Obtaining and Thermophysical Properties of Thermal Liners Based on Silicone Elastomer Filled with Hexagonal Boron Nitride

Basic thermophysical and electric-insulation properties of composite film materials based on silicone and hexagonal boron nitride with a content of the heat-conductive filler as high as 46 vol.% have been described. The maximum thermal conductivity was 6 W/(m·K) at a thermal-conductivity anisotropy of about 2.0. The obtained materials possessed a high bulk electrical resistance at a constant current of >10⁹ Ω·cm. It has been shown that in the target interval of operating conditions, the thermal diffusivity of a material at different contents of the filler depends weakly on temperature, and the thermal decomposition of the binder begins at a temperature no lower than 400°C. It has been established that the cross-linking of silicone under pressure may noticeably (up to 20%) increase the composite’s thermal conductivity and its anisotropy.