Elucidation of Dimethyldodecylphosphonate and CTAB Synergism on Corrosion and Scale Inhibition of Mild Steel in Simulated Cooling Water System

The effect of dimethyldodecylphosphonate (DMDP) and Cetyltrimethylammonium bromide (CTAB) and the mixture of both (formulation), on mild steel corrosion in simulated cooling water, has been evaluated by means of electrochemical techniques such as polarization curves (I-E) and electrochemical impedance spectroscopy (EIS). Then the surface morphology was studied by scanning electron microscopy (SEM). The obtained results revealed that these compounds perform excellently as corrosion and scale inhibitors. The inhibition efficiency increases with circulation velocity rise and resisted to immersion time. Moreover, the inhibition efficiency was circa temperature-independent and retained its performance on a surface covered by corrosion products and though in very aggressive media such as 3% NaCl. These results were corroborated by SEM analyses which indicated a formation of a protective film formed on the mild steel surface by the proposed formulation.