Assessment of intertube interactions in different functionalized multiwalled carbon nanotubes incorporated in a phenoxy resin

Abstract

AbstractIn this work, about 1 wt% of different functionalized carbon nanotubes (CNTs), namely CNTCOOH (CNT with carboxylic groups), CNTNH2 (CNT with amine groups) and CNTOH (CNT with hydroxyl groups), as well as nonfunctionalized CNTs were incorporated into a phenoxy resin via a melt mixing process. The extent of intertubes and polymer–tubes interactions and their influence on state of CNTs dispersion were assessed through determination of electrical, rheological, and morphological characteristics. CNTNH2 showed the lowest intertubes interactions followed by CNTOH and CNTCOOH. Nanocomposite made from CNTCOOH showed the poorest state of CNTs dispersion and the biggest CNTs agglomerates and it remained nonconductive. The acid‐functionalized CNTs were not able to form strong polymer–tube interactions because of their high cohesive energy and therefore in the melt rheological investigations they exhibited the lowest storage modulus and complex viscosity as well as the highest loss factor among all the studied CNTs. A good balance between intertubes and polymer–tube interactions is necessary through proper selection of CNTs functional groups for achieving a good state of CNTs dispersion and consequently obtaining enhanced electrical and viscoelastic properties. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers