Redispersible polymer powder is a type of polymer powder that is used as a binder in various applications, such as construction, ceramics, and coatings. The mechanism of action of redispersible polymer powder involves its ability to form a film when mixed with water. The powder particles are coated with a protective layer that prevents them from clumping together. When mixed with water, the protective layer dissolves, and the polymer particles disperse in the water. The polymer particles then coalesce to form a film, which provides the desired properties, such as adhesion, water resistance, and flexibility. The film-forming mechanism of redispersible polymer powder is based on the chemical and physical properties of the polymer, as well as the formulation and processing conditions.