Improving the Thermal Insulation and Ablative Properties of Liquid Silicone Rubber by Adding Titanium Dioxide

Abstract

The development of aerospace industry advances the design and preparation of high-performance flexible ablation-resistant and thermal insulation materials. In this work, a simultaneous improvement of thermal ablative and erosion resistance, thermal insulation, and char quality of epoxy modified vinyl silicone rubber (EMVSR)-based composites was achieved by adding a small amount of titanium dioxide (TiO₂). The results showed that TiO₂ acted as a heat shielding agent by reflecting dissipated heat and catalyzing the graphitization as well as reinforcing the char layer through co-caramelization reaction. The linear ablation rate and back-face temperature of EMVSR with 5 phr TiO₂ were reduced by 21.5% and 16.1% when compared with the control sample (without TiO₂) at a heat flux of 4 MW/m². Moreover, the emissivity, thermal insulation, surface temperature, as well as the densification of char layer were improved by adding TiO₂. This work provided a facile method to develop high-performance flexible thermal ablative materials for thermal protection purposes in the aerospace and fire protection sectors among others.