From Wet to Protective: Film Formation in Waterborne Coatings

The importance of anticorrosive coatings cannot be overstated, as they play a vital role in safeguarding assets and infrastructure across various industries. Within this context, the emergence of waterborne (WB) coatings stands out for their paramount significance, offering a sustainable alternative to traditional solvent-based (SB) coatings and addressing pressing environmental concerns. Despite their eco-friendliness, the complexity of their film formation mechanism and the lack of understanding present challenges in enhancing the performance of waterborne coatings for corrosion protection. These coatings are created by dispersing polymers in water, which then form a protective film on a substrate. The process involves stages like water evaporation, particle packing, and polymer interdiffusion, often leading to films with defects and inferior protection against extremely corrosive environments compared to SB coatings. This Review scrutinizes the interplay of factors affecting film formation in application, including coalescing agents, environmental factors, and application conditions. A comparative analysis between SB and WB coatings is also featured to shed light on the performance gap under harsh conditions. This Review discusses analytical techniques for studying film formation, aiming to guide future research toward improving WB coatings' durability and effectiveness. In compiling this collective wisdom, this Review emphasizes the translation of theoretical understanding into practical knowledge, equipping formulators with actionable insights to optimize WB coatings for real-world application and performance.