硅灰石对陶瓷化硅橡胶性能的影响

研究了硅灰石长径比和用量对硅橡胶力学性能、阻燃性能、热稳定性和高温烧蚀后烧结体弯曲强度的影响，并使用扫描电镜(SEM)观察烧结体断面的微观结构。结果表明，加入硅灰石的硅橡胶能够在高温烧蚀下形成坚硬、致密的陶瓷状壳体，添加普通硅灰石的硅橡胶在高温烧蚀后形成的烧结体的弯曲强度较大。添加针状硅灰石的硅橡胶的阻燃性能和热稳定性更好，随着针状硅灰石添加量的增大，硅橡胶的氧指数、分解温度和残余物质量增加，分解速率降低；针状硅灰石添加量为60份时，硅橡胶的氧指数为36.7，初始分解温度为514oC，最快分解速率为2.48%/min，残余物质量为78.6%。;The effect of draw ratio and content of wollastonite on mechanical property，flame retardant property，thermal stability of silicone rubber and bending strength of sintered body after ablation at high temperature were investigated. The fracture surface of sintered body was observed by scanning electron miscroscope (SEM). The results showed that the silicone rubber added with wollastonite could form a hard，dense ceramic shell after ablation at high temperature；the sintered body formed by the silicone rubber added with common wollastonite had higher bending strength. The silicone rubber added with acicular wollastonite had preferable flame retardant property and thermal stability. With the increase of acicular wollastonite，the oxygen index，decomposition temperature and residue yield of silicone rubber increased while the decomposition rate decreased. When the addition of acicular wollastonite was 60 phr，the oxygen index of the silicone rubber was 36.7，temperature of initial decomposition was 514oC，highest degradation rate was 2.48%/min and residue yield was 78.6%