Chemical modification of of polypyrrole. I. Preparation and structural characterization of polypyrrole electrophically substituted with phthalic anhydride and pyromellitic dianhydride

Polypyrrole (PPY) prepared in ether and in aqueous medium has been modified by polycondensation with phthalic anhydride (PA) and pyromellitic dianhydride (PMDA) in presence of Friedel–Crafts catalysts such as anhydrous zinc chloride and anhydrous ferric chloride at high temperature. The substitution reaction between PPY and the anhydrides presumably proceeds by intra-and interchain resulting in the formation of intractable products. The characterstic carbonyl absorption band expected for CO and diketone groups in the proposed structure for the polycondensates has been observed in spectra of the anhydride-modified poly-condensates. XRD pattern of the polycondensates is totally amorphous. © 1994 John Wiley & Sons, Inc.