Preparation of Polyurethane-Modified Silicone Rubber Insulating Coating and Its Application in 10 kV Overhead Bare Wire Wrapping

Abstract

Room-temperature vulcanized rubber is an excellent polymer material with excellent electrical insulation and mechanical properties, which can be used for field insulation of high-voltage bare wire. In this paper, a room-temperature cured coating material was prepared from α,ω-dihydroxy polydimethylsiloxane (PDMS), polyurethane-modified silicone material (PU-Si), and Methyltris(methylethylketoxime) silane (MOS). The study showed that the coating made by adding PDMS (70 g), PU-Si (30 g), CaCO3 (90 g), MOS (7 g), KH792 (5 g), and Mg(OH)2 (30 g) had a surface drying time of 19.1 min, tensile strength of 3.2 Mpa, volume resistivity greater than 4 × 1014 Ω·cm, breakdown voltage greater than 20 kV/mm, and flame retardant performance of the FV-1 level. The comprehensive performance of the insulation material meets the national standard of “Aerial insulated cables for rated voltage of 10 kV” (GB/T14049-2008), while the insulation material has been successfully applied to the overhead line renovation project of the State Grid Hubei Electric Power Company (Wuhan, China).