Electrical properties of segreated ultrahigh molecular weight polyethylene/multiwalled carbon nanotube composites

Multiwalled carbon nanotubes (MWNTs) and ultrahigh molecular weight polyethylene (UHMWPE) composites are prepared using paraffin as solvent. The resulting electrical properties show lower electrical percolation threshold, which is 1.4 vol %, than that of UHMWPE-MWNT composites prepared by gelation/crystallization from decalin solution. Good reproducibility and higher maximum of electrical conductivity are obtained. The extremely low electrical percolation threshold indicates that the dispersion of MWNTs is segregated, which can be proved by the morphology of the film observed by optical microscopy. The complex planes of electric modulus are useful to analyze the dispersion of MWNTs and the quality of interparticle contacts. In addition, the result of thermogravimetry shows that the retardation of onset of UHMWPE decomposition in inert gas is observed in the mixture with MWNTs. (C) 2007 Wiley Periodicals, Inc.