Dopamine-modified polyaspartic acid as a green corrosion inhibitor for mild steel in acid solution

Small-molecule organic corrosion inhibitors have attracted extensive attentions, but there are relatively few studies on corrosion inhibitors based on eco-friendly polymer materials. In the present work, dopamine modified polyaspartic acid (PASP-Dop) was well-designed and prepared. The inhibition ability of PASP-Dop towards mild steel was studied at various concentrations and temperatures using electrochemical measurement and weight-loss method. Investigations indicate that PASP-Dop has high corrosion inhibition performance for mild steel in acid solution due to the effective adsorption of PASP-Dop molecules at the metal/solution interface which is found to obey the Langmuir adsorption isotherm. From the potentiodynamic polarization measurements, the inhibition efficiency of PASP-Dop for mild steel in 0.5 M H2SO4 solution at a concentration of 100 ppm is up to 90.9% at 298 K. In addition, effect of temperature performed by weight-loss measurement reveals that PASP-Dop has good temperature adaptability. These results clearly demonstrate that as-synthesized eco-friendly polymer (PASP-Dop) is a high efficiency corrosion inhibitor with good application prospect.