The Role of Specific Interaction and Selective Localization of Multiwall Carbon Nanotubes on the Electrical Conductivity and Phase Morphology of Multicomponent Polymer Blends

Multicomponent polymer blends involving polyamide6 (PA6), polypropylene (PP), acrylonitrile-butadiene-styrene (ABS) and high density polyethylene (HDPE) with multiwall carbon nanotubes (MWNT) were prepared by melt mixing technique to achieve conducting composites. MWNT were either compounded directly or by employing a masterbatch dilution approach in binary (PA6/ABS), ternary (PA6/PP/ABS) and quaternary (PA6/PP/ABS/HDPE) blends. To facilitate network-like structure MWNT were pretreated with either sodium salt of 6-aminohexanoic acid or octadecyl tri-phenyl phosponium bromide. Multicomponent blends with pretreated MWNT utilizing masterbatch dilution approach showed significant improvements in the bulk electrical conductivity as compared to blends prepared by direct addition approach at 2 wt % MWNT content. Phase morphology of these blends revealed co-continuous type of morphology wherein MWNT were found to be selectively localized in the PA6 phase. The hetero-nucleating action of MWNT was manifested in increased crystallization temperature of mainly PA6 phase of the blends indicating preferential localization of MWNT in the PA6 phase. POLYM. ENG. SCI., 51:1987-2000, 2011. (C) 2011 Society of Plastics Engineers