Performance evaluation of graphite oxide in natural rubber compounds

Abstract

The performance of graphite oxides from waste batteries and carbonized maize cobs as filler in natural rubber was evaluated in this study. Graphite from carbon electrodes in waste batteries and carbonized maize cobs respectively were subjected to the conventional Hummers method for conversion to the more reactive graphite oxides. The oxides were characterized in terms of their surface area, ash content, pH, moisture content, conductivity and loss on ignition using standard methods. The oxides were further characterized in terms of their morphology and functional groups. The graphite oxides and N330 carbon black which acts as the control were then used as filler in natural rubber compounding using the two–roll mill and subjected to physicomechanical characterization. The graphite oxides showed significant enhancement in the reinforcement and mechanical properties of the natural rubber compounds as evidenced from the results obtained when compared with the control. Morphological study of the vulcanizates shows that natural rubber – maize cob graphite oxide (NR/MCGO) vulcanizates showed very good dispersion in the rubber matrix. Mechanical properties study shows that NR/MCGO vulcanizates are having improved properties with tensile strength of 32.79MPa, modulus at 100% elongation of 19.51MPa. However, NR/MCGO vulcanizates show lower elongation at break of 500.02%. The highest hardness value is NR/MCGO of 71.01 IRHD.

Keywords: Maize cob, natural rubber, fillers, graphite oxides