Kinetic study of pyrrole polymerization with iron (III) chloride in water

The chemical synthesis of polypyrrole in water, with FeCl3 as an oxidant of pyrrole, was investigated. During these experiments in ambient air, a large evaporation of pyrrole was observed. Moreover, a kinetic study of pyrrole disappearance by high-performance liquid chromatography (HPLC), with various FeCl3 concentrations, proved that the polymerization is first order with respect to the pyrrole and second order with respect to the FeCl3. These kinetics can be explained by the formation of an intermediary FeCl3–pyrrole complex as the first step of the polymerization. The second step, which is rate-determining, is the pyrrole oxidation by FeCl3, © 1994 John Wiley & Sons, Inc.