室温硫化硅橡胶涂层厚度对电晕老化特性的影响

室温硫化硅橡胶(room temperature vulcanized silicone rubber, RTV)涂料凭借良好的憎水性和防污闪特性,广泛用于瓷、玻璃绝缘子表面。随着绝缘子运行时间的增加,RTV涂层会出现粉化、脱落、憎水性丧失等老化现象。现有研究对RTV涂层老化规律尚不明确,因此该文研究了交流电晕下RTV涂层厚度对其老化特性的影响。通过外观检查、憎水性测试、傅里叶变换红外光谱(Fourier transform infrared spectroscopy, FTIR)、扫描电镜(scanning electron microscope, SEM, SEM)和X射线光电子能谱(X-ray photoelectron spectroscopy, XPS)等试验,分析了不同厚度涂层宏观结构、微观形貌、憎水特性、化学组分的变化规律。结果表明:电晕老化后涂层表面析出黑色物质,出现明显分区结构,不同厚度涂层分别出现孔洞、裂纹和颗粒物等老化特征;涂层厚度为0.6～0.8 mm时,老化后的憎水性及迁移性能明显优于0.3～0.5 mm涂层;FTIR和XPS分析表明电晕老化形成的硅氧层厚度和...

Influence of the Thickness of Room Temperature Vulcanized Silicone Rubber Coatings on the Aging Characteristics of Corona

Room temperature vulcanized silicone rubber(RTV) coatings are widely used in porcelain and glass insulators due to their good hydrophobicity and anti-pollution flashover performance. With the increase of insulator operating time, the electrical performance of RTV coatings will be decreased by aging phenomena such as pulverization, shedding, and hydrophobicity losing. In current study, the aging mechanism of RTV coatings has not been clearly researched. Therefore, we investigated the influence of coating thickness on its aging characteristics under AC corona. The macrostructure, microstructure, hydrophobicity and chemical composition of the coatings with different thickness were analyzed from the following aspects, such as, appearance examination, hydrophobicity test, Fourier transform infrared spectroscopy(FTIR), scanning electron microscopy(SEM), and X-ray photoelectron spectroscopy(XPS) tests. The results show that, after corona aging, a black material precipitates on the coating surface and shows obvious partition structure. At the same time, holes, cracks, particles and other aging characteristics of coatings with different thickness can be observed. The hydrophobicity and migration properties of coatings with 0.6~0.8 mm thickness are much better than those with 0.3~0.5 mm thickness. FTIR and XPS results show that the silicon oxide layer thickness and the broken chain layer thickness will decrease with the increase of coating thickness. The high oxidation state of silicon content of 0.6 mm coating is obviously higher than that of 0.3 mm coating. The influence of corona aging on the physical and chemical properties of the coating decreases with the increase of coating thickness.