ISOTHERMAL AND DYNAMIC REACTION-KINETICS OF HIGH-PERFORMANCE EPOXY MATRICES

The reaction kinetics of the epoxy matrix of a commercial prepreg for high performance composites, based on tetraglycidyl diamino diphenyl methane-diamino diphenyl sulfone (TGDDM-DDS) formulation, has been characterized by differential scanning calorimetry (DSC). A phenomenological kinetic model, able to describe the behavior of the system during normal processing operations has been formulated. The diffusion control phenomena, related to the evolution of the glass transition temperature as a function of the degree of polymerization, has been considered in the formulation of the kinetic model. Isothermal and dynamic tests have been used to calculate the model parameters and to verify the proposed model. The model is able to describe incomplete reactions in isothermal tests and heating rate dependence of dynamic test thermograms, and it has been also successfully applied to DSC experiments performed with complex thermal conditions commonly used in the processing of high performance composites.