Electrical and Mechanical Properties of Some Composites with Polymeric Matrix

Abstract The present study aims to investigate the dielectric properties as well as the mechanical properties of polymethyl methacrylate-carbon black and polyester-carbon black composites using semi-reinforcing furnace (SRF) and high abrasion furnace (HAF) carbon blacks. The permittivity e' was found to increase by increasing carbon black content and showed anomalous dispersion. The absorption spectra (e'' vs. frequency) from 100 Hz to 10 MHz were analyzed using a computer program based on Frohlich terms. Four absorption regions were obtained for either the polymer matrix or loaded samples. The first region in the lower frequency range could be attributed to Maxwell-Wagner effect resulting from the differences in the conductivities of the ingredients of the composite. The second and third regions in the higher frequency range could be attributed to the large and small aggregates caused by movements of the main chain. The fourth region may occur due to segmental rotation (ester group or carbonyl group) or ...