Development of an additive equation for predicting the electrical conductivity of carbon‐filled composites

Abstract

ABSTRACT:The electrical conductivity of polymeric materials can be increased by the addition of carbon fillers. The resulting composites can be used in applications such as electrostatic dissipation and interference shielding. Electrical conductivity models are often proposed to predict the conductivity behavior of these materials. The electrical conductivity of carbon-filled polymers was studied here by the addition of three single fillers to nylon 6,6 and polycarbonate in increasing concentrations. The fillers used in this project were carbon black, synthetic-graphite particles, and milled pitch-based carbon fibers. Materials were extruded and injection-molded into test specimens, and then the electrical conductivity was measured. Additional material characterization tests included optical microscopy for determining the filler aspect ratio and orientation. The filler and matrix surface energies were also determined. An updated model developed by Mamunya and others and a new additive model (including the constituent conductivities, filler volume fraction, percolation threshold, constituent surface energies, filler aspect ratio, and filler orientation) fit the electrical conductivity results well.

Electrical Conductivity Modeling of Polypropylene Composites Filled with Carbon Black and Acetylene Black

“…But at the onset of the percolation threshold the conductivity increases drastically as illustrated in Figure 2 on a semilogarithmic scale. Beyond a certain critical concentration this increase seems to be evolving more moderately [21][22][23][24].…”

Electrical, Thermal, and Morphological Properties of Poly(ethylene terephthalate)-Graphite Nanoplatelets Nanocomposites

“…Thus, Φ of these nanocomposites is expected between 5 and 9 wt.% loadings of the GNP. Typically, the variation in the conductivity of PCs as a function of the conductive filler content exhibits an S-shaped curve for transition from insolating to conductive system [16]. Therefore, the PET-GNP nanocomposites exhibited a typical transition curve ( Figure 1) in this study.…”

“…This theory will assist the determination of dimensions of conductive network in polymer matrices and percolation threshold values of PCs system. According to this theory, of the PCs is calculated by the following equation [11][12][13][14][15][16][17][18][19]:…”

“…The density of the nanofiller (such as GNP) is frequently an approximate value. Therefore, weight fractions have been used for determining the values of Φ and t in numerous published studies [12,15,16]. In this study, all determinations will be in expression of weight fractions.…”

Material property models for polyethylene-based conductive blends suitable for PEM fuel cell bipolar plates

“…The optimum exponent values found by tuning for electrical and thermal conductivity models were on the whole greater than those by Mamunya and Clingerman where the ambient processing pressures of Mamunya 15,17 as well as the unspecified holding pressure of Clingerman 14 could have produced low exponents. Therefore, the increase in processing pressure could be one contributor to greater exponent values seen in this study due to increases in filler structure complexity with increasing pressure.…”