Ureidopyrimidinone-containing Poly(amino ester) for corrosion inhibition of mild steel in acidic medium

Ureidopyrimidinone-containing Poly(amino ester) (UPy-D400-PEGDA) was synthesized by the Michael addition reaction of Poly(ethylene glycol) diacrylate and polyether amine grafted 2-ureido-4[1H]-pyrimidinone motifs, and its corrosion inhibition efficiency on Q235 steel in 1 mol/L HCl medium was studied by polarization curve and electrochemical impedance spectroscopy, as well as corrosion product analysis. UPy-D400-PEGDA is a mixed-typed corrosion inhibitor that mainly suppressed the cathode, can form a protective film on the surface of mild steel to suppress the corrosion of oxygen and chlorine in acid medium. Corrosion inhibition efficiency was gradually enhanced with the increase of the concentration of UPy-D400-PEGDA. The corrosion inhibition efficiency reaches 98.80% when the inhibitor concentration is 500 mg/L. The surface roughness of mild steel in 1 mol/L HCl solution without UPy-D400-PEGDA was 3.891 μm, while the roughness of mild steel with UPy-D400-PEGDA concentration of 500 mg/L was only 0.636 μm. The inhibition mechanism was elucidated using quantum chemical calculation.