Apostichopus japonicus polysaccharide as efficient sustainable inhibitor for mild steel against hydrochloric acid corrosion

A bio-friendly polysaccharide from Apostichopus japonicus (AJPS) was evaluated as a potential inhibitor using weight loss test, electrochemical investigations, SEM and AFM methods. Weight loss measurement exhibited the percentage inhibition efficiency of 96.03% for AJPS and in the optimum concentration of 625 mg/L at 35 °C. Polarization diagrams revealed that the AJPS behaved as a mixed type inhibitor and mainly inhibited the anodic process. The inhibition performance of AJPS was optimized by factorial experimental designs, the optimized conditions for the minimum corrosion rate were CAJPS = 625 mg/L, t = 7 h, T = 35 °C. surface morphology by SEM and AFM confirmed the effectiveness of the inhibitor.