环境湿度对硅橡胶材料憎水迁移性的影响

Influence of Ambient Humidity on Hydrophobicity Transfer of Silicone Rubber Material

硅橡胶表面憎水性和其特有的憎水迁移特性,是硅橡胶复合绝缘子具有优异耐污闪能力的根本原因。环境湿度对硅橡胶材料的憎水迁移特性有较大影响,进而对复合绝缘子的污闪特性产生很大的影响,为此针对该问题开展了深入研究。利用饱和盐溶液法精确地控制小环境内的相对湿度,并采用静态接触角法测量污层表面的憎水性随迁移时间的变化过程。研究结果表明,在高湿环境下硅橡胶的憎水迁移特性显著变弱;对于IEC标准推荐的2种人工污秽,高岭土的吸湿能力强于硅藻土,环境湿度对表面惰性物质为高岭土时的憎水迁移特性影响较大;污秽中的可溶物质的吸湿性能也对硅橡胶材料的憎水迁移特性有很大影响,污秽中含有糖分和NaCl等盐类,会使硅橡胶的憎水迁移特性明显变差。

Hydrophobicity and the unique hydrophobicity transfer property of silicone rubber material are the basic reason why composite insulators can prevent pollution flashover.Hydrophobicity transfer property of silicone rubber material is greatly influenced by ambient humidity.To deeply investigate the problem mentioned above,ambient humidity was controlled using saturated salt solution method,and the hydrophobicity status of the pollution surface was measured using static contact angle method.The results show that hydrophobicity transfer speed of HTV（high temperature vulcanization）slows down in high humidity environment;as to the two recommended pollutants by IEC standard,the moisture absorption ability of kaolin is better than kieselguhr,ambient humidity has a great impact on the hydrophobicity transfer property when the inert material is kaolin;the moisture absorption ability of the soluble substance in the surface pollutants has a great impact on the hydrophobicity transfer property,when surface pollutants contain sugar and soluble salts like NaCl,the hydrophobicity transfer speed slows down and the stable contact angle is low.