Synthesis and characterization of high performance polymeric hybrid siliconized epoxy composites for aerospace applications

Two different types of hybridized siliconized epoxy matrix systems have been developed using two commercially available (CIBA-GEIGY) epoxy resins with hydroxyl terminated polydimethyl siloxane. The percentage siloxane content in the epoxy systems have been optimized based on the physico-chemical, electrical, mechanical and thermal properties. The matrix resins are cured using aliphatic amine (HY951), aromatic amine (HT972) and polyamidoamine (HY840) from CIBA-GEIGY and gamma-aminopropyltriethoxysilane (A-186, Union Carbide). The optimized siliconized epoxy materials are filled with additives like fillers (SiO2, BaSO4 and TiO2), plasticizer (dioctylphthalate), flame retardant (tris (2-chloropropyl) phosphate) and reinforced with E-glass fiber and Kevlar-49 and their effect on electrical and mechanical properties are studied. Introduction of siloxane units (silicone) in to the epoxy systems enhances dielectric properties with little loss of mechanical properties. Additives alter the electrical and mechanical characteristics based on their nature and concentration. Reinforcements enhanced the electrical and mechanical behavior to an appreciable extent. Data resulted from the studies reveal that the siliconized epoxy matrix systems reinforced with E-glass fiber and Kevlar-49 can be used in the filament wound liquid pressure vessels in the field of aerospace and other high performance engineering applications.