硅橡胶绝缘子粉化层憎水性变化的研究

Study on Hydrophobicity Variation of Silicone Rubber Insulator Powder Layer

硅橡胶绝缘子运行后会逐渐老化,伞裙表面出现粉化层。为研究粉化层对硅橡胶绝缘子表面憎水性的影响,通过红外光谱(IR)、扫描电镜(SEM)等手段对现场取回的硅橡胶绝缘子进行研究,测试硅橡胶绝缘子粉化层的微观结构和化学成分,进一步分析粉化层表面憎水性变化的原因。结果表明:绝缘子粉化层表面憎水性良好,但去掉粉化层后绝缘子表面憎水性明显下降。通过IR和SEM发现绝缘子的粉化层表面老化降解程度严重,硅橡胶材料主链上的分子键断裂,粉化层物质颗粒之间结构疏松,分子间相互作用力小,观察其微观形貌发现大量孔隙。因此水分不易附着在绝缘子伞裙表面,使运行老化后硅橡胶绝缘子表面仍具有良好的憎水性。

The silicon rubber insulator will deteriorate gradually after operating,and there is powder layer on the surface of insulator shed.In order to study the influence of powder layer on the surface hydrophobicity of silicone rubber insulator,the silicone rubber insulators in service were studied by infrared spectrum(IR)and scanning electron microscope(SEM).The microstructure and chemical compositions of the powder layer were tested,and the reasons of surface hydrophobicity variation were analyzed.The results show that the insulator with powder layer has good surface hydrophobicity,but the surface hydrophobicity decreases obviously after removing the powder layer.The IR and SEM results indicate that the surface of insulator with powder layer is severely aged,the molecular bonds on the main chain of silicone were broken,the powder layer is loose,the intermolecular forces were small,and there are many pores on the power layer.Therefore,moisture is not easy to attach to the surface of insulator sheds,and the aged silicone rubber insulators still have good surface hydrophobicity.