Synthesis and comparative study of corrosion inhibition ability of two polymeric compounds for carbon steel in 3.5% NaCl solution

Water soluble Urea Formaldehyde (UF) and Melamine Formaldehyde (MF) were synthesized and their corrosion inhibition behavior was studied for carbon steel in 3.5% NaCl solution by electrochemical techniques such as Tafel extrapolation and electrochemical impedance spectroscopy (EIS). The corrosion inhibition efficiency of this class of compounds has been determined for the first time. The corrosion behavior of UF and MF were found to be strongly dependent on the electric nature of the functional groups, which are presented in their chemical structure. Polarization measurements indicated that these two compounds reduce the corrosion rate by forming a protective thin layer on the metal surface. The optimum concentration of UF and MF in the solution which leads gaining the best corrosion inhibition were 100 ppm and 300 ppm respectively. The Scanning Electron Microscope (SEM) was used to investigate the surface morphology of specimens in the absence and presence of inhibitor compounds. All tests indicate that both UF and MF compounds, in low concentration, are suitable corrosion inhibitors for steel in 3.5% NaCl solution

Keywords:

Corrosion inhibitors , electrolyte , concentration , chemical nature , film forming corrosion inhibitor , water soluble compound