Degradation of an Amine‐Based Epoxy Resin–Kinetics Analysis and Chemical Behavior

ABSTRACT This study investigates the thermal decomposition of a crosslinked epoxy resin system based on diglycidyl ether of bisphenol A (DGEBA) and diamines in both inert and oxidative atmospheres. First, kinetic modeling of the degradation process was performed. Under nitrogen, the reaction was described by two successive steps with activation energies of 157 kJ/mol (first step) and 208 kJ/mol (second step). In air, a five‐step model was applied with activation energy varying between 120 and 225 kJ/mol, depending on the step. Gaseous decomposition products were analyzed using a Fourier‐transform infrared (FTIR) spectrometer and a gas chromatograph–mass spectrometer (GC‐MS), both coupled with a thermobalance. The results indicate that the surrounding atmosphere had only a minor impact on the nature of the degradation products, which predominantly included water, phenol, phenolic derivatives, and ammonia. However, in addition to the products detected in nitrogen, carbon dioxide, and carbon monoxide were additionally detected in the oxidative environment.