Conductive properties of flexible polymer composites with different carbon-based fillers

This paper is devoted to the comparative study of conductive properties of three types of flexible polymer composites consisting of styrene-butadiene rubber (SBR) as a matrix and graphite, graphene or single-walled carbon nanotubes as fillers. The dependences of the resistivity on the mass fraction of different fillers are measured and analyzed within the framework of the statistical percolation theory. The percolation parameters (the values of the percolation threshold and the critical exponent) are calculated for all studied composites. Their variation depending on the filler type is discussed, taking into account a geometric shape of filler particles and the nature of the conduction process in composites in the percolation range. The sensitivity of the resistivity of synthesized composites to axial deformation at different mass fraction of fillers is also investigated. Using graphite or graphene fillers is observed to result in a higher sensitivity compared to the carbon nanotubes filler. The highest value of the gauge factor is observed when using 23 mass.% graphene filler that indicates graphene/SBR composites to be most promising for creating strain sensors.