Search

Conducting polymer composites, which are simply physical mixtures of an insulating polymer matrix and intrinsically conducting polymers, are promising new materials for various applications such as antistatic coatings, shielding and electromagnetic absorbers. In this context, a novel conducting composite was successfully produced. It is based on epoxy resin and polyaniline (PANI) doped in benzene sulfonic acid, which was used as conducting filler. The effect of PANI loading levels on the structural, morphological, thermal, electrical and dielectric properties was explored using techniques, such as Raman, Fourier transform infrared and ultraviolet-visible-NIR spectroscopy, X-ray diffraction, atomic force microscopy, scanning electron microscopy, thermogravimetric analysis and differential scanning calorimetry. The electrical behavior and morphology of the synthesized PANI revealed disorder and defects. In addition, as the applied voltage is increased, the current through the sample increases rapidly. The conductivity and dielectric properties were also investigated at room temperature in the frequency range of 1 MHz–1 GHz. The dielectric constant was shown to increase with increased loading at low frequencies and then decreases rapidly, reaching a constant value at higher frequencies. In addition, the AC conductivity of the prepared composites increases with the addition of PANI and is higher at high frequencies. Furthermore, the stability of the composites was found to be influenced by increasing the amount of PANI filler in the matrix. The defects and heterogeneous system of polyaniline (PANI) doped in benzene sulfonic acid (BSA) with a crystalline region dispersed in an amorphous low-conducting region as shown in the scanning electron microscopy micrograph reveal the current–voltage characteristic, which shows a nonohmic variation. It increases in current with applied voltage owing to the conduction mechanisms of PANI due to the formation of polarons and bipolarons. As the applied voltage increases, the formation of polarons and bipolarons increases rapidly, contributing to higher values of current through sample. This characteristic affects the dielectric behaviors of the elaborate composites.