Rheokinetic and Dynamic Mechanical Analysis of Tetrafunctional Epoxy/anhydride Mixtures. Influence of Stoichiometry and Cure Conditions

Abstract

The copolymerization of hexahydrophthalic anhydride (HHPA) with N, N, N′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane (TGDDM) has been studied for several stoichiometric ratios. The rheological, thermal and dynamic mechanical behaviors of these systems were examined. Kinetic studies by differential scanning calorimetry, in both isothermal and dynamic modes, showed a first-order kinetics. Activation energies were also obtained by rheological measurements, through gelation times at different temperatures, with results in agreement with calorimetric results. The dynamic mechanical behavior was studied to analyse the influence of both stoichiometric ratio and cure schedule in the viscoelastic properties of the mixtures.