Effect of MWCNT dimension on the electrical percolation and mechanical properties of poly(vinylidenefluoride-hexafluoropropylene) based nanocomposites

Multi-walled carbon nanotube/poly(vinylidenefluoride-hexafluoropropylene) (MWCNTs/PVDF-HFP) nanocomposites were prepared by a simple fabrication method. The influence of MWCNT dimension on the mechanical properties and the electrical conductivity of the as-prepared nanocomposites were evaluated. The results show that the incorporations of MWCNTs improve the tensile strength and modulus of the PVDF-HFP. The nanocomposites filled with longer MWCNTs exhibit higher tensile strength and Young's modulus than the ones filled with the shorter ones, which derives from the more even distribution of the longer MWCNTs in the matrix. The test results of the electrical conductivity show that the nanocomposite has electrical percolation behavior. The percolation threshold is significantly affected by the length and the dispersion level of the MWCNTs. The nanocomposite reinforced with the longest MWCNTs has the lowest percolation threshold of 0.145 wt% due to the most even dispersion of the longest MWCNTs in the composite. (C) 2014 Elsevier B.V. All rights reserved.