Unique Rheological Response of Ultrahigh Molecular Weight Polyethylenes in the Presence of Reduced Graphene Oxide

Abstract

The paper addresses the difference in electrical conductivities and rheological properties between two nanocomposites of reduced graphene oxide nanosheets (rGON) with commercial ultrahigh molecular weight polyethylene (C_PE) and a low-entanglement-density UHMWPE synthesized under controlled conditions (Dis_PE). It has been found that composites made with Dis_PE can reach conductivities at least 100 times higher than those made with C_PE on doing thermal treatment at lower temperatures. However, the difference in the electrical conductivity diminishes when both sets of samples are given a high temperature treatment. This phenomenon is attributed to the difference in morphology of the polymer matrices, for example, grain boundaries between the nascent particles. Furthermore, rheological analyses of the two sets of UHMWPE/rGON nanocomposites conclusively demonstrate differences in the interaction between polyethylene chain segments of the disentangled UHMWPE and rGON, compared to the entangled commercial UHM...