Binary Mixture of t(3)-Methyl-r(2),c(6)-diphenyl-piperidin-4-one and Gum Exudates of Astragalus genus as an Green Soldier for Dissolution Control of Mild Steel in HCl

Abstract

The corrosion inhibitive behaviour of t(3)-Methyl-r(2),c(6)-diphenyl-piperidin-4-one (3MDPP) and gum exudates of Astragalus genus (GTP) on mild steel in 1 N HCl were studied using weight loss measurements for 1 h immersion period at 303-323 K. The corrosion rate of mild steel directly varies with temperature whereas it varies inversely with concentration. The synergistic influence of different concen-trations of GTP on 3MDPP was analyzed at 303-323 K using weight loss technique. The icorr, Ecorr, Rct and Cdl values were obtained for 3MDPP, GTP and the mixture of GTP and 3MDPP (binary mixture). The calculated values of Ea, ΔH*, ΔS* and ΔG°ads suggests the physical adsorption mechanism and it obeys Langmuir isotherm. The synergistic influence of GTP on 3MDPP is clear from the synergistic parameter value (> 1).