THE APPLICATION OF A NEW CONFIGURATIONAL ENTROPY MODEL TO THE STRUCTURAL RELAXATION IN AN EPOXY-RESIN

The aim of this work is to model the structural relaxation of a fully cured epoxy resin. The samples were subjected to thermal treatments in volving isothermal annealing at temperatures T-a for times t(a) before the measuring scan carried out on heating in the DSC. The values of T -a ranged between T-g-8 and T-g-50 degrees C and those of t(a) between 0 and 16000 min. A new model based on the evolution of the configurat ional entropy was used to simulate the experimental data, obtained pre viously by one of the authors. A curve of calorimetric relaxation time s as a function of reciprocal temperature and the beta parameter of th e KWW equation were determined from a comparison between experimental and calculated thermograms. Using the peak shift method, the Narayanas wamy parameter x was determined from both the experimental and simulat ed scans. The calorimetric relaxation times are compared with those fo und for dielectric and dynamic-mechanical relaxation. (C) 1998 Elsevie r Science Ltd. All rights reserved.