The Role of Redispersible Latex Powder in Mortar
Release Time:
2016-08-17
Source:
The Role of Redispersible Latex Powder in Mortar
Redispersible Latex Powder Role in mortar
Enhancing the flexural strength and bending resistance of mortar
Enhance the bond strength and cohesion of mortar
Enhance the impact resistance, wear resistance, and durability of mortar.
Enhance the mortar’s weather resistance, freeze-thaw durability, and crack resistance.
Enhance the hydrophobicity of mortar and reduce its water absorption.
Improve the workability of mortar during construction
After water is added and the dry-mixed mortar containing redispersible latex powder is mixed, the modification of cement mortar by the redispersible latex powder is achieved through the redispersion of the latex powder, the hydration of cement, and the film-forming process of the latex. The film formation of redispersible latex powder in the mortar generally proceeds in three stages:
① After water is added to the mortar and it is mixed, the polymer latex powder is uniformly redispersed throughout the fresh cement mortar, resulting in re-emulsification.
② Due to cement hydration, surface evaporation, and absorption by the substrate, the free water in the pores of the mortar is continuously depleted, thereby increasingly restricting the mobility of latex particles. The interfacial tension between water and air drives these particles to gradually align within the capillaries of the cement mortar or at the interface between the mortar and the substrate. As the latex particles come into contact with one another, the network-like moisture trapped between them evaporates through capillary action. The resulting high capillary tension exerts pressure on the surfaces of the latex particles, causing deformation of the latex colloidal system and promoting their coalescence; at this point, a latex film is essentially formed.
③ Through the diffusion of polymer molecules, latex particles form a water-insoluble continuous film within the mortar, thereby enhancing interfacial adhesion and modifying the mortar itself.
