Inhibition of mild steel corrosion in 1 M HCl by chondroitin sulfate and its synergistic effect with sodium alginate

The development of effective and environment-friendly corrosion inhibitors is of great significance for the protection of mild steel in hydrochloric acid media. Accordingly, a natural polysaccharide mixture inhibitor composed of chondroitin sulfate derived from pig cartilage (CS-PC) and sodium alginate (SA) is developed here, and the synergistic effect of the two polysaccharides towards adsorption on mild steel in 1 M HCl is studied. The inhibition performance has been studied using weight loss test, electrochemical investigations, SEM, SECM and UV methods. The results indicate that the mixtures of CS-PC and SA strongly inhibit the corrosion of mild steel compared to individual inhibitors (i.e., 95.18 % versus 72.78 %), and show a synergistic inhibition effect. The structure-activity relationship between the molecular structure of the CS-PC + SA mixture and its corrosion inhibition performance has been discussed by using the quantum chemistry calculation and molecular dynamics simulations. It is believed that these results have certain guiding significance for the rational design of efficient corrosion inhibitor.

Automated summary

In this study, a natural polysaccharide mixture inhibitor composed of chondroitin sulfate derived from pig cartilage (CS-PC) and sodium alginate (SA) was developed for the protection of mild steel in hydrochloric acid media. The synergistic effect of the two polysaccharides towards adsorption on mild steel in 1 M HCl was investigated using various methods such as weight loss test, electrochemical investigations, SEM, SECM, and UV methods. The results demonstrated a strong inhibition performance and a synergistic effect of the CS-PC and SA mixture, compared to individual inhibitors, with potential guiding significance for the rational design of efficient corrosion inhibitors.