Preparation Of Carbon Fiber/Silicone Prepreg And Improvement On Heat-resistant Of Silicone

The silicone is widely used in the field of aerospace because of its excellent comprehensive properties such as heat-resistant qualities and processing properties. As a kind of preparation of intermediate for composite materials, using prepreg could improve the production environment and stability of composite properties of the composite. At present, there is no related study for silicone. To meet the requirements of thermal stability of the composite materials used in aerospace, it is necessary to improve the heat-resistant properties of silicone composite.The properties of prepreg were detected by changing process parameters. The best rolls distance is 1.1mm. The optimum group of temperature and time which satisfied the viscidity and liquidity of prepreg is 110℃ and 210 s respectively. After twice dipping treatment for prepreg could get the best properties. And the best storage time for prepreg is 26 days.The resin curing process effect of methyl phenyl silicone after adding carborane was analyzed through DSC. The results showed that the initial curing temperature decreased from 149.1℃ to 112.5℃ after adding carborane, the peak curing temperature decreased from 180.3℃ to 144.5℃, and termination curing temperature decreased from 208.5℃ to 176℃. At the same time, the curing activation energy of methyl phenyl silicone decreased from 50.53KJ/mo to 32.44KJ/mol, making the curing of methyl phenyl silicone easier.The thermal properties of methyl phenyl silicone after adding carborane was deteceted by TG. The thermal decomposition temperature and decomposition activation energy of methyl phenyl silicone was promoted obviously, while the losing weight rate was reduced after adding carborane.The composite materials properties were studied, including the interface shear strength and bending strength. There is no change in interface shear strength and bending strength of the methyl phenyl silicone after adding carborane at normal temperature. When the temperature raisedd to 300℃, the interface shear strength and bending strength of the composite materials remained unchanged. When the temperature raised to 500℃, the interface shear strength and bending strength retention of composite materials increased remarkablely. Thus, adding carborane could improve the high temperature mechanical properties of the methyl phenyl silicone composite materials significantly.