复合绝缘子用高温硫化硅橡胶老化图谱绘制方法

目的 研究高温硫化硅橡胶材料在户外不同环境因素作用下的老化规律与相应的老化图谱绘制方法。方法 通过静态接触角、邵氏硬度法测量硅橡胶老化前后的宏观特性，利用扫描电子显微镜(SEM)观察其表面微观形貌变化，通过倒易法则、阿伦尼乌斯公式以及叠加法则构建紫外光和温度双因素老化模型，并结合人工与自然老化试验硬度测试结果，对比不同地点的加速因子，初步建立老化速率图谱绘制方法。结果 随着紫外老化以及热老化时间的增加，硅橡胶的憎水性先增强、后逐渐变差，硅橡胶硬度以幂函数形式增加。SEM结果表明，硅橡胶表面发生降解。结合表面硬度特性可以较好地表征材料的老化状态，并用于老化图谱绘制，老化模型结果与自然试验结果一致。结论 硅橡胶老化图谱可以较好地预测各地不同环境下硅橡胶的老化状态，帮助电网制定运维策略，降低成本。

Approach to Draw the Aging Map of High Temperature Vulcanized Silicone Rubber for Composite Insulator

The work aims to study the aging principle of high temperature vulcanized silicone rubber under different outdoor environmental conditions and the corresponding approach to draw the aging map. The macroscopic properties of silicone rubber before and after aging were measured by static contact angle and shore hardness method, and the microscopic morphology of the surface was studied by scanning electron microscope (SEM). The reciprocity law, Arrhenius equation and superposition law were adopted to build the two-factor aging model combining ultraviolet and temperature. According to the results of shore hardness after artificial and natural aging tests, the acceleration factors in different sites were compared, and the approach to draw the aging rate map was preliminarily established. With the increase of UV aging time and thermal aging time, the hydrophobicity of silicone rubber increased firstly and then decreased gradually and the shore hardness of silicone rubber increased by a power function. SEM results indicated the degradation of silicone rubber surface. The surface hardness characteristics could be used to characterize the aging state of materials well and draw aging map. The results of aging model were consistent with those of natural tests. The silicone rubber aging map can better predict the aging state of silicone rubber in different environments and help power grid companies to formulate operation and maintenance strategies and reduce costs.