Preparation Of Composite Material Made By Room Temperature Vulcanizing Silicone Rubber And Phenolic Resin And Study Of The Relationship Between Properties And Structure

Ablation material is mainly used for thermal protection in the solid rocket motor insulation. When the solid rocket motor work, a high-temperature up to3000-3900K is produced. The role of insulation is to prevent the high-temperature gas burnning the shell, prevent the declining strength of the engine and endanger their structural integrity caused by overheating. At the same time, the insulation can also buffer the stress transfer between shell and propellant grain.This paper introduce the theory of ablation resistance and the development of ablation material at home and abroad.On the basis of this, composite material made by Room Temperature Vulcanizing (RTV) silicone rubber and phenolic resin are prepared. The relationship between properties and structure is discussed.At first, the effect of Fumed silica,TiO2, High silica fiber galss mesh and KH-550on mechanical properties,heat resistance and ablation property of RTV silicone rubber have been investigated. Results show that Fumed silica,TiO2and High silica fiber galss mesh can improve mechanical properties,heat resistance and ablation property of RTV silicone rubber.And then the effect of SiC,Cr2O3,ZrO2,TiO2,nami-TiO2, Al2O3and Fe2O3on the ablation property of RTV silicone rubber are discussed. Successfully,composite material based RTV silicone rubber with excellent ablation resistant property is made.And then,phenolic resin is modified by carboxyl terminated butadiene-acrylonitrile (CTBN) to improve its toughness. The effect of CTBN content on mechanical properties,heat resistance and ablation property of the modified phenolic resin aer discussed. Results show that the tensile strength and elongation at break of the phenolic resin increased with the content of CTBN. When the content of CTBN was10%,the mechanical properties reached the maximum. The results also show that chemical reaction happened between phenolic resin and CTBN and the heat resistance of modified phenolic resin decreased.