Segregated ultrahigh molecular weight polyethylene composites filled with graphene sheets and hybrid multi-walled carbon nanotubes

For the sake of comparing the different electricity conductivities of composite materials when the UHMWPE filled singleness and mixed, graphene nanosheets (GNS)-multi-walled carbon nanotubes(MWCNTs)/ultrahigh molecular weight polyethylene (UHMWPE) composites with a segregated network structure were prepared by alcohol-assisted dispersion, ultrasound and hydrazine. SEM and TEM results show that MWCNTs or GNS homogeneously disperse around UHMWPE particle, and from a segregated conductive network during the hot-pressing. It is found that the percolation threshold of GNS/UHMWPE composites (0.059%, volume fraction) is much lower than that of MWCNTs/UHMWPE composites (0.148%, volume fraction). At the same filler content, the electrical conductivity of GNS/UHMWPE composites is much lower than that of the MWCNTs/UHMWPE composites (2.0?10^-2 S/m, 1.0%, mass fraction). The percolation threshold of GNS-MWCNTs/UHMWPE hybrid composites (0.039%, volume fraction) is lower than that of composites filled with GNS and MWCNTs alone, while the conductivity of GNS-MWCNTs/UHMWPE hybrid composites (1.0?10^-2 S/m, 1.0%, mass fraction) is similar to the MWCNTs/UHMWPE composites. The mechanical properties of composites increase and then decrease with the increasing content of fillers.