Polypropylene – Single Walled Carbon Nanotube Nanocomposites: Functionalization, Processing and Properties

The chemistry, processing, and concentration of carbon nanotubes have a tremendous impact on the thermal stability and mechanical properties of the final melt extruded polymer nanocomposite. Functionalization is generally accepted to improve dispersion by increasing steric hindrance between the carbon nanotubes and creating a compatible interface between the carbon nanotubes and polymer chains. However, functionalization also deteriorates nanotube properties and introduces impurities that can catalyze polymer degradation. We report the influence of different functional groups, extruder processing conditions, and nanotube concentration on the properties of single-walled carbon nanotubes (SWNT) - polypropylene (PP) nanocomposites. The nanotubes and PP are premixed in a rotary evaporator followed by melt extrusion. The degree of SWNT dispersion in PP was analyzed by optical microscopy and Scanning electron microscopy, and Raman mapping. In addition, rheological characterization was performed to study the variation in PP viscoelasticity due to the addition of SWNTs and the effects of processing conditions. Finally, thermal and mechanical characterization was executed to understand the relationship between the nanocomposite microstructure, and thermal and mechanical properties.