Electrochemical synthesis of highly electroactive polydiphenylamine/polybenzidine copolymer in aqueous solutions

Poly(diphenylamine-co-benzidine) has been synthesized by electrochemical copolymerization of diphenylamine with benzidine in aqueous solutions. The composition of the copolymer and thus the electroactivity and conductivity of copolymer could be altered by variation of the comonomer feed ratios. The rate of copolymer formation is much higher than the homopolymerization. Electrochemical investigations indicate that reactivity of diphenyl amine for polymer formation is greater than that of benzidine, because of stability of diradical cations of benzidine. The copolymer which is formed under optimum conditions is much more electroactive than the corresponding homopolymers. Cyclic voltammetric studies show that the electroactivities of both benzidine and diphenyl amine moieties are apparent in copolymers.