Material Characterization of Graphite Nanosheet Composites

Three sets of expanded graphite-filled polymers, having three different particle sizes, were reinforced with 1-5% by weight. The structural, mechanical, electrical, and thermal properties of these composites were studied and compared. After dispersion, the particles were reduced to nanometer size through exfoliation, sonication, and high-shear strain rate mixing, which further breaks and delaminates them. In addition, scanning electron microscope characterizations were performed. The expanded graphite-filled polymer material could be tailored to be high conducting. Compared with the pure polymer, the polymers filled with 5 wt% expanded graphite have seen a significant reduction in electrical resistivity by orders. The thermal expansion coefficient and water absorption for the weight containing 5 wt% expanded graphite has also been drastically improved, decreasing with the weight percentage of graphite content. Compression and impact tests were conducted. The influence of dispersion on the material behavior was studied. Some fracture modes associated with the layered microstructures of the graphite nanosheets were observed. POLYM. COMPOS., 32:305-313, 2011. (C) 2010 Society of Plastics Engineers