Methylenedisalicylic Acid as a Biocorrosion Inhibitor for Aluminum in Concentrated Sodium Chloride Solutions.

3,3'-Methylenedisalicylic acid (MDS) was synthesized and ascertained on the basis of elemental analyses (C, H) and spectral measurements (IR, mass, H NMR, and UV-vis). Moreover, the prepared MDS compound has been assayed for its antimicrobial action against the growth of fungi as well as Gram-positive and Gram-negative bacteria. The results demonstrated the possibility of its usefulness to restrain the growth of both fungi and bacteria, whereas MDS showed its best impact against . The inhibitive impact of MDS on the corrosion of aluminum (Al) in concentrated sodium chloride solution (3.5 wt % NaCl) has been investigated. The corrosion work was done by potentiodynamic cyclic polarization, electrochemical impedance spectroscopy, and chronoamperometric current-time measurements and complemented by scanning electron microscopy and energy-dispersive X-ray investigations. It was found that MDS molecules protect the aluminum against corrosion, and its ability increases with the increase of concentration from 5 × 10 to 1 × 10 M and further to 5 × 10 M. The electrochemical results were supported by the morphological analysis and proved that the presence of MDS inhibits the uniform and pitting corrosion of Al in the chloride solutions.