Research at Michigan State University has shown that it is possible to exfoliate natural graphite into stacks of graphene nanoplatelets having thicknesses of less than 10nm and diameters of any size from sub-micron to 15 microns or greater. Since graphene is one of the stiffest materials found in nature (Young's Modulus = 1060 GPa), and also has excellent electrical and thermal conductivity, the addition of graphene nanoplatelets to polymers should have a beneficial effect on the resulting composite physical properties. In order to get good dispersion of graphene nanoplatelets (GnP) in the matrix and good adhesion between the GnP and the matrix, functionalization of the GnP is one of the most effective approaches. We have investigated functionalization of GnP with DGEBA and maleic anhydride, which was then used to fabricate GnP/vinyl ester nanocomposites. The thermal, mechanical and electrical properties of these nanocomposites have been evaluated. Morphology results showed that functionalization improved the dispersion of GnP in the matrix. Dispersion of GnP is an important factor to control mechanical properties of its reinforced nanocomposite. DGEBA-MA functionalized GnP reduced the electrical conductivity of it reinforced nanocomposite, however, DGEBA-MA significantly improved the flexural strength and unnotched Izod impact strength. In addition, DGEBA-MA functionalized GnP also reduced the thermal conductivity.
