Electrical behavior of polypropylene/multiwalled carbon nanotube nanocomposites with low percolation threshold

Polypropylene (PP)/multiwalled carbon nanotube (MWNT) nanocomposites were prepared via melt-compounding. The dielectric and conductive properties of the nanocomposites were examined. It was found that better dispersion of MWNTs in PP matrix can be achieved in a Haake mixer by intensive shearing. Accordingly, PP/MWNT nanocomposites prepared at high shear rates exhibited much lower percolation thresholds than composites fabricated at low shear rates. The resistivity results revealed that the PP/MWNT nanocomposites with a high MWNT content exhibited a positive temperature coefficient effect. (c) 2007 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.