Control of multiwall carbon nanotubes dispersion in polyamide6 matrix: An assessment through electrical conductivity

The homogeneous dispersion of carbon nanotubes (CNT) remains a hindrance in exploiting the exceptional properties associated with CNT in polymer/CNT composites. Here we present for the first time the key role of sodium salt of 6-ammohexanoic acid (Na-AHA) in assisting debundling the multiwall carbon nanotubes (MWNT) through specific interactions leading to homogeneous dispersion within polyamide6 (PA6) matrix during melt-mixing. The composite fabricated via this route exhibits low electrical percolation threshold of 0.5 wt% at room temperature, the lowest reported value in this system so far. FTIR and Raman spectroscopy reveal the existence of 'cation-pi' interaction between Na-AHA and MWNT. The phenomenon of reactive coupling between amine functionality of NaAHA and acid end group of PA6 during melt-mixing is also established. (c) 2006 Elsevier B.V. All rights reserved.