Effect of 2-[substituted-hydrazine]carbothioamide as corrosion inhibitors for mild steel in sulphuric acid solution

Abstract

Prepared thiosemicarbazide derivatives (SB1, SB2, SB3, SB4 and SB5) were investigated as corrosion inhibitors for mild steel in 1M H2SO4 solution by weight loss measurements, the inhibition efficiency increased by increasing the inhibitor concentration, and the inhibition efficiency orders are SB1 > SB5 > SB3 > SB2 > SB4 with the highest inhibiting efficiency of 95.39% for 10−3M. The values of Goads showed physisorption effect for (SB1, SB2, SB4 and SB5) and chemisorption effect for SB3. Semiempirical molecular orbital calculations for (SB1, SB2, SB3, SB4 and SB5) gave useful information to explain the interaction between the surface of metal and the organic molecules.