Effect of Functionalize Carbon Nanotubes with Amine Functional Group on the Mechanical and Thermal Properties of Styrene Butadiene Rubber

This article reports the investigations carried out on styrene butadiene rubber (SBR) matrices filled with functionalized multi-wall carbon nanotubes (MWNTs). MWNTs were functionalized with amine functional group to enhance its dispersion in SBR nanocomposites. The functionalization of the surface of the carbon nanotubes (CNT) was carried out by using nitric acid at 120 degrees C for 48 h. The FTIR technique was used to characterize the surface of the functionalized CNTs to ascertain the presence of the functional groups on the CNT surface. The modified CNTs were incorporated into a polymer solution and this was followed by subsequent evaporation of the solvent. This technique can be employed to ensure a homogeneous dispersion of nanotubes in the SBR matrix in order to increase the mechanical and thermal properties of the resulting nanocomposites. Results obtained shows significant improvement in the mechanical as well as thermal properties of the nanocomposites. For example the tensile strength increased from 0.16 MPa (blank SBR) to 0.45 MPa (10% CNT) while the young modulus increased from 0.2 MPa (blank SBR) to 0.55 MPa when 10% functionalized CNT was added. Also optimum value of 4.1 KJ energy absorption was obtained with the incorporation of 1% CNT into the SBR matrix. Significant increase in the glass transition temperature was also observed compared to the pure SBR. Thus, CNT functionalized with amine group can be considered as excellent nanofiller for increasing the reinforcing efficiency of SBR.