Enhanced dispersion for electrical percolation behavior of multi-walled carbon nanotubes in polymer nanocomposites using simple powder mixing and in situ polymerization with surface treatment of the fillers

The electrical conductivity of nanocomposites with a Cyclic Butylene Terephthalate (CBT) matrix and multi-walled carbon nanotubes (MWCNTs) was investigated. Uniform dispersion of the incorporated MWCNTs in the nanocomposites was achieved using a novel preparation method that involved powder mixing and in situ polymerization. Promoted and retarded results at the percolation threshold were observed, and the trend strongly depended on the surface treatment of the MWCNTs, such as acid, hydrogen peroxide and heat treatments. The electrical percolation behavior of nanocomposites with surface treated MWCNTs has been a controversial topic in the literature. The defect and resistivity of MWCNTs, which were expected to be important physical factors that influence the electrical conductivity of the nanocomposites, were found to have only a minor influence. Different functionalities of the MWCNTs after surface treatments altered the dispersion state of the incorporated MWCNTs in the nanocomposites, and the dispersion state was the dominant physical factor that governed the electrical percolation behavior of the nanocomposites. (C) 2013 Elsevier Ltd. All rights reserved.