Mechanical and electrical properties of poly(vinyl chloride) loaded with carbon nanotubes and carbon nanopowder

Two groups of polymer nanocomposite samples were synthesized. One of them was Poly(vinyl chloride) (PVC) loaded with different concentrations of carbon nanopowder (CNP), while the other was PVC loaded with different concentrations of carbon nanotubes (CNTs). The dependence of the tensile mechanical parameters, rheological properties and the dc electrical conductivity on the concentration of either filler was investigated. Results revealed a lower electrical and mechanical percolation threshold of CNTs than CNP. Concentration of CNTs of 1 wt% increases the elastic modulus 2.3 times greater than CNP at a concentration of 2 wt%. The storage modulus and the complex viscosity studied at a frequency of 0.1 Hz had the same behavior as the elastic modulus. The glass transition temperature was slightly changed with the addition of either nanofiller. The behavior of the temperature dependence of the electrical conductivity was found to be temperature independent in the studied range for composites containing CNTs, while composites containing CNP showed an activated one at relatively high temperatures. At concentrations in the percolation region of either CNP or CNTs, a jump region in the I-V characteristics was observed with a highest slope of 36.35 at 1 wt% of CNTs. Otherwise the conduction mechanism of the charge carriers was determined and found to be Ohmic.