The effect of carbon black concentration on microwave cure kinetics of epoxy materials - diglycidyl ether of bisphenol A (DGEBA) / diaminodiphenyl sulfone (DDS) - is studied. The dielectric properties of the uncured neat and filled resins were measured with single mode perturbation method at room temperature. Results showed that the magnitude of the dielectric properties increased drastically with increasing concentration of carbon black. Microwave curing experiments were carried out at three different temperatures with different carbon black concentrations. Parallel thermal curing was also performed for comparison. A phenomenological kinetic model was used to describe the autocatalytic behavior of the curing reaction of both neat and filled epoxy systems. The reaction rate constants and the kinetic exponents were obtained with a least-square fit of experimental data to the kinetic model equation. For the neat epoxy resin, the curing rates with microwaves were much higher than that with thermal method. In thermal curing of the resins with different carbon concentrations, the rate constants first decreased to a minimum and then increased with increasing carbon concentration. The minimum reaction rates corresponded to a carbon concentration of 1wt%. This trend was more obvious at higher temperature. In microwave curing process, the reaction rate constants decreased with increasing carbon concentration.
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