Study on the effect of poly(oxypropylene)diamine modified organic montmorillonite on curing kinetics of epoxy nanocomposties

The effects of poly(oxypropylene) diamine modified organic montmorillonite (modified MMT) on the curing kinetics of epoxy (EP) were investigated by means of differential scanning calorimetry (DSC). The curing kinetic parameters of pure epoxy and the EP/modified MMT were obtained by Kissinger method and autocatalytic model. The in total heat of reaction ΔH, peak temperature Tp, activation energy Ea and the overall order of reaction m + n were enhanced due to the incorporation of modified MMT in the epoxy. Results on the calculation of EP/modified MMT revealed the activation energy was much higher at the beginning and decreased all the way in the curing process, while in the neat epoxy, the variation of activation energy is limited. Comprehensive kinetic analyses indicated that the incorporation of modified MMT brought in an effect of inhibition on curing process especially for MMT with disordered and puffed clay sheets and the possible curing mechanism and reaction pathways were proposed to provide a reasonable explanation.