Electrical and thermomechanical properties of segregated nanocomposites based on PVC and multiwalled carbon nanotubes

The electrical properties (dielectric characteristics and conductivity) measured on DC and AC and thermomechanical properties of polyvinylchloride-multiwalled carbon nanotube (PVC/MWNT) nanocomposites were investigated. The segregated PVC/MWCNT composites were formed by the hot compacting method. Measurement of DC and AC conductivity shows a presence of ultralow percolation threshold with value of phi(c) = 0.045 vol.%. Temperature dependence of conductivity demonstrates a transition from the ionic conductivity in pure PVC and in filled PVC below percolation threshold to the electron type of the charge transport along the MWNT phase in the composites above percolation threshold. Frequency dependence of the dielectric parameters epsilon', epsilon '' demonstrates percolation behavior of the studied systems. The thermomechanical analysis indicates the formation of a rigid network of filler in the volume of the polymer matrix, which restricts the transition of polymer into the plastic state. (C) 2009 Elsevier B.V. All rights reserved.