New aryl-himachalene benzylamines derivatives as eco-friendly corrosion inhibitors at low concentration for brass 62/38 in 200 ppm NaCl: Experimental, analyses and theoretical approach

Abstract

This study investigates the inhibitory effect of eco-friendly synthesized aryl-himachalene benzylamines derivatives, namely (±)-N-((3,5,5,9-tetramethyl -6,7,8,9-tetrahydro-5H-benzo [7] annulen-2yl)methyl)aniline (AHB) and (±)-4-bromo-N-((3,5,5,9-tetramethyl-6,7,8,9-tetrahydro-5H-benzo[7]annulen-2-yl)methyl)aniline (AHBBR) at low concentration on the brass 62/38 (B62/38) corrosion in 200 ppm NaCl solution, employing electrochemical techniques, surface analyses and theoretical investigations. The experimental measurements indicated that these compounds exhibit as good inhibitions, where their inhibition efficiency growth with their concentrations, reaching 88.69 % and 93.35 % at 100 ppm AHB and AHBBR, respectively. I-E measurements designated that the tested products react like a mixed-inhibitor type. In addition, the EIS measurements showed the establishment of a protective layer on the B62/38 region. The effects of the temperature solution and immersion time on their performance were investigated. It is found that they decrease slowly with temperature, while they improve with the immersion time until 12 h. In the same way, it is found that these molecules react on B62/38 surface according to Langmuir isotherm adsorption. Complementary, SEM/EDX analysis established the development of an organic defending film on the B62/38 area, confirming the compound's potential as effective corrosion inhibitors. Finally, the theoretical investigations confirm the anti-corrosion character of the tested compounds according to their mode of adsorption.