Synthesis of Copolymer of Aniline and Pyrrole by Inverted Emulsion Polymerization Method for Supercapacitor

Copolymer of aniline and pyrrole was synthesized by inverted emulsion polymerization method by oxidizing aniline and pyrrole using benzoyl peroxide in presence of sodium laurylsulphate surfactant and p-toluenesulphonic acid. Copolymer samples were characterized by infrared, X-ray diffraction and scanning electron microscopic techniques and compared their properties with the corresponding homopolymers. The optimum reaction conditions for the preparation of copolymer with reasonably good yield (1.72 g) and conductivity (7.3 x 10(-2) S/cm) were established. The synthesis procedure was extended to prepare copolymer samples using various protonic acids. Electrochemical characterization such as cyclic voltammetry, charge-discharge and impedance were carried out on symmetrical supercapacitor cell consists of poly(aniline-co-pyrrole)-p-toluenesulfonic acid salt, wherein, the copolymer salt was synthesized using equal amount of aniline and pyrrole monomers. The values of specific capacitance, energy and power densities for poly(aniline-co-pyrrole)-p-toluenesulfonic acid system (PANI-PPy) were calculated from charge-discharge studies and are found to be 21 F/g, 5.7 Wh/Kg and 100 W/Kg respectively. Impedance analysis showed specific capacitance value (57 F/g) at 0.01 Hz at 0.22 V. Among the copolymer salts, copolymer prepared with sulfuric acid showed higher capacitance (66 F/g). (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 115: 1695-1701, 2010