Reinforced natural rubber nanocomposites using graphene oxide as a reinforcing agent and their in situ reduction into highly conductive materials

In this study, a new method of fabricating conductive NR nanocomposites was proposed. Graphene oxide (GO) was obtained through oxidization and exfoliation of graphite and was employed as a reinforcing nanofiller for natural rubber (NR). GO/NR nanocomposites with different concentrations of GO were prepared by a latex mixing and casting method. The nanocomposites were characterized by Raman spectroscopy and TEM, and the thermal and mechanical properties were evaluated by TGA, DSC, tensile testing, and DMA. The results showed that the nanocomposite showed a segregated “weblike” morphology. The addition of GO slightly decreased the glass transition temperature of NR and improved the thermal stability of the material. The tensile strength and storage modulus of the nanocomposites significantly increased with the GO contents, indicating GO had a strong reinforcing tendency on NR. The electrically conductive reduced graphene oxide (r-GO)/NR nanocomposites were obtained by immersing GO/NR nanocomposites in a hydroiodic (HI) acid aqueous solution for reduction. HI acid can efficiently reduce the GO into graphene in 2 h at 60°C. The volumetric electrical conductivity of the nanocomposites increased with the r-GO contents, and the conductivity of the 5% r-GO/NR nanocomposite was as high as 1 S/m, which showed its promising application as stretchable electrical conductors and elastomers. POLYM. COMPOS., 38:E199–E207, 2017.