Evaluating two new sulphonamidoimidazolines on the corrosion of brass in 0.6 M aqueous sodium chloride solution

摘要

Two properly substituted sulphonamidoimidazolines suitable for chelation have been synthesized from aspartic acid. The structures of these compounds have been established on the basis of their elemental analysis, synthetic route, IR, NMR and pK* values. The inhibiting action of the imidazoline derivatives namely α-benzenesulphonamido-β-(2-imidazolynyl) ethanoic acid (R_mH) and 1-benzenesulphonamido-1, 2-bis (2-imidazolynyl) ethane (R_bH) on the corrosion of brass in 0.6 M aqueous NaCl solution have been studied. R_bH is found to be a better inhibitor than R_mH. Difference in inhibition efficiency between R_mH and R_bH is correlated with their chemical structures. It has been observed that in presence of cysteine, inhibition efficiency of R_mH is increased.