Study of thermomechanical properties of glycidoxypropyl trimethoxy silane functionalized nanosilica/amine terminated poly (butadiene-co-acrylonitrile) rubber modified novolac epoxy composites for high performance applications

Present study investigates the effect of functionalized fumed silica (f-silica) on the thermal; mechanical and thermomechanical properties of amine terminated polybutadiene-co-acrylonitrile rubber (ATBN) modified novolac epoxy resin. All the nanocomposites showed higher thermal stability as compared to the neat novolac epoxy. Maximum –55 ˚C increment in the peak degradation temperature was achieved in the nanocomposite containing 0.1 wt. % f-silica and 10 wt. % ATBN. Glass transition temperature of the nanocomposites was reduced as compared to neat novolac epoxy resin due to incorporation of ATBN. Thermomechanical analysis showed that crosslinking density of the ATBN/novolac epoxy composite was increased as compared to neat novolac epoxy, which was further reduced in the nanocomposites due to hardener capping effect of the f-silica. All the nanocomposites showed higher elongation at break as compared to neat novolac epoxy resin. Maximum –87 and 60% increment in tensile and flexural strengths were achieved in the nanocomposite containing 2 wt % f-silica and 10 wt. % ATBN. Impact strength of the nanocomposites was increased with increasing f-silica content. Preferential conglomeration of the f-silica nanoparticles was observed in the rubber phase which acted as the efficient energy absorption point during the impact testing.