The effect of curing temperature on fracture energy of nanosilica filled epoxy with different particle sizes

Epoxy toughening is very important in industry, because high brittleness and low fracture energy. In this work different toughening techniques was used for epoxy curing system. The techniques include change of the curing temperature and simultaneous addition of silica nanoparticles on curing system. The glass transition temperature of epoxy with this curing system is approximately 118 , if the curing temperature is too closer to glass transition temperature then curing is complete, So tensile modulus and other properties such as strength is increased; In this work curing temperature was changed from 105 to 90 . While it was just pure epoxy to be tested, tensile modulus decrease and fracture energy increases, as result imperfect curing at 90 . But addition of nano-particles to the curing system increased tensile modulus in both temperatures curing system, this increased in both curing system is equal while the equal nominal surface of the nanoparticles used. On the other hand toughness and fracture energy in both curing system increased with increased nominal surface of nanoparticles when nanosilica is used, this raise in the fracture toughness at curing temperature of 90 is always greater than from the fracture toughness at curing temperature of 105 . In generally seen curing at 90 and increase in the nominal surface of nano- particles which were strongly increased fracture toughness, and modulus. The fundamental mechanisms that are effective in increasing the toughness of nano composites, they are used to analyzing the increase in fracture toughness of nanocomposites.