Nanocomposites: Manufacturing, Microstructural Characterization and Mechanical Testing

摘要

Carbon Nanotubes (CNT) offer exceptional thermal, electrical and mechanicalproperties. While an increase in thermal and electrical conductivity can be readilyachieved by addition of CNT to a polymer base, the subsequent effect onmechanical properties must be investigated. In this study, nanocomposite sampleswere manufactured using injection molding process. Multiwall Carbon Nanotube(MWCNT) masterbatch with 15 wt.% MWCNT concentrations were diluted withPA 6/6 pellets to create five different CNT concentration ranging from 3 wt.% in 3wt.% increments. The neat polymer sample was also manufactured as a controlspecimen. Mechanical properties such as Young’s modulus, Tensile strength andelongations were determined to see the effect of CNT content on overall properties.Scanning Electron Microscopy (SEM) images were used to evaluate the uniformdistribution of CNT in the polymer phase. The results showed that the stiffnessincreased as the CNT content increased, however, the increase in strength reached athreshold value around 6 wt.% beyond which the strength decreased. It wasobserved that the elongation decreased significantly by addition of CNT into thepolymer. The elongation dropped from an average of 190% for the neat sample to5% for 15 wt.% CNT content sample. Such decrease in elongation might render thepolymer unsuitable for the application it has been designed for. The findings of thisstudy show that improving thermal and electrical properties of polymers does notcome without a sacrifice on mechanical properties.