Thermal degradation and physical properties of silicon carbide/carbon fiber/silicone rubber composites

초록

The silicone rubber has better thermal stability than other synthetic organic rubbers.[1] Silicone rubbers withstand high temperature atmosphere without a significant decrease in physical properties.[2] Effects of incorporation of carbon fiber (CF) and silicon carbide fiber (SCP) of different type into a high temperature vulcanization silicone rubber (HTV), poly(dimethylsiloxane) (PDMS) containing vinyl groups, on its mechanical and thermal degradation properties were explored. CF and SCP possessed good thermal stability.[3-4] Thermal stability and ablation properties of the silicone rubber composites containing CF and SCP were analyzed with the thermo-gravity analysis and the oxy-acetylene torch test. The time elapsed for the silicone rubber composites, loaded with a constant weight, to break up after the oxy-acetylene torch flame bursts onto the front surface of the specimens was used to evaluate the ablation properties simultaneously taking into consideration the mechanical strength of the char and the rate of decomposition. Tensile strength, elongation, and tear strength were measured with UTM. No remarkably increase in the tensile properties was observed as a result of the incorporation of CF and SCP. However, the failure time was prolonged considerably indicating that CF and SCP contributed to the enhancement of the ablation properties of the silicone rubber.