Grafted pectin as sustainable corrosion inhibitors

Pectins, originating from the Greek word "pektikos" signifying congealing, act as a component in the heteropolysaccharide family which exists primarily in the cell walls of terrestrial higher plants. Pectin contains rich ester and carboxyl groups that can exchange with water molecules on the metal surface to form a protective film, and thus meets the basic characteristics of corrosion inhibitors for various metals. However, most pectin exists in the form of original pectin with large molecular weight, poor solubility, and gelability. Therefore, modification of pectin to enhance its physiological function has become a research hotspot in recent years. This chapter describes the application of green, broad resource, and low-cost pectins and their derivatives in the inhibition of metal corrosion. Aspects of experimental and theoretical approaches about various sources of pectins and grafted derivatives, to a more intuitive way to understand the corrosion inhibitive processes have been elaborately reviewed.