Soluble polyanilines obtained by nucleophilic addition of arenesulphinic acids

Polyaniline powder and films can be modified by nucleophilic addition of arenesulphinic acids to oxidized forms of polyaniline. The FTIR spectra of modified polymers suggest the formation of sulphone and/or sulphonamide moieties linked to the polymer backbone. The modification degree increases with the increasing of the oxidation state of the polymer. The addition decreases significantly at pH above 7. It is proposed a mechanism of nucleophilic addition, which explains the effect of the oxidation state of the polymer and pH of the solution. The modification increases the solubility of the polymers in common organic solvents. The modification reaction seems to provide a simple pathway to the incorporation of organic moieties to polyaniline backbone.