Stability of electrical and mechanical properties of polyethylene/carbon black composites

The stability of electrical and mechanical properties of two kinds of polymer composites ‐ polyethylene/carbon black and polyethylene/carbon black modified by polypyrrole ‐ was investigated during slow cycle heating and cooling. Conductivity in composites was measured in heating/cooling cycles in the temperature range from 16°C to 125°C. It was found that the thermal treatment resulted in the conductivity changes and the mechanical properties of treated composites have also been influenced. The effect was explained by increased crystallinity in the polymer matrix of thermally treated composites.