Studies on the conductivity properties of a family of cyanoethylated amine cured epoxy resin matrices

摘要

A group of epoxy matrices having a varied amount of crosslink densities have been prepared by curing diglycidyl ether of bisphenol A (DGEBA)-epoxy resin with the help of a family of cyanoethylated amine hardeners based on the adducts of 1 mole of triethylenetetramine and x moles of acrylonitrile, where x = 1, 2, and 3, to effect increasing level of cyanoethylation of triethylenetetramine. The electrical conductivities of such epoxy matrices having increasing crosslink densities were evaluated by a two-probe a.c. technique in the frequency range of 100 Hz to 13 MHz using an impedance analyzer in the temperature range from 299 to 495 K. It was observed that the conductivity increased with an increased level of cyanoethyl (-CH2CH2CN) moiety in the matrix resin, while the activation energy (E-c) of conductivity in the elastomeric region above T-e generally showed a reversed trend with respect to E-v from 1.11 to 0.83 eV, where T-c is defined by T-c = (T-g + DeltaT), the (DeltaT) for this family of matrix resin being 44.83degreesC. (C) 2003 Wiley Periodicals, Inc. [References: 26]