Study on Modification of Room Temperature Vulcanized Silicone Rubber by Microencapsulated Phase Change Material

Abstract

Ice coating seriously threatens the safe operation of the power system. Some electrical equipment made of vulcanized silicone rubber also suffered from ice hazards. Vulcanized silicone rubber has poor thermal insulation properties under low temperatures, which causes its surface to freeze quickly. To improve its thermal insulation properties, room temperature vulcanized silicone rubber (RTV) was mixed with microencapsulated phase change material (MEPCM) to increase its latent heat. As the ambient temperature decreases, the latent heat in the modified RTV will be released to keep it around the phase transition temperature (PCT). MEPCM having a silica shell and n-tetradecane nucleus are prepared by in-situ interfacial polymerization. Tests analysis shows that the freezing temperature of MEPCM is 2.3°C, and the latent heat is 130.8 J/g. The ratio of MEPCM to RTV, latent heat and PCT determine the thermal insulation performance of silicone rubber at low temperatures. When the mass ratio of microcapsules and silicone rubber is 1:5, the modified RTV can keep the temperature above 0°C for about 6 minutes at an ambient temperature of -10°C. The addition of MEPCM reduces the self-cleaning ability of RTV, but the self-cleaning coefficient is still greater than 85%, showing has a good self-cleaning ability. MEPCM with PCT close to 0°C has certain research significance in the field of anti-icing and thermal energy storage.