thermal stability of epoxy systems badge (n=0)/1,2-dch and badge (n=0)/ 1,2-dch/vinylcyclohexene dioxide

The thermal degradation of the epoxy system diglycidyl ether of bisphenol A (BADGE n=0)/1,2-diamine cyclohexane (DCH) containing different concentrations of an epoxy reactive diluent was studied by thermogravimetric analysis in order to determine the reaction mechanism of the degradation process and to compare it with the results for the same system without diluent. The value of the activation energy, necessary for this study, was calculated using various integral and differential methods. Values obtained using the different methods were compared to the value obtained by the Flynn-Wall-Ozawa"s method (between 193-240 kJ mol^-1 depending on the diluent concentration) with does not require a knowledge of the nth order reaction mechanism. All the experimental results were compared to master curves in the range of Doyle"s approximation (20-35% of conversion). Analysis of the results suggests that the reaction mechanism could be F₂, F₃, or A₂ type. This revised version was published online in July 2006 with corrections to the Cover Date.