THE EFFECT OF SONICATION TIME AND DISPERSING MEDIUM ON THE MECHANICAL PROPERTIES OF MULTIWALLED CARBON NANOTUBE (MWCNT)/EPOXY COMPOSITE

This work describes the effect of sonication time and dispersing medium on the dispersion state of 0.1 wt.% MWCNT in a MWCNT/epoxy composite system. Epoxy, hardener, and epoxy/solvent were used as dispersing media in this study. Tensile strength, Young's modulus, and strain at failure were measured under different dispersion states of MWCNT. The results indicate that with increase in sonication time, initially there is an increase in tensile strength values, followed by a drop in values at longer sonication times. The highest Young's modulus values were seen in epoxy dispersion and the highest tensile strength value was observed when the hardener was used as dispersing medium. The results also indicated that the effect of sonication time was more pronounced for the case of epoxy dispersion. The effect of time was the shortest when the epoxy/solvent system was used as MWCNT dispersing medium. It should also be pointed out that Young's modulus for the nanocomposite sample obtained after 1 h of dispersion in hardener showed good agreement with a modified Halpin-Tsai theory. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to characterize the dispersion state of MWCNT. A good dispersion was obtained when either hardener or solvent was selected as the dispersing medium.