The interface between silicone rubber (SR) and fiber reinforced plastic (FRP) is a weak point in composite insulator, which is easy to be affected by moisture. However, the corresponding evaluation methods and detection means are not complete yet. Based on the newly proposed method for measuring the interface resistivity with a four-electrode system, the influence of liquid type, filler and coupling agent on the interface resistivity are studied in this paper. It is found that the interface resistivity reduced by 2–4 orders of magnitude after permeation by deionized water, saline and low concentration nitric acid, but the variation trend of interface resistivity is specific when permeated in high concentration of nitric acid solution (1 mol/L). The experimental results of samples with and without silicone coupling agent (SCA) are compared and it is found that the interface without silane coupling agent is easier to be penetrated by liquid, and the change of interface resistivity is more obvious. Besides, the influence of moisture-sensitive Alumina Tri-hydrate and SiO2 fillers, which could provide paths for water and hydrated ions to permeate, on interface resistivity are analyzed. The experimental results are of great significance for the selection of the appropriate formula system and the prevention of liquid penetration for composite insulators.

中文翻译：

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液体类型、填料和偶联剂对硅橡胶与纤维增强塑料界面电阻率的影响

硅橡胶（SR）与纤维增强塑料（FRP）的界面是复合绝缘子的薄弱点，容易受潮。然而，相应的评价方法和检测手段尚不完善。本文基于新提出的四电极系统界面电阻率测量方法，研究了液体类型、填料和偶联剂对界面电阻率的影响。研究发现，去离子水、生理盐水和低浓度硝酸渗透后界面电阻率降低2-4个数量级，但在高浓度硝酸溶液（1 mol/ L)。对比加入和不加入有机硅偶联剂（SCA）样品的实验结果，发现未加入硅烷偶联剂的界面更容易被液体渗透，界面电阻率的变化更为明显。此外，分析了水分敏感的三水合氧化铝和SiO2填料对界面电阻率的影响，这些填料可以为水和水合离子渗透提供路径。实验结果对选择合适的配方体系和防止复合绝缘子渗液具有重要意义。可以为水和水合离子渗透提供路径，分析界面电阻率。实验结果对选择合适的配方体系和防止复合绝缘子渗液具有重要意义。可以为水和水合离子渗透提供路径，分析界面电阻率。实验结果对选择合适的配方体系和防止复合绝缘子渗液具有重要意义。