Abstract
Electrically conductive acrylonitrile butadiene rubber (NBR) compounds filled with different concentrations of graphite nanoplatelets (10 nm thickness) were experimentally investigated. The percolation concentration of the investigated nanocomposites was found to be 0.5 phr. Of all the composites examined, the sample, in the region of the percolation transition, was found most sensitive to compressive strain. The electrical conductivity of this sample was changed by more than five orders upon a 60% compression and more than two orders for 6 MPa pressure. A model description of the microstructure providing extremely strong piezoresistive effects is proposed on the basis of the conductive surface network of the nanocomposite. The experimental data for compressive strain are in good agreement with theoretical equations derived from a model based on the change of particle separation under applied stress. Copyright (C) 2011 John Wiley & Sons, Ltd.