ABSTRACT: This research presents the effect of conductive network formation in the melt (dynamic percolation) to the conductivity of the composite for a multi-walled carbon nanotube/thermoplastic polyurethane composite system. An extremely low percolation threshold 0.13 wt.% was achieved in the melt processed composite film samples, whereas a much higher CNT concentration (3~4 wt.%) is needed to form a conductive network for the composite strands directly extruded from the melt. This is explained by the dynamic percolation behaviour of the CNT network in the melt. The temperature and CNT concentration needed to activate dynamic percolation in this composite was studied by measuring the conductivity temperature dependence of the extruded strand, in an attempt to give an estimation of processing conditions needed for optimized final product fabrication.
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