聚硅倍半氧烷改性光固化硅橡胶绝热耐烧蚀材料

Based on the thiol-ene chemical crosslinking system, silicone rubber insulation materials were prepared by room temperature light curing. The effects of new ablative fillers, octaphenyl silsesquioxane (OPS) and octavinyl silsesquioxane (OVP), on the properties of thiol-ene crosslinked silicone rubbers were studied. The silicone rubbers were systematically analyzed by TGA, mechanical test, oxyacetylene ablation, limiting oxygen index (LOI), cone calorimetry and SEM. The results show that OPS and OVP can improve the thermal stability and ablation resistance of silicone rubbers, but have some influence on the mechanical properties. The silicone rubber modified with OVP shows a better ablation resistance, and the ablation rate of the silicone rubber wire containing 15 phr OVP is 0.121 mm/s, which is 84.8% lower than that of pure silicone rubber. The addition of OPS and OVP can significantly prolong the ignition time (TTI) and reduce the peak value of heat release rate (P-HRR). The carbon layer of the modified silicone rubber is more dense after combustion, and the effect of OVP is better than OPS. Therefore, polysilicon sesquioxane has great application value in the field of silicone rubber thermal insulation and ablation resistant materials.