Electrical properties study of carbon fillers in polymer nanocomposites
University of New Brunswick
The aim of this dissertation is to study the effect of various carbonaceous fillers on the electrical, mechanical and thermal properties within polymer composites. Three types of carbon fillers are selected; multi-walled carbon nanotube (MWCNT), carbon nanofibers (CNF) and carbon black (CB). Two types of polymers, nylon (thermoplastic) and poly-dimethylsiloxane (elastomer) are chosen as polymer matrix materials. In the processing of carbon-based polymer composites, a melt mixing method via extrusion is used to produced thermoplastic polymer composites; whereas, a solution mixing method via sonication is used to fabricate elastomeric polymer composites. With these two composite systems, the influence of filler type and loading on several composite properties is studied. The characterization consists of evaluating four attributes: dispersion, electrical resistivity, mechanical properties and thermal stability. Finally, theoretical modeling is used to study electrical properties of these composites parallel to the experimental observation. A statistical percolation theory (power law model) is applied in terms of fillers concentrations to determine percolation threshold and compare with experimental data.