THERMAL OXIDATIVE-DEGRADATION OF EPOXY-RESINS - EVALUATION OF THEIR HEAT-RESISTANCE USING INVARIANT KINETIC-PARAMETERS

The thermal degradation of two epoxy resins was studied using a noniso thermal thermogravimetric technique. This work applies the invariant k inetic parameter (IKP) method in order to describe the degradation of the resins. The kinetic parameters (pre-exponential factor and activat ion energy) are independent of the experimental conditions and are com puted without any hypothesis on the form of the kinetic degradation fu nction. Moreover, the method allows us to compute the distribution of the probabilities associated to kinetic functions and to predict the d egradation mode of the material. The kinetic model which best describe s the decomposition of epoxy resins is that corresponding to a diffusi on mechanism. Invariant activation energies of the degradations of TGD DM/DDS and TGDDM/DDA systems allows the comparison of their heat resis tances in air and shows that the resin cured using the aromatic diamin e is the more stable.