A nylon 6/graphite composite was synthesized using P-caprolactam monomer polymerization blended with graphite oxide (GO). Absorptions at 3300 cm(-1) due to the N-H group, at 2900 cm(-1) due to the C-H, at 1640 cm(-1) due to the C=O, and at 1545 cm(-1), due to stretching vibration of the C-N because of an amide group were observed in the infrared (IR) spectrum. This agrees with the IR absorption of nylon 6, suggesting the successful synthesis of a nylon 6/graphite composite. Moreover, the diffraction peaks of GO shifted from 26.6 degrees to 10-15 degrees in X-ray diffraction (XRD), suggesting the successful oxidation of NG and effective enlargement of the space between each of the graphite layers. After thermal reduction of GO, the electrical conductivities of the composites were examined. The results showed that as the concentration of GO increased from 0.25 to 3 wt%, the electrical conductivity increased from 2.5 x 10(-14) to 6.5 x 10(-3) S cm(-1). In addition, the effects of composite molecular weight, such as reaction atmosphere, catalyst, reaction time, and reaction temperature were also investigated in detail. (C) 2009 Elsevier B.V. All rights reserved.