Effect of the morphology of thermally reduced graphite oxide on the mechanical and electrical properties of natural rubber nanocomposites

Graphene materials often are obtained through thermal reduction of graphite oxide. This is due to the fact that other synthesis methods are more difficult and generally render lower yield. The structure and morphology of these graphene materials could affect their performance in different applications. Herein, thermally reduced graphite oxide (TRGO) was obtained from thermal reduction of graphite oxide prepared by using the methods reported by Brodie and Hummers. The oxidation method greatly affects the structure and morphology of the resulting TRGO. TRGO obtained by the Brodie's method generates a morphology comprised of rather exfoliated galleries while that obtained by the Hummers method presents randomly distributed sheets. The influence of structural differences on the dispersion of TRGOs in natural rubber latex (NR) and on the resulting mechanical and electrical properties of the TRGO/NR nanocomposites is studied. The TRGO prepared by the Brodie's method (TRGO-B) showed a more homogeneous dispersion in the polymer–matrix, rendering enhanced mechanical and electrical properties of their nanocomposites. TRGO-B/NR nanocomposites showed higher electrical conductivity, which is attributed to the formation of an electrically conducting filler network through the polymer–matrix. This is consequence of the morphology presented by TRGO produced by the Brodie's method.