Dispersion Quantification and Mechanical Properties of MWCNT/Epoxy Nanocomposite for Different Processing Conditions

Abstract

In this work, multiwalled carbon nanotubes were dispersed in epoxy resin using high shear homogenizer. Two parameters were varied: homogenizing speed (7,500 rpm or 15,000 rpm) and homogenization time (5 min or 10 min). The effect of these varying parameters on the dispersion of MWCNTs in epoxy matrix and mechanical properties of nanocomposites has been quantified. The results indicate that the nanocomposite samples fabricated at 15,000 rpm for 5 min. exhibit highest Young’s modulus and tensile strength values, which is attributed to good dispersion of MWCNT as is shown by value of high composite index. However, the values of Young’s modulus and tensile strength decrease with a further increase in homogenization time due to possible nanotube damage. The flexural modulus and bending strength remain unaffected with the homogenization conditions. SEM studies and dispersion quantification indicated that nanocomposite samples prepared at 15,000 rpm and 5 min. as well as that prepared at 7,500 rpm and 10 min., showed higher compIndex values i.e. good dispersion. Hence, composite index values indicated good dispersion both at “high homogenizing speed, short duration” and “low homogenizing speed, long duration”.