Dispersion, migration, and ‘network‐like’ structure formation of multiwall carbon nanotubes in co‐continuous, binary immiscible blends of polyamide 6 and acrylonitrile–butadiene–styrene copolymer during simultaneous melt‐mixing

Abstract

Multiwall carbon nanotubes (MWNTs) were melt‐mixed in polyamide 6 (PA6) and acrylonitrile–butadiene–styrene (ABS) copolymer blends using a simultaneous mixing protocol in order to investigate the state of dispersion of MWNTs in PA6/ABS blends. The blend composition was varied from 40/60 (wt/wt) to 60/40 (wt/wt) in PA6/ABS blends, which showed ‘co‐continuous’ morphology in the presence of MWNTs. State of dispersion of MWNTs in these blends was assessed through bulk electrical conductivity measurements, morphological analysis, solution experiments, and UV‐vis spectroscopic analysis. MWNTs were subsequently modified with a novel organic modifier, sodium salt of 6‐aminohexanoic acid (Na‐AHA), to improve the state of dispersion of MWNTs. Blends with unmodified MWNTs exhibited the DC electrical conductivity in the range ∼10 −11 to ∼10 −5 S/cm, whereas blends with Na‐AHA‐modified MWNTs exhibited DC electrical conductivity in the range ∼10 −7 to ∼10 −5 S/cm. The reduction in MWNTs ‘agglomerate’ size (∼73.7 μm for 40/60 blend with unmodified MWNTs to ∼59.9 μm in the corresponding blend with Na‐AHA‐modified MWNTs) was observed through morphological analysis. The rheological studies showed increased complex viscosity and storage moduli in lower frequency region in case of blends with Na‐AHA‐modified MWNTs confirming a refined ‘network‐like’ structure of MWNTs. POLYM. ENG. SCI., 55:443–456, 2015. © 2014 Society of Plastics Engineers