It problem the doped copolymer of o-aminophenol co

It was found that the existence of aminophenol and ortho toluidine monomers in the copolymer unveiled remarkable anticorrosive performance for MS. The corrosion inhibition performance of iron increases with increasing the concentration of poly (o-aminophenol-co-o-toluidine) inhibitor from 50-200ppm. The corrosion inhibition of pOAPOT mainly depends on the ? electron conjugation, molecular size, a quaternary nitrogen atom, an oxygen atom, and their solubility23. In general aniline homopolymers, as a corrosion inhibitor for iron in acid medium is restricted due to its insolubility in common organic solvent. To overcome this problem the doped copolymer of o-aminophenol co o-toluidine is chosen for corrosion inhibition of iron in a corrosive medium. The inhibition performance of pOAPOT is explained based on the molecular adsorption mechanism. The copolymer has two heteroatoms oxygen and nitrogen containing a lone pair of electrons is responsible for the enhancement of corrosion inhibition performance of iron in a corrosive medium. The copolymer adsorbed on the cathodic sites of the metal surface through electrostatic interaction thereby decreases the evolution of hydrogen. The adsorption on the anodic sites occurs through ? electrons of benzenoid and quinonoid rings in the copolymer and lone pairs of electrons of oxygen and nitrogen atoms, which decreases the anodic dissolution of metal. It is well known that presence of delocalized ? electrons, a quaternary nitrogen atom, oxygen atom act as bonding sites quaternary nitrogen atom, an oxygen atom, inductive effect of a methyl group and also recognized that bulkiness of substitution in aromatic ring results in good coverage of metal surface and enhance inhibition efficiency24. The results obtained from impedance, Tafel experimental values, the copolymer pOAPOT shows potent corrosion inhibition character in acid media.