Polysaccharide as Green Corrosion Inhibitor

The carbohydrates associated with polysaccharide glycosidic bonds are tightly chained, usually linear and highly branched complex molecules. Their structure mainly consists of hydroxyl groups in the form of functional groups, in which an oxygen heterogeneous atom is present. Some polysaccharides have hetero atoms. Nitrogen and Sulfur in addition to oxygen, which have unshared electron pairs. Hetero atoms easily share their electron pair to the vacant d orbitals of the metal ion and prevent the metal from corrosion. Polysaccharides are biodegradable, renewable, inexpensive and environment friendly due to which they are easily used as corrosion inhibitors. The present study mentions some major research work in which polysaccharides are used as corrosion inhibitors. Their mixed type nature has been reported in most research papers, and in the case of steel metal, they mainly follow the Langmuir adsorption isotherm. Chemical (gravimetric analysis) and electrochemical (EIS & PDP) studies are frequently used for the corrosion inhibition study. Some of the current research papers have also used computational or theoretical studies such as quantum chemical study and MD simulation. At the end of this book chapter, a discussion is also given regarding further research and direction related to the topic.