Thermal behavior of epoxy resin cured with aromatic dicarboxylic acids

The curing kinetics and thermal properties of diglycidyl ether of bisphenol A crosslinked with two aromatic diacids were studied using non-isothermal differential scanning calorimetry and simultaneous TG/FTIR/MS analysis. In the crosslinking of the epoxy resins with anhydrides, there is an intermediate stage resulting acids, while the direct use of acids eliminate this phase. The kinetic parameters of the curing reactions were calculated using Kissinger, Flynn-Wall-Ozawa methods and also the multivariate nonlinear regression method included in Netzsch Thermokinetics software. The kinetic parameters and the thermal degradation mechanisms for the crosslinked resins were determined using the same software. The thermal degradation processes occurred in three steps, depending on the chemical structure of the samples. The thermal lifetime of the crosslinked resins was also calculated.