Electrical, mechanical and thermal properties of graphene nanoplatelets reinforced UHMWPE nanocomposites

Highlights: • GNP/UHMWPE nanocomposites were prepared by solution mixing followed by compression molding. • The electrical conductivity of GNP/UHMWPE nanocomposites shows percolation threshold at 3.0 wt% of GNP. • The elastic modulus and yield strength increase by 30% and 21%, for the addition of 0.5 wt% and 1.0 wt% of GNP, respectively. • With the addition of 0.1 wt% CNT, lower percolation threshold was achieved for CNT_0.1/GNP_x/UHMWPE hybrid nanocomposites. -- Abstract: Here, we report the electrical, mechanical and thermal properties of ultrahigh-molecular-weight polyethylene (UHMWPE) nanocomposites reinforced with 0.1 wt% to 10 wt% of graphene nanoplatelets (GNP). The electrical conductivity of GNP/UHMWPE nanocomposites shows percolation threshold at 3.0 wt% of GNP. A significant increase in electrical conductivity from 10⁻¹⁵ S cm⁻¹ for neat UHMWPE to 10⁻⁵ S cm⁻¹ at 3.0 wt% GNP loading of GNP/UHMWPE nanocomposite (i.e. 10 orders of magnitude higher) is due to the formation of an almost three-dimensional conductive network. The highest value of electrical conductivity (1.09 S cm⁻¹) is observed at 10.0 wt% of GNP loading. The elastic modulus and yield strength increase by 30% and 21%, for the addition of 0.5 wt% and 1.0 wt% of GNP, respectively, while fracture toughness and the ultimate tensile strength decrease significantly above 0.5 wt% GNP loading. This study demonstrates the fabrication of GNP/UHMWPE bio-nanocomposites, which exhibit electrical properties useful for smart biomedical implants.