Degradation of Electrochemically Prepared Polypyrrole in Aqueous Sulfuric Acid

Detailed studies on the degradation reaction of electrochemically prepared polypyrrole have been conducted in an aqueous 1.0 M solution by anodic oxidation of the polymer film at platinum electrodes, and the results are reported. The degree of degradation was followed by recording cyclic voltammograms of polypyrrole films on the electrode as well as the absorbance of the resulting products in solutions. From ultraviolet, infrared, nuclear magnetic resonance, and mass spectra of the degradation product, we conclude that the major degradation product is a mixture of maleimide and succinimide with their respective ratio of about 7:1. A degradation reaction mechanism consistent with the degradation products is proposed.