Processing and properties of polyethylene reinforced by graphene nanosheets and carbon nanotubes

High density polyethylene (HDPE)/graphene nanosheets (GNs) and HDPE/Multi-Walled Carbon Nanotubes (MWCNTs) nanocomposites with 0.5%, 1% and 3% nanofiller contents were prepared using the melt mixing method. The dispersion of the nanofillers in the polymer was monitored by scanning electron microscopy and melt rheology studies. Morphological, rheological, thermal and tensile properties of nanocomposites were comparatively studied. The results were discussed in terms of the geometries of GNs and MWCNTs. It was found that the HDPE/GNs nanocomposites show better properties than HDPE/MWCNTs nanocomposites at identical filler content. The superiority of HDPE/GNs nanocomposites may be due to high specific surface area and nanoscale 2-D flat surface of GNs which result in an enhanced mechanical interlocking with the polymer chains and enlarged interphase zone at filler–polymer interface. This effect is less pronounced in MWCNTs based nanocomposites because the MWCNTs have a reduced surface area and can interact with the polymer only at 1-D linear contact.