MODIFIED POLYANILINE THROUGH SIMULTANEOUS ELECTROCHEMICAL POLYMERIZATION OF ANILINE AND METANILIC ACID

Simultaneous electropolymerization of aniline and metanilic acid in aqueous HClO4 leads to a copolymer similar to that obtained by direct sulfonation of polyaniline. Characterization by electrochemical and spectroscopic methods (UV-visible, Fourier transform IR and proton NMR) indicated the presence of polyaniline linear chains in which metanilic acid units were inserted as spacers. Elemental analysis showed that the copolymer was 40% doped by the sulfonate side-groups intramolecularly (self-doping) and 20% doped by ClO4- intermolecularly. The presence of sulfonate functional groups decreased electronic conductivity and increased solubility in alkaline solvents, but the electrochemical properties remained principally that of polyaniline.