What roles does redispersible polymer powder play in mortar?

he roles that redispersible polymer powder plays in mortar can be considered as follows.

First, after water added into mortar, the powder particles will get dispersed in water and quickly form a film under the action of hydrophilic protective colloid and mechanical shear force, causing an increase in the air content of mortar and helping enhance the construction liquidity of mortar.

Second, with the consumption of water, including evaporation and consumption due to hydration of inorganic cementitious materials, resin particles gradually get close, the interface gradually blurred, and resins overlapped. An appropriate amount of polymer powder can form a continuous polymer thin film, and form the framework system from inorganic and organic binders, i.e., the brittle framework formed by hydraulic. The frame system constituted by the film formation of polymer resin film in the gap with the aggregate particle surface, due to the improvement of polymer flexibility and deformability, enables the mortar to enhance the deformation capacity and increase the bonding capacity on the whole.