The electrical conductivity of ethylene butyl-acrylate/carbon black composites: The effect of foaming on the percolation threshold

The main objective of this work is to study the influence of foaming on the percolation threshold of carbon black-filled polymer composites. The electrical conductivity, structure and tensile strength properties of solid and foamed ethylene butyl-acrylate/carbon black composites were investigated. The percolation threshold of solid composites was 10.9 vol.%, whereas for composite foams it decreased to 5.8 vol.% of carbon black. It was found that the charge transport mechanism of composites was not affected by the foaming. The reported decrease of the percolation threshold is attributed rather to the volume exclusion effect and carbon black redistribution. As a result, a conducting composite with a reduced specific volume and filler content can be prepared. (C) 2013 Elsevier B.V. All rights reserved.