Recent Trends in Waterborne and Bio-Based Polyurethane Coatings for Corrosion Protection

Polyurethanes (PUs) have been extensively exploited for the production of protective coatings thanks to the versatility of their chemistry, which allows to adjust the coating properties depending on the final application. In the last decade, the concerns on the negative impact on the environment and human health of traditional petroleum-based and solvent-borne PUs have fostered the research on more environmentally friendly alternatives. This review article provides an overview of the recent approaches that have been profitably pursued for the development of green PUs coatings for the protection of metal surfaces from corrosion. In particular, waterborne and bio-based polyurethane coatings are addressed, highlighting the main strategies adopted to enhance their anticorrosion ability. Finally, relevant data on the protective performances of green PU coatings are collected and critically discussed.