The Role of Redispersible Latex Powder in Mortar
Release Time:
2021-03-23
Source:
Dispersible latex powder is added to mortars to mitigate the inherent drawbacks of conventional cement-based mortars, such as brittleness and high elastic modulus.
The function of redispersible latex powder:
In mortar applications, the primary objective is to mitigate the inherent drawbacks of conventional cement mortar—such as its brittleness and high elastic modulus—by imparting superior flexibility and enhanced tensile bond strength. This helps to resist and retard crack formation in the mortar. The polymer forms an interpenetrating network structure within the mortar, creating a continuous polymer film in the pore spaces that strengthens the bonding between aggregates and seals some of the internal pores. As a result, the hardened modified mortar exhibits significantly improved performance compared with conventional cement mortar.
1. Redispersible latex powder forms a film upon redispersion and acts as a secondary adhesive to provide reinforcement;
2. The protective colloid is absorbed by the mortar system (and, once a film has formed, it is not degraded by water or undergoes “secondary dispersion”);
3. The film-forming polymer resin is dispersed throughout the entire mortar system as a reinforcing material, thereby enhancing the mortar’s cohesion.
In wet mortar
Enhance construction performance; improve flow properties; increase thixotropy and anti-sagging performance; enhance cohesion; extend open time; and improve water retention.
After the mortar has cured
Enhance tensile strength; increase flexural strength; reduce the elastic modulus; improve deformability; increase material density; enhance wear resistance; improve cohesive strength; decrease carbonation depth; reduce water absorption; impart excellent water-repellent properties to the material (by incorporating water-repellent polymer powder).
