| Abstract: | A tetraglycidyl 4,4′-diaminodiphenylmethane (TGDDM) type tetrafunctional epoxy resin containing carbon powders was cured with the stoichiometric amount of a tetrafunctional curing agent, namely m-phenylenediamine (mPDA). Carbon powders were oxidised with air or nitric acid. The influence of carbon powders on curing of the resin was followed by dynamic mechanical analysis, Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). Gelation and vitrification times were determined as a function of the variations of dynamic properties. The evolution of viscoelastic modulus during curing of the different mixtures showed that untreated carbon powder clearly accelerated the kinetics of curing whilst oxidation of carbon powders could remove their catalysing effect. These results were confirmed by monitoring the changes in conversion of epoxy and amine groups during cure using the FTIR technique. DSC experiments also showed the influence of carbon powder as a catalyst and the loss of the catalysing effect as a consequence of chemical treatment. |
