DEVELOPMENT OF CONDUCTING COPOLYMER BASED ON POLY (O-TOLUIDINE-CO-2-AMINO 5 NAPTHOL 7 SULPHONIC ACID): AN EFFICIENT MATERIAL FOR PROTECTION OF IRON IN HIGHLY CORROSIVE ENVIRONMENT

Brij Mohan Singh Bisht, S.P.Gairola, Hema Bhandari, Sundeep K Dhawan

Abstract: The paper reports the corrosion inhibition performance of highly soluble conducting copolymer based on Poly(o-Toluidine-co-2- Amino-5-Naphthol-7-Sulphonic Acid). The copolymer was synthesized by in situ chemical oxidative polymerization method by taking different molar concentration of comonomers. Characterization of synthesized copolymer was carried out by using FTIR, TGA and SEM measurement. The corrosion inhibition behaviour of the copolymer in 1.0 M HCl has been evaluated using Tafel Extrapolation method, electrochemical impedance spectroscopy (EIS) and weight loss measurements. The results showed that the copolymer consists of higher concentration of naphthyl amine comonomer exhibited the significant shifting in the corrosion potential and greater charge transfer resistance in highly aggressive medium such as 1.0 M HCl. Maximum corrosion inhibition efficiency up to 95 % was obtained at 200 ppm concentration of the inhibitor. Moreover, the copolymer showed the larger degree of surface coverage onto the iron surface exhibits least corrosion rate, indicating the better protection of the iron in highly acidic medium.

Keywords: Conducting Copolymer, Corrosion Inhibitors, Tafel Plots, Impedance Spectroscopy

DOI: https://doi.org/10.15623/ijret.2016.0511009