Rheological behavior, electrical conductivity, and morphology of multi-walled carbon nanotube filled poly(ethylene-co-vinyl acetate)/poly(methyl methacrylate) nanocomposites: Effect of nanofiller content

摘要

Nanocomposites derived from poly(methyl methacrylate) (PMMA) and poly(ethylene-co-vinyl acetate) (EVA) with 30 wt% EVA and 0-10 wt% multi-walled carbon nanotube (MWCNT) content were prepared. Scanning electron microscope images showed a two-phase morphology for the unfilled blend in which the EVA droplets were dispersed within the PMMA domain. However, the size of EVA droplets was considerably smaller in the nanocomposites than that of the unfilled blend. The tensile results revealed that the maximum elastic modulus, tensile strength, yield stress, and strain at break were achieved for the nanocomposite containing 5 wt% MWCNT. The electrical conductivity sharply increased for the nanocomposite containing 2.5 wt% MWCNT, in comparison with that of the unfilled blend, beyond which the conductivity was less dependent on the MWCNT content. The rheological characterization showed that the normalized relaxation time increased up to 5 wt% nanofiller and remained reasonably constant for higher amounts of MWCNT.