The Synthesis and Properties of Novel Conducting Polyaniline and Poly [(nitrile butadiene-co-acrylonitrile)/Polyvinyl Chloride] Blends

Thin films of the blends of dodecylbenzenesulfonic acid (DBSA) doped polyaniline (PAni) and the commercial poly(butadiene-co-acrylonitrile)/poly(vinyl chloride) blend (ZeonNipol ® DN171) were prepared via co-dissolution, at varying ratios of conducting fillers (0.5-50 wt.%). Electrical conductivity measurements showed an increase in conductivity with increasing concentration of PAni-DBSA. At a percolation threshold of 0.9% (wt/wt), an increase in electrical conductivity of approximately four orders of magnitude ensued, with a recorded conductivity of 1.21 × 10 -4 S.cm -1 for the most conductive blend (consisting of 50 wt.% PAni-DBSA). Characterization by UV-visible spectroscopy indicated retention of the doped (conductive) state of the PAni-DBSA in each elastomeric blend. Morphological studies by optical microscopy showed the presence of PAni-DBSA agglomerate networks (or interpenetrating networks) at higher concentrations; however, at low concentrations of PAni-DBSA, the dispersion and encapsulation of the conductive species was observed. Due to the double-phase morphology of Nipol ® DN171, the encapsulation phenomenon may be attributed to the presence of the thermoplastic poly(vinyl chloride). Solubility parameter calculations confirmed the compatibility of PAni-DBSA with the constituents of the Nipol ® DN171 elastomer. This was supported by the infrared spectra, which showed the presence of functional groups specific to the reacting components of each blend. Thermal analysis, by DSC and TGA, indicated an increased thermal stability with increasing concentration of the elastomeric material.