Electrical and mechanical properties of -hydroxynaphthoic acid-multiwalled carbon nanotubes-polystyrene nanocomposites

The effect of -hydroxynaphthoic acid (-HNA) addition on electrical and mechanical properties of multiwalled carbon nanotubes (MWCNTs)-polystyrene (PS) composite at a fixed amount of MWCNTs (0.85 wt%) are delineated. Obtained electrical, mechanical, morphological, and Fourier transform infrared results showed that addition of -HNA up to 1 wt% to MWCNTs-PS composite enhanced the dispersion of MWCNTs in the neat PS, formation of MWCNTs-PS network, relative permittivity, dielectric loss, and the electrical conductivity increased by about three orders of magnitude for the prepared composite. Dielectric relaxation results showed that at the domain frequency range, the relaxation process below 1.0 wt% -HNA was mostly due to polymer molecular relaxation process, while at 1.0 wt% -HNA, the composite relaxation behavior was mostly due to charge conductivity relaxation. Mechanical results showed that addition of -HNA to composite system up to 1.0 wt% increased the elastic modulus, yield stress, and tensile strength of the composites by about 12.2, 17.1, and 10.0%, respectively, which indicated that the addition of -HNA to composite system improved MWCNTs dispersion in PS matrix and enhanced the interfacial bond in the -HNA-MWCNTs-PS network.