The thermal degradation of the epoxy system consisting of diglycidyl ether of bisphenol A (BADGE, n=0)-1,2-diaminocyclohexane (DCH) containing calcium carbonate filler is studied by thermogravimetric analysis to determine the reaction mechanism of the degradation process. The value of the activation energy, which is necessary for this study, is calculated using various integral and differential methods. The values obtained using the different methods are compared to the value obtained by Kissinger's method (234.84 +/- 15.12 kJ/mol), which does not require knowledge of the n-order value of the reaction mechanism. All the experimental results are compared to master curves in the range of Doyle's approximation (5-35% of conversion). The analysis of the results suggests that the reaction mechanism is a sigmoidal A(2) type. The thermodegradation mechanism is similar to that found for the same epoxy system without additives. However, for this last system the sigmoidal mechanism is an A(4) type.