Improvement of electrical conductivity with phase‐separation in polyolefin/multiwall carbon nanotube/polyethylene oxide composites

Electrical conductivity developments of polypropylene (PP)/multiwall carbon nanotube (MWNT) and polybutene (PB)/MWNT composites were carried out with polyethylene oxide (PEO) phase‐separation behavior for the polymeric materials. The low conductivity (8.47 × 10 −8 S cm −1 ) of PP(98%)/MWNT (2%) was drastically increased up to 1.56 × 10 −3 S cm −1 by only 2% PEO(96%)/MWNT(4%) loading. The drastic improvement originated from the formation of an electrical connector structure with the PEO/MWNT domain. The PB(93%)/MWNT(7%) conductivity was also improved by the PEO(92%)/MWNT(8%) loading although the conductivity improvement effect was lower than that of the PP/MWNT. The Raman spectra showed that the MWNT dispersity in the PB was poorer than that in the PP, resulting in the formation of a PEO/MWNT connector structure only at higher loading. In addition, a PEO/carbon black composite was able to produce the connector structure for the PP/MWNT as well as the PEO/MWNT. These results indicated that the highly conductive composites could be produced with smaller MWNT amounts. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013