What is the process by which waterborne coatings cure?

Waterborne coatings cure primarily through a process known as coalescence. This involves the dispersal of polymer particles in the waterborne coating formulation. When the coating is applied, the water starts to evaporate, leading to an increase in temperature and the fusing of these polymer particles together. As the individual particles coalesce, they form a continuous film, which results in the hardening or curing of the coating.

Coalescence is particularly important in waterborne systems because, unlike solvent-borne coatings that may rely heavily on evaporation and chemical reactions, waterborne coatings utilize the ability of polymer particles to come together to form a solid layer. This process is essential for achieving the desired durability and aesthetic properties in the final coated surface.

Other processes, such as evaporation, oxidation, and polymerization, play roles in different types of coatings, but they do not directly describe the specific mechanism by which waterborne coatings cure. Evaporation mainly contributes to the reduction of water content but is not the curing mechanism itself, while polymerization and oxidation involve different chemical reactions not applicable to the curing of waterborne coatings.