Study on the effect of aminosilane functionalized nanoclay on the curing kinetics of epoxy nanocomposites

The curing kinetics of epoxy nanocomposites prepared by incorporating pristine (P-MMT) and functionalized montmorillonite clay (S-MMT) was studied using non-isothermal differential scanning calorimetry (DSC) experiments. Loading of S-MMT in epoxy matrix resulted in the decrease of peak exotherm temperature (T-p) at all heating rates corroborating the enhanced curing reactions, when compared to neat or P-MMT filled epoxy system. The kinetic parameters of the curing processes of the neat, pristine and functionalized MMT filled epoxy were determined using isoconversional methods viz. Kissinger and Friedman methods. In comparison to P-MMT filled epoxy system, epoxy nanocomposites loaded with S-MMT showed lower activation energy (E-alpha) over the range of conversion (alpha) revealing the enhanced curing reactions in these system. Besides E-alpha, the overall order of reactions (m+n) does not vary significantly in comparison to neat or P-MMT loaded epoxy corroborating the fact that the curing mechanism is autocatalytic in nature. The predicted curves determined using the kinetic parameters fit well with the non-isothermal DSC thermograms revealing the proposed kinetic equation clearly explain the curing kinetics of the prepared epoxy nanocomposites. (C) 2012 Elsevier B.V. All rights reserved.