epoxy resin matrix could be observed sequentially in the degradation process of GFRP during the test. With the development of the degradation process of GFRP, the content of epoxy resin matrix continued to decrease and the relative content of highly oxidized carbons (C-O, C=O and O-C=O) in epoxy resin matrix on GFRP surface increased before the carbonization process and then decreased in the carbonization process. The present study is helpful for better understanding of the electrical performance of GFRP used in high voltage composite insulator as well as in other electrical applications.

中文翻译：

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潮湿环境下电应力对高压复合绝缘子用玻璃纤维增​​强聚合物的影响

摘要 本研究研究了湿条件下电应力对玻璃纤维增​​强聚合物的影响。使用专门设计和制造的测试装置，记录测试期间通过 GFRP 棒的电流。根据GFRP棒表面形貌的变化和电流的发展趋势，将湿条件下电应力引起的GFRP棒降解过程分为四个连续的阶段，即降解开始阶段、水解阶段、碳化阶段和击穿阶段。采用扫描电子显微镜 (SEM)、傅里叶变换红外 (FTIR)、热重分析 (TGA) 和 X 射线光电子能谱 (XPS) 分析来提供不同阶段 GFRP 的物理和化学性质。结果表明，湿条件下电应力引起的GFRP降解过程以降解通道的形式逐渐发展，其中环氧树脂基体显着恶化。试验过程中，在GFRP的降解过程中，可以观察到环氧树脂基体的水解、氧化、热解和碳化依次发生。随着GFRP降解过程的发展，环氧树脂基体含量不断降低，碳化过程前GFRP表面环氧树脂基体中高氧化碳（CO、C=O和OC=O）的相对含量增加然后在碳化过程中减少。