Temperature dependence of electrical properties of epoxy-glass microballoons composite

This study concerns with temperature dependence of some electrical properties of epoxy-glass microballoons composite containing 0, 15, 35, and 55% by weight glass microballoons. Impedance measurements were done in temperature range of 20-125 degrees C at applied frequencies 100 Hz and 10 kHz. It was found that impedance decreases and a.c.-conductivity increases at temperatures above 80 degrees C. The calculated dielectric constants showed a rather strange dependence on temperature. The obtained spectrum of relaxation times determined from impedance plots imply that different conduction mechanisms are possible to take place at different filler concentrations.