An appraisal of the utilization of natural gums as corrosion inhibitors: prospects, challenges, and future perspectives

Natural gums are macro compounds containing monosaccharide (sugar) units bonded by glycosidic to form long polymeric sugar chains of considerably high molecular weight. Natural gums are multifaceted in applications with the main areas being the food and pharmaceutical industries. The recent research interest in corrosion inhibitors is considering natural gums because of their abundance and ecological compatibility. Hence, this review takes a look at the use of natural gums in pure and modified forms in metals protection. The review establishes that the corrosion-protecting ability of natural gums has a direct connotation with their macromolecular weights, chemical composition, and molecular and electronic structures. Immersion duration and temperature are other factors found to affect the inhibition performance of natural gums considerably. The inhibition of natural gums in pure form is found not to be excellent due to their high hydration rate, algal and microbial contamination, solubility that depends on pH, and thermal instability. Common modification techniques adopted by corrosion inhibitor scientists are copolymerization, mixing with chemicals to induce synergism, crosslinking, and insertion of inorganic nanomaterials into the polymer matrix. Infusion of biosynthesized nanoparticles approach towards enhancing the corrosion inhibition efficiency of natural gums is recommended for future studies because of the unique characteristics of nanoparticles.