Investigation of Lignosulphonate Mannich Bases as Corrosion Inhibitors

To seek for new acidic corrosion inhibitor, this work used aliphatic amine, formaldehyde and sodium lignosulphonate as the raw materials to prepare new Mannich bases as eco-friendly corrosion inhibitors. The inhibition of these Mannich bases for mild steel corrosion in 2M HCl solution was investigated by weight loss technique. Through the single factor experiments, the optimal mole ratio was determined. Meanwhile, the influences of temperature and inhibitor dosage on the corrosion inhibition performance of the products were studied. The adsorptions on the surface of mild steel and inhibition mechanism were also discussed. Potentiodynamic polarization studies indicate that extracts are mixed-type inhibitors.