Conductive polymer composites

The modification of electrical and mechanical properties of a low-density polyethylene (LDPE) filled with copper particles, having an average diameter of 40 mu m, has been analyzed. A drastic decrease of the electrical resistivity of the composites is observed, about 14 orders of magnitude when 40 volume percent of copper is added. The mechanical properties of the composites are poor. Accelerated thermal tests were carried out and they did not reveal significant polymer thermal degradation in the presence of the copper particles. Melt mixing is by far superior to dry blending for sample preparation due to a much better homogenization of particles within the polymer matrix. An on-going work focuses on improvement of the mechanical properties by using coupling agents.