Effect of small additions of carbon nanotubes on the electrical conductivity of polyurethane elastomer

The effect of small (0.002–0.018 wt %) additions of single-walled carbon nanotubes on the dielectric properties and electrical conductivity of crosslinked polyurethane elastomer is studied in the temperature range of 133–453 K and the 10^?3 to 10⁵ Hz range of electric field frequencies. It is shown that the dependence of direct current conductivity σ _dc on temperature deviates significantly from the Arrhenius dependence and is described by the Vogel-Fulcher-Tamman equation σ _dc = σ _dc0exp{?DT ₀/(T ? T ₀)}, where T ₀ is the Vogel temperature and D is the strength parameter. A correlation is found between the nonmonotonic dependences of the glass transition temperature (T _g), D parameter, and σ _dc and the concentration of nanotubes with earlier results for their effects on the physicomechanical characteristics (strength and Young’s modulus) of these systems.