Temperature dependent electrical conductivity of CNT-PEEK composites

The effect of temperature on electrical conductivity of nanocomposites consisting of Chemical Vapor Deposition (CVD)-grown multi-walled Carbon Nanotube (MWCNT) and Poly Ether Ether Ketone (PEEK) is presented in this paper. Different weight percentages of carbon nanotubes (CNT) were dispersed in PEEK through shear mixing by calendaring technique in Brabender. Percolation limit of the system was measured and discussed. The resulting nanocomposites were molded into round shaped pieces of 25.4 mm diameter and 1.4 mm thickness. The samples were then heated from room temperature to 140 degrees C while electrical conductivity is measured. It is found that electrical conductivity increases significantly with the increase in temperature and the rate of increase in conductivity with temperature depends on the content of CNT. The change in electrical conductivity does not follow the same route for heating and cooling cycle, thus resulting in electrical hysteresis. (C) 2011 Elsevier Ltd. All rights reserved.