PROCESSING EFFECTS ON PERMANENT ELECTRICALLY CONDUCTIVE HDPE-CONDUCTIVE CARBON BLACK COMPOSITES

摘要

Still today conductive carbon black is the most widely used solution to give permanent electrical conductivity to plastic materials. The electrical conductivity of the final material is known to be affected by processing history and especially by final transformation processes, as they can induce changes in the properties or the distribution of the filler. In a recent work, we highlighted the large difference between the percolation curves of compression and injection molded samples of conductive and extra-conductive carbon black loaded HDPE. Such a difference can be addressed to various effects such as surface induced segregation, carbon black structure reduction or different crystallization of the polymeric matrix. In this work, by simple yet specific tests, we investigate the relative importance of these factors and evaluate their contributions to the modified final electrical properties of the material.