SYNERGISTIC EFFECT OF HALIDE IONS ON THE CORROSION INHIBITION OF MILD STEEL IN SULPHURIC ACID USING METHYL, N-METHYL ETHYL AND ETHYL SUBSTITUTED gamma-2, c-6-DIPHENYL PIPERIDIN-4-ONE SEMICARBAZONES

摘要

The synergistic effect of halide ions such as KCl, KBr and KI on the corrosion inhibition of mild steel in 1 N sulphuric acid by gamma-2, c-6-diphenyl-t-3-methyl piperdin-4-ones with semicarbazone (01 SC), gamma-2, c-6-diphenyl-N-methyl-t-3-ethyl piperdin-4-ones with semicarbazone (02 SC) and 2,6-diphenylt-3-ethyl piperdin-4-one with semicarbazone (03 SC) has been examined by weight loss method, potentiodynamic polarization measurements and electrochemical AC impedance spectroscopy. Results show that substituted gamma-2, c-6-diphenyl piperidin-4-ones with semicarbazone act as the perfect corrosion inhibitors and their inhibition efficiency increases with the addition of halide ions. The inhibitor (01 SC) shows the inhibition efficiency of 78.28% (0.2 mM) by using a weight loss method. The influence of I-, Br- and Cl- anions raises the inhibition efficiency of the substituted 2,6-diphenyl piperidin-4-ones with semicarbazone due to the synergistic effect. The synergistic effect of halide ions was formed in the following order: KI KBr KCl.