Electrical Transport Study on Low-Density Polyethelene/Carbon Black Composites at Low Temperatures

摘要

Carbon black/polymer composites have shown very pronounced interests in the last years due to their wide variety of applications. Many of these applications depend on enhancing the electrical conductivity of the polymer by mixing some ratios from the carbon black as filler to the polymer matrix. This paper reports on the DC electrical conductivity of low-density Polyethelene/Carbon black composites of various CB filler concentrations at low temperatures. The composites exhibit a negative temperature coefficient of resistivity (TCR) and an increase in the electrical conductivity with decreasing temperature down to 25 K. A pronounced enhancement in the electrical conductivity with increasing the CB concentration has been observed. This enhancement in the conductivity is interpreted through the percolation theory. The observed features of the electrical conductivity for LDPE/CB composites are analyzed according to the Mott hopping mechanism.