Evaluation of antioxidant activity of homo and copolymer of aniline and p-phenylenediamine electrosynthesized in the presence of calcium chloride

Homo and copolymer of aniline (Ani) and p-phenylenediamine (pPDA) are electrodeposited on the composite graphite (CG) in phosphoric acid (H3PO4) solution which contains calcium chloride (CaCl2) as the supporting electrolyte and different ratios of two monomers. The antioxidant activity is evaluated through the reaction of copolymers with 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical in methanol. The FTIR and UV–visible spectra indicate that the increase of the molar ratio of pPDA in polymer chain has also increased the antioxidant activity of the copolymers. The electrochemical impedance spectroscopy (EIS) is used for further investigation. It was revealed that the increase of the molar ratio of pPDA in polymeric chain decreased the charge transfer resistance (R ct) in the electrochemical content and improved the free radical scavenging activity of copolymers.