Thermo-oxidative stability of Nano-SiO2 /bismaleimide composite

Bismaleimides with three prepolymer molecular weights were synthesized and fabricated into graphite fiber reinforced nano-SiO₂ composites. Thermo-oxidative stability of these nano-composites under short-term isothermal exposure was studied. These composites were exposed to isothermal ageing for up to three hours. Dynamic mechanical properties and weight loss measurements indicate that for the composite prepared from prepolymers with lower molecular weight, activation energy for oxidative degradation is decreased, resulting in higher total weight loss in short-term isothermal aging due to non-reacted fragments remain entrapped within the network.