Effective strategy for improving electrical properties of polyethylene insulating materials by doping graphene

Graphene (GR) has attracted wide attention as a filler for nanocomposites due to unique electrical properties, high specific surface area and mechanical strength. However, it is difficult to disperse uniformly in matrix because of its high surface energy. In this work, the nanocomposites with high DC breakdown strength are successfully prepared by blending newly synthesized voltage stabilizer noncovalent functionalized GR into linear low density polyethylene/linear low density polyethylene-graft-polystyrene (LLDPE/PES). The results show that the electrical insulation properties of nanocomposites are improved significantly due to the introduction of a great number of deep traps by GR. The internal space charge is suppressed obviously and DC breakdown strength of the nanocomposite prepared by introducing 3.0 wt% voltage stabilizer and 0.005 wt% GR reaches 400.1 kV mm −1 , which is 41.6% higher than that of pure LLDPE. This study provides a new strategy for the development of polyethylene insulating materials by introducing noncovalent functionalized GR. Graphical abstract