Exfoliation of expanded GO represents an attractive route to functionalized graphenes as versatile 2D carbon nanomaterials and components of a wide variety of polymer nanocomposites. Thermally reduced graphite oxides (TrGO) with specific surface areas of 600 to 950 m(2) . g(-1) were obtained by oxidation of graphite followed by thermal expansion at 600 degrees C. Thermal post treatment at 700 degrees C and 1000 degrees C increased carbon content (81 to 97 wt.-%) and lowered resistivity (1600 to 50 Omega . cm). During melt extrusion with PC, iPP, SAN and PA6, exfoliation afforded uniformly dispersed graphenes with aspect ratio > 200. In comparison to conventional 0D and 1D carbon nanoparticles, TrGO afforded nanocomposites with improved stiffness and lower percolation threshold. Recent progress and new strategies in development of functionalized graphenes and graphene-based nanocomposites are highlighted.