Curing studies of epoxy resin by 4,4′‐diaminoazobenzene as curing agent reinforced with nanosilica and nanoclay particles along with impact resistance and thermal evaluation

The effects of nanosilica (NS) and nanoclay (NC) particles as catalyst on the mechanism and kinetic parameters of cure reaction of DGEBA/4,4′‐diaminoazobenzene (DAAB) systems were studied. The kinetics parameters were obtained from nonisothermal differential scanning calorimeter data using the Kissinger, Ozawa, and isoconversional equations. The exothermic peak was shifted toward lower temperatures in DGEBA/DAAB/nanoparticle (NP) systems with increasing amount of the NP. However, the existence of NS and NC particles with hydroxyl groups in the structure in the mixture of DGEBA/DAAB catalyzes the cure reaction and increases the rate constant. The activation energy of cure reaction of DGEBA/DAAB systems, obtained from three methods, was in good agreement and showed a decrease when NPs were present in the mixture. The morphology of nanocomposite and dispersion of NPs in the composites was also observed using scanning electron microscopy. The impact resistance and thermogravimetric analysis of cured epoxy systems were also reported. POLYM. COMPOS., 31:1465–1473, 2010.