Adopting a multipurpose inhibitor to control corrosion of ferrous alloys in cooling water systems

The heterocyclic compounds; 2,5-diphenylpyrazolo[1,5-c]pyrimidine-7(6H)thione (Phenyl), 5-methoxyphenyl-2-phenylpyrazolo[1,5-c]pyrimidine-7(6H)thione (Methoxy), 5-tolyl-2-phenylpyrazolo[1,5-c]pyrimidine-7(6H)thione (Tolyl), 5-tolyl-2-phenylpyrazolo[1,5-c]pyrimidine-7(6H)one (Inon), 2,5-diphenyl-3-iodopyrazolo[1,5-c]pyrimidine-7(6H)thione (Iodo) and 2,5-diphenyl-3-bromopyrazolo[1,5-c]pyrimidine-7(6H)thione (Bromo) were screened by Tafel Extrapolation and Linear Polarization Resistance techniques to detect the possibility of inhibition the uniform corrosion of carbon steel in stagnant cooling water containing 200 ppm chloride at 25 °C. The inhibition efficiencies of the studied compounds were found to decrease in the following order: Tolyl > Methoxy > Phenyl > Iodo > Bromo > Inon.