ANALYSIS OF THE CURE-DEPENDENT DIELECTRIC-RELAXATION BEHAVIOR OF AN EPOXY-RESIN

The dielectric relaxation behavior of an epoxy-amine resin was investigated using the Williams-Watts relaxation function. Phenomenologically, the dielectric features of the resin during cure are similar to those of stable materials. The distribution parameter of the dipole relaxation decreases from the onset of cure to a conversion near the gel point and then maintains a constant value. Based on the experimental observations and theoretical considerations, a single-frequency approach has been proposed for extracting the relaxation time of maximum loss. The relaxation data so obtained are independent of the measurement frequency and are in agreement with those acquired directly from the dipole loss peaks. (c) 1994 John Wiley & Sons, Inc.