ABSTRACT
The quest for sustainable and effective alternatives for industrial practices such as acid descaling, acid pickling, and acidization necessitates the adoption of corrosion control agents that are non-toxic, biodegradable, and environmentally friendly. Lignin and its derivatives are well-known biopolymers that can serve as replacements for their hazardous chromate counterparts with the potential of effectively mitigating the corrosion process at zero environmental impact. The ready availability, low cost, strong adsorption, and eco-friendly nature of lignin have drawn the attention of corrosion scientists and researchers in recent years. The chemical structure of lignin is furnished with numerous functional groups such as hydroxyl, carboxylic, phenolic, and methoxyl groups, which aid its interaction with metal surfaces and the formation of protective layers. The literature is replete with investigative studies showing the high performance of lignin as green chemical inhibitors in different metal systems and corrosive media. Experimental and computational results have demonstrated that lignin-based inhibitors can effectively reduce the corrosion rates of metals by deterring the penetration of corrosive species. This chapter provides a summary of recent research on lignin-based compounds as solution-phase corrosion inhibitors for metal protection.
