Polyethylene/thermally reduced graphite oxide (TRG) composites were synthesized under mild conditions (1 atm ethylene and 40 degrees C) using (n-BuCp)(2)ZrCl2 activated with methylaluminoxane (MAO) as the polymerization catalyst. The composites were characterized by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), high temperature gel permeation chromatography (GPC), and light microscopy. Although the thermal properties of the aforementioned composites were relatively unchanged when compared to polyethylene, significant enhancements in the mechanical properties were observed (e.g., up to 57% increase in the tensile strength and 170% increase the Young's modulus for composites containing 5.2 wt% TRG).