An empirical equation for electrical resistivity of thermoplastic polymer/multi-walled carbon nanotube composites

Industrial grade multi-walled carbon nanotubes (Nanocyl 7000) were incorporated into various thermoplastic polymers, such as polyamide 6, polyamide 11, polyamide 12, high-density polyethylene, polypropylene and polycarbonate, by a simple melt mixing process. An empirical equation has been fit to electrical measurements obtained by several experiments. The proposed empirical equation fit all of the experimental data above the percolation threshold concentration very well, and it has been proven that each parameter of the empirical equation has a strong correlation with the state of dispersion of the carbon nanotubes. Furthermore, for the first time, the Hansen solubility parameter has been used to predict compatibility between carbon nanotubes and thermoplastic polymers, and the predicted result strongly resembles data obtained in several other reports. (C) 2010 Elsevier Ltd. All rights reserved.