Influence of three-hydroxy-2-naphthoic acid functionalized SWCNTs on the electrical and mechanical properties of poly (vinyl chloride)

Two main groups of samples were prepared. The first one was poly (vinyl chloride) (PVC) loaded with different concentrations of as received single walled carbon nanotubes (SWCNTs), while the second was PVC loaded with different concentrations of single walled carbon nanotubes functionalized with three-hydroxy-2-naphthoic acid (-HNA) at a concentration of 0.04wt%. The dc electrical conductivity and its temperature dependence of theses samples were investigated. Also, the tensile, rheological as well as the dynamical mechanical properties of all samples were studied. Functionalization of SWCNTs with -HNA was found to enhance the dc electrical conductivity, elastic modulus, tensile strength, complex viscosity, storage modulus and the glass transition temperature. The dc electrical conductivity had a percolation behavior with a percolation threshold concentration of 0.35 and 0.22wt% of un-functionalized and functionalized CNTs, respectively. The enhancement of the electrical and mechanical parameters with functionalized SWCNTs indicated well dispersion of CNTs due to formation of side functional groups on their sides.