Effect of reduced graphene oxide, multi-walled carbon nanotubes and their mixtures on the electrical conductivity and mechanical properties of a polymer composite with a segregated structure

The development of new electrically conductive polymer composites is one of the most important research areas of composite materials science community nowadays. This work is devoted to the preparation and study of electrically conductive polymer composites with a segregated network structure with mixtures of reduced graphene oxide/multi-walled carbon nanotubes (rGO/MWCNTs) in various ratios. At a fixed value of the total mass fraction of rGO/MWCNTs (1 wt.%), the set of samples with different rGO/MWCNTs ratio was obtained and examined via scanning electron microscopy, wide range dielectric spectroscopy and tested under compression. We have shown that the use of graphene oxide in a mixture with MWCNTs makes it possible to significantly improve the uniformity of MWCNTs distribution during the formation of a filler layer on polymer particles, which leads to an increase in the electrical conductivity of the composites in comparison with samples containing only rGO or MWCNTs. It was also shown adding 1 wt.% of rGO to the polymer increases the elastic modulus by 18% compared to the pure polymer. In turn, adding of MWCNTs, there is a drop in the elastic modulus by a quarter. It was found that fillers do not affect the plastic flow initiation stress of the material, which is 21 ± 1 MPa. Graphical Abstract