Study on powdering properties of silicone rubber insulating material in a coastal area

Abstract

Silicone rubber insulation materials are widely used in energy systems. The powdering of silicone rubber sheds is a newly discovered aging phenomenon in recent years, and there is no specific research. In this paper, the powder composition of the composite insulators in coastal areas was studied, and the powdering process of silicone rubber under a high humidity environment of salt fog was repeated in the laboratory. The results show that the powders can be divided into two types according to particle shape, element composition, and molecule groups: the inorganic filler and its dehydrated product and the small molecule siloxane after polymer aging fracture. The particle size of Type I of powder is 3∼8μm, and the particle size of Type II of small molecule siloxane is 0.3∼1.1μm. The surface hydrophobicity of the powdered sample in a salt-fog environment will deteriorate, and the static contact angle will decrease. However, the hydrophobicity will gradually recover after leaving the harsh environment. Powdering of composite insulator silicone rubber in coastal areas is a complex physical and chemical process caused by the combined action of electricity, heat, and moisture. During this, polymer molecular chains break, and fillers gradually precipitate, forming powders.