Studies on chemical oxidative copolymerization of aniline and o-alkoxysulfonated anilines: I. Synthesis and characterization of novel self-doped polyanilines

The chemical oxidative copolymerization of aniline (An) with o-alkoxysulfon ated anilines, i.e., 1-(o-amino)-propane-3-sulfonic acid (APPrS) and 1-(o-a mino)-butane-3-sulfonic acid (APBuS), was a new way to produce water-solubl e and self-doped polyaniline derivatives. Poly(An-co-APPrS) and poly(An-co- APBuS) were obtained in H2SO4 acidic medium by chemical oxidation, using am monium persulfate, of a comonomer mixture containing An and APPrS, or APBuS , in various initial ratios. The copolymers thus obtained with high or low yields, were characterized by elemental microanalysis, FTIR spectroscopy, s ize exclusion chromatography and conductivity measurements. Due to the elec tron-donating effects of the alkoxysulfonated groups, the two aniline-deriv atives were easily incorporated in the macromolecular chains and strongly e nhanced water-solubility of the products. The electrical conductivities of these copolymers, which depend on both self- and external-dopings, were red uced by the incorporation of alkoxysulfonated substituents compared with th e one of parent polyaniline. (C) 1999 Elsevier Science S.A. All rights rese rved.