非典型污秽环境下高温硫化硅橡胶的吸水性

高温硫化硅橡胶伞裙和护套吸水、吸湿后的介质损耗发热会导致硅橡胶复合绝缘子出现局部温度升高现象,硅橡胶的吸水、吸湿受到多种因素的影响。为此利用称重法研究非典型污秽(氢氧化钠、葡萄糖和硫酸钙)溶液浸渍时无机填料特性、温度、溶液浓度和拉应变对高温硫化硅橡胶吸水性的影响,以及利用现代材料分析方法研究这些污秽溶液的浸渍对硅橡胶理化性能的影响。研究结果表明:无机填料颗粒表面的憎水性改性有助于减少硅橡胶在污秽溶液中的吸水,使拉应变加速并增加了硅橡胶在污秽溶液中的吸水,高温污秽溶液的浸渍降低了硅橡胶的活化能及其热稳定性。该研究补充了高温硫化硅橡胶在非典型污秽环境下的吸水性变化规律。

Water Absorptivity of High-temperature Vulcanized Silicone Rubber Under Atypical Contaminants

The dielectric loss heating of high-temperature vulcanized silicone rubber sheds and sheaths after water and moisture absorption may lead to the occurrence of local temperature rise in a silicone rubber composite insulator. The water and moisture absorptivity of a silicone rubber may be influenced by multiple factors. Consequently, we studied the influences of inorganic filler property, temperature, solution concentration and tensile strain on the water absorptivity of the silicone rubber immersed in the aqueous solutions of atypical contaminants, including sodium hydroxide, glucose and calcium sulfate, by using the weight method, and studied the effects of the solution immersion on the physicochemical properties of silicone rubber by using modern methods for material analysis. Results indicate that the hydrophobicity treatment on an inorganic filler surface weakens the water absorption of the silicone rubber immersed in the solutions, the tensile strain accelerates and increases its water absorption, and the high-temperature solution immersion lowers its activation energy and thermostability.The variation law of water absorptivity of the high temperature vulcanized silicone rubber in the atypical contaminants was supplementarily studied.