Morphology and electrical conductivity of ternary polymer blends involving liquid crystalline polymer containing carbon nanotubes

Multi-walled carbon nanotubes (MWCNTs) were melt-mixed with the liquid crystalline polymer (LCP) phase to investigate MWCNTs dispersion and the electrical conductivity of LCP/MWCNTs composite. LCP/MWCNTs composite showed an insulating behavior even at 5 wt% of MWCNTs concentration, wherein MWCNTs were dispersed as ‘individualized’ as well as ‘nano-agglomerated’ state in the LCP matrix. Further, LCP along with MWCNTs were melt-mixed with 50/50 (wt/wt) polyamide 6 (PA6)/ acrylonitrile butadiene styrene copolymer (ABS) and 50/50 (wt/wt) polyamide 66 (PA66)/ABS blends. Morphological observations showed that MWCNTs were preferentially dispersed in the polyamide (PA) phase, which led to the refinement of the ‘co-continuous’ morphology. The electrical conductivity results showed that the theoretical electrical percolation thresholds of 0.9, 1.1 and 1.5 wt% of MWCNTs were achieved in the corresponding 90/10 (PA6/ABS)/LCP+MWCNTs, 95/5 (PA6/ABS)/LCP+MWCNTs and 95/5 (PA66/ABS)/LCP+MWCNTs blends. The lower melt-viscosity associated with the PA phase led to the preferential localization of the MWCNTs in the PA phase. This strategy led to finer network structure of MWCNTs selectively in the PA phase of the ‘co-continuous’ blend.