Electrical and electromagnetic interference shielding characteristics of GNP/UHMWPE composites

Conductive polymer composites (CPC) are attractive materials for a wide range of applications because of their weight, corrosion resistivity, design flexibility and low cost. In the present work, the electrical and electromagnetic interference (EMI) shielding characteristics of graphene nanoplatelets (GNP)/ultrahigh molecular weight polyethylene (UHMWPE) composites filled with up to 40 wt% GNP were investigated. In addition, the intrinsic conductivity of the GNP network was estimated based on the statistical power law and the rule of mixtures for randomly oriented filler particles in insulating matrix. Due to the formation of a segregated conductive network at the external surface of UHMWPE powder, an electrical percolation threshold of between 2 and 3 wt% GNP was obtained. At GNP loading of 15 wt%, the composite exhibited an EMI shielding effectiveness of 33 dB, corresponding to 99.95% blocking of the EMI.