Corrosion Inhibition of Polyethylene Glycol on Carbon Steel in Sulfuric Acid Solutions and its Synergism with Schiff Base

The inhibiting action of Schiff base and polyethylene glycol (Salpn-PEG) complexes on low-carbon steel corrosion in 0.5 M sulfuric acid was examined using weight loss, potentiodynamic polarization and spectroscopy electrochemical impedance (EIS) techniques. Schiff base N, N’-bis(salicyladehyde)-1,3-diaminopropane (Salpn) was synthesized by salicylaldehyde and 1,3- diaminopropane. PEG/Salpn complex with weight ratio 1:4, 2:4 and 3:4 of Salpn and PEG were prepared in methylene chloride solvent by a simple deporotonation procedure. Obtained Results show that PEG/IMZ complex is very effective corrosion inhibitor of carbon steel in the acid environment in compare with PEG, Salpn and noncomplex form of them. Maximum corrosion inhibition was obtained for PEG/Salpn complex with weight ratio 1:4 of Salpn and PEG. The inhibition efficiency increased with the increase in the temperature up to 45°C and decrease in higher temperatures. Results from all the corrosion tests were examined using SEM and are in reasonable good agreement. Adsorption thermodynamic data (〖K 〗_ads and 〖∆G〗_ads ) was calculated using the weight loss data