SIMULTANEOUS KINETIC AND MICRODIELECTRIC STUDIES OF SOME EPOXY-AMINE SYSTEMS

Three reactive epoxy-amine systems based on diglycidyl ether of bisphe nol A (DGEBA) with 4,4'-diaminodiphenylsulfone (DDS), 4,4'-methylenebi s [3-chloro 2,6-diethylaniline] (MCDEA), and 4,4'-methylenebis [2,6-di ethylaniline] (MDEA), were studied during isothermal curings at 140 an d 160 degrees C. The simultaneous kinetic and dielectric studies allow to express conductivity, sigma in terms of conversion, x, and of glas s transition temperature, T-g. The conductivity, sigma(0), of the init ial monomer mixture and, sigma(infinity) of the fully cured network ar e measured. It is found that: The glass transition temperature, T-g, v ersus conversion, x, curves follows the equation of Di Benedetto modif ied by Pascault and Williams There exists a linear relation between lo g sigma/log sigma(0) and T-g. So, it is possible to predict both kinet ic and dielectric behaviors of these epoxy-amine systems by the knowle dge of T-g0, Delta C-p0, and sigma(0), respectively, glass transition temperature, heat capacity, and conductivity of initial monomer mixtur e, T-g infinity and Delta C-p infinity, and a,, respectively, glass tr ansition temperature and heat capacity and conductivity of fully cured network. (C) 1998 John Wiley & Sons, Inc.