Multiwalled carbon nanotubes-incorporated polyurethane nanocomposites

Polyurethane was used as adhesive due to high reactivity, high flexibility, and mechanical properties. Electrically conductive adhesives (ECAs) are an alternative to tin-lead solder in order to provide conductive paths between two electrical device components, which typically consist of a polymeric resin that contributes physical and mechanical properties, and conductive fillers. However, ECAs have low electrical conductivity and unstable network due to large contact points of the few micrometer-sized metal particles. In order to overcome these restrictions, multiwalled carbon nanotubes (MWCNTs) with high aspect ratio and smaller nanometer scale can be used as conductive fillers. In this study, ECAs were based on polyurethane filled with two kinds of fillers, raw MWCNTs and acid treated MWCNTs, respectively. Electrical conductivity was measured by using four-point probe. Morphology and dispersibility of fillers were observed by scanning electron microscopy and transmission electron microscopy.