Effect of processing conditions on the dispersion, electrical, and mechanical properties of carbon nanotube/polypropylene nanocomposites

Abstract

Carbon nanotube (CNT)/polypropylene nanocomposites with different levels of CNT dispersion were created by melt mixing in order to reveal the influence of nanofiller state of dispersion on the nanocomposites electrical and mechanical properties. Optical microscopy and transmission electron microscopy were used to analyze the microstructure of the nanocomposite. Melt mixing energy, melt viscosity, and shear stress were analyzed to understand the influence of processing conditions on the microstructure and electrical properties. CNT dispersion in the polypropylene matrix was enhanced by increasing the melt mixing time and/or rotation speed. The electrical conductivity was found to be very sensitive to the changes in the CNT level of dispersion, while the tensile strength and secant modulus did not show any significant response to the enhancement in the nanofiller state of dispersion.