Electrical and structural analysis of conductive polyaniline/polyacrylonitrile composites

Conducting composites of polyacrylonitrile (PAN) copolymer containing 10% mass ratio methylacrylate and dodecylbenzene sulfonic acid doped polyaniline (PANI–DBSA) were prepared by solution blending. Electrical properties of the blends were characterized by means of electrical conductivity measurements and the phase structures were investigated via scanning electron microscopy (SEM), X-ray diffraction (XRD), FT-IR spectroscopy, differential scanning calorimetry (DSC) and dynamical mechanical analysis (DMA). It was found that the electrical conductivity of the composites increased with the increase of PANI–DBSA content and the percolation threshold lay around 3.2 wt%. DSC and DMA measurements showed that there was only one Tg for each blend and the values of Tg varied with the PANI–DBSA content, implying that the PANI–DBSA/PAN blend was at least partially compatible. The formation of the hydrogen bonding between the carbonyl groups in PAN copolymer and the imine groups in PANI–DBSA was identified by the FT-IR spectra. XRD demonstrated that the intrinsic layered arrangement of PANI–DBSA was disaggregated in the blends. Nanosize network structure of PANI–DBSA dispersing in PAN matrix and the so-called phase reverse occurring in the skin layer of the film samples at low PANI–DBSA loading were observed by SEM.