Modified Polyanilines via Electrochemical Copolymerization of Aniline and para‐phenylenediamine Derivatives

Abstract

Copolymerization of 2,5‐diaminobenzenesulfonic acid (DABSA) and para‐phenylenediamine (PPDA), respectively, with aniline (AN) was electrochemically performed by cyclic voltammetry on ‐coated electrodes in 1 M HCl. The copolymerization rate strongly depends on the amount of DABSA/PPDA in the comonomer feed. The composition analysis results indicate that the cross‐linking and branching reactions occur simultaneously during copolymerization at the fraction of DABSA larger than 0.206 in DABSA‐AN comonomer feed. The above‐mentioned two reactions exist in the PPDA‐AN copolymerization system at PPDA levels of 0.102 in comonomer feed. From x‐ray photoelectron spectroscopy results, the lines show that the net charge residing on the carbon atoms is affected neither by reaction time (cycle number) nor by the DABSA/PPDA fraction in the feed. The lines show that the second component peak corresonding to an amine site at 400.4 eV is more dominant for both DABSA and PPDA‐modified polyanilines. The composite film of DABSA/PPDA‐AN copolymer with waterborne polyurethane was prepared, and its conductivity measured to compare the effect of DABSA/PPDA in the comonomer feed. Stability testing shows DABSA‐AN copolymer film more stable than PPDA‐AN copolymer film. Electrochemical response of the modified polyaniline films to dissolved hydroquinone and was also examined.