Specific interactions induced dispersion and confinement of multi-walled carbon nanotubes in co-continuous polymer blends

Abstract

Multiwall carbon nanotubes (MWNT) were melt-mixed with 50/50 co-continuous blends of polyamide 6 (PA6) and acrylonitrile-butadiene-styrene (ABS). Blending sequence and moulding processes were found to have a strong impact on the conductivity of the blends with MWNT Aggregated nature of the tubes, migration during processing and skin-core morphology generated during mould cooling step were found to be crucial parameters affecting the electrical conductivity of the blends. We report here the role of a reactive modifier: sodium salt of 6-amino hexanoic acid (Na-AHA) aiding in uniform dispersion of the MWNT in the 50/50 PA6/ABS blends and restricting the tubes utilizing specific interactions during melt-mixing in the PA6 phase in the blends. We further varied the MWNT to Na-AHA ratio from 1:1 to 1:15 to optimize the concentration of MWNT required in achieving lower electrical percolation threshold in co-continuous PA6/ABS blends. The associated percolation threshold was observed at similar to 0.5 wt% MWNT with high dielectric constant.