No abstract

This work describes the effect of reduced graphene oxide (RGO) addition in natural rubber (NR). Firstly, RGO was synthesized based on the improved Hummer’s method then characterized by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA) to confirm that the RGO surface contains hydroxyl, epoxy, and carboxyl functional groups to improve graphene interaction with the NR matrix. In a second step, the synthesized RGO was predispersed in NR latex using the co-coagulation technique then added at different amounts (0 to 2 parts per hundred rubber (phr)) to a basic NR formulation and compounded in an internal mixer. The results show that the crosslink density of the developed NR/RGO nanocomposites increased by 65% for RGO concentration of 2.0 phr. For the same RGO concentration, a significant increase in tensile strength (53%) and Young’s modulus (31%) were also observed. Finally, a significant improvement (26%) of the thermal conductivity was obtained with the addition of only 0.5 phr of RGO.

In this study, we focused on the synergistic effect between carbon black (CB) and multiwall carbon nanotube (MWCNT) hybrid fillers. In particular, the surface modification of pristine MWCNT (P-MWCNT) via an acid (oxidation) treatment was used to improve their dispersion, as well as the mechanical and thermal properties of their corresponding natural rubber (NR)-based nanocomposites. Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) were carried out to determine the presence of functional groups on the oxidized MWCNT (O-MWCNT). After vulcanization, dynamic mechanical analysis (DMA), tensile properties, hardness, thermal conductivity, swelling behaviour in toluene and SEM characterizations were performed on both NR/CB/P-MWCNT-and NR/CB/O-MWCNT-based nanocomposites. The results showed the positive effect of MWCNT surface oxidation on the fillers' dispersion and nanocomposites' properties.

Developing thermally conductive rubber nanocomposites for heat management is a difficult task for many applications, including tires. Even though rubber materials generally have poor thermal conductivity, the addition of various conductive fillers is required to prevent heat accumulation. However, high filler loading has a significant effect on the mechanical properties of the final product. In addition to the role of filler loading, structure, and morphology, various types of functionalization are required to improve the incorporation of the fillers in the rubber matrix. The main objective of this review is to summarise recent investigations on the thermal and mechanical properties of rubber nanocomposites filled with carbon-based particles such as carbon black, carbon nanotubes, and graphene derivatives.