Electrical Properties of Carbon Black-Polyethylene Composites

Abstract

The relationship between current density and applied DC electric field was measured for carbon black-polyethylene composite films which contain large amounts of carbon black by volume fraction (vr =c 0.16-0.28). The curves relating the current density to the applied DC electric field for the samples show clearly that, at first, the current densities increase in proportion to the applied DC electric fields and then, after the greatest values, they decrease and show negative resistance at high applied DC electric fields. The shapes of the curves are very sensitive to the volume fraction of the carbon black, to a previously applied DC voltage during the sample film molding, and to the density of the matrix polyethylene; yet there is almost no influence due to the particle size of the carbon black or to the melt index of the matrix polyethylene. This finding can be explained well by the tunneling of carriers across the barriers and the generation of Coulomb forces among the carbon black particles.

Prediction of the DC electrical conductivity of carbon black filled polymer composites

“…This jump in DC conductivity can be attributed to the formation of an infinite agglomerate pathway, which allows electrons to travel a macroscopic distance through the polymer composite. This general behavior has been observed in a significant number of conducting polymer composite systems [2,[22][23][24][25][26]. All the concentrations in series B and C are higher than the threshold / c .…”

A novel way of enhancing the electrical and thermal stability of conductive epoxy resin–carbon black composites via the Joule heating effect for heating‐element applications

“…The I-V curves in Figures 12 and 13 are described by the following empirical formula: 11 I ϭ V aV 3 ϩ bc (18…”

“…8 However, one of the key problems related to the potential application of conductive polymers is stability and reproducibility (i.e., reliability). The most promising approaches to the solution of this problem are a long annealing time, 9 the reprocessing of green polymer, 10 the addition of inhibitor additives, 10 the modification of the molecular structure, 11 irradiation, and others. [1][2][3] From a technological point of view, all of these methods are inconvenient, expensive, and time consuming.…”

Novel gas sensor from polymer-grafted carbon black: Vapor response of electric resistance of conducting composites prepared from poly(ethylene-block-ethylene oxide)-grafted carbon black

“…From the experimental result, therefore, we consider that CB was dispersed in the composite nonuniformly even if the composite was prepared from polymer-grafted CB. 1,6,40 As another possible mechanism, the electric resistance of the composite electrode drastically increases in the solvent vapor due to the swelling of the matrix polymer, which was caused by the absorption of the solvent vapor. But we hardly observed the abrupt resistance change of the composite from amorphous PEI-grafted CB in the vapor of a good solvent of PEI.…”