Polymerization of Aniline Using Iron(III) Catalyst and Ozone, and Kinetics of Oxidation Reactions in the Catalytic System

Abstract

The environmentally benign polymerization of aniline provided polyaniline with an emeraldine structure by using iron(III) and ozone which is easily converted from oxygen in air. The influence of the reaction temperature upon the molecular weight of the polyaniline in this system is different from that in the polymerization of aniline using ammonium peroxodisulfate as an oxidant. Although the polyaniline prepared here has low molecular weight, the low molecular weight of the polyaniline does not significanlty influence the electrical conductivity of cast films. In constrats, this can provide an advantage for the engineering of polyaniline through solution-processing. Kinetics of oxidation reactions in the polymerization, systematically investigated here, has revealed that polyaniline is produced catalytically in terms of iron(III) and that an oxidation reaction of iron(II) to iron(III) could be a rate-determining step in the polymerization.