Effect of temperature on dielectric and mechanical properties of methyl silicone resin composites

The tensile strength and dielectric property of methyl silicone resin composites under different temperatures were investigated. The heat resistance and chemical structure change of methyl silicone resin under high temperature were analyzed by means of IR and TG, and chemical composition and structure of the composite surface before and after ablation were characterized by means of SEM and EDS. The results show that the dielectric constant (Ε) and the tangent (tanδ) of loss angle of the composites increase with temperature from room temperature to 1200°C; with increase of temperature, decomposition of methyl silicon resin speeds up, its chemical structure changes, and the tensile strength of the composites reduces; with increase of temperature, free carbon affecting dielectric property is generated in silicone resin, which influencs the transmission of electromagnetic wave in methyl silicone resin composites.