The role of redispersible latex powder in various mortars
The redispersible latex powder can quickly redisperse into an emulsion after contacting with water, and has the same properties as the initial emulsion, that is, a film can be formed after the water evaporates. This film has high flexibility, high weather resistance and resistance to various High adhesion to substrates. In addition, the hydrophobic latex powder can make the mortar very waterproof.
The main application of redispersible latex powder
Internal and external wall putty powder, tile adhesive, tile pointing agent, dry powder interface agent, external thermal insulation mortar for external walls, self-leveling mortar, repair mortar, decorative mortar, waterproof mortar external thermal insulation dry-mixed mortar. In the mortar, it is to improve the brittleness, high elastic modulus and other weaknesses of the traditional cement mortar, and to endow the cement mortar with better flexibility and tensile bond strength, so as to resist and delay the generation of cement mortar cracks. Since the polymer and the mortar form an interpenetrating network structure, a continuous polymer film is formed in the pores, which strengthens the bonding between the aggregates and blocks some pores in the mortar, so the modified mortar after hardening is better than cement mortar. There is a big improvement.
The role of redispersible latex powder in mortar is mainly the following aspects
1 Improve the compressive strength and flexural strength of mortar.
2 The addition of latex powder increases the elongation of the mortar, thereby improving the impact toughness of the mortar, and also endows the mortar with a good stress dispersion effect.
3 Improve the bonding performance of mortar. The bonding mechanism is based on the adsorption and diffusion of macromolecules on the sticky surface. At the same time, the rubber powder has a certain permeability and fully infiltrates the surface of the base material with cellulose ether, so that the surface properties of the base and the new plaster are close, thereby improving Adsorption greatly increases its performance.
4 Reduce the elastic modulus of mortar, improve deformation ability and reduce cracking phenomenon.
5 Improve the wear resistance of mortar. The improvement of wear resistance is mainly due to the existence of a certain amount of glue on the surface of the mortar. The glue powder acts as a bond, and the omentum structure formed by the glue powder can pass through the holes and cracks in the cement mortar. Improves the bond between the base material and cement hydration products, thereby increasing wear resistance.
6 Give the mortar excellent alkali resistance.
7 Improve the cohesion of putty, excellent resistance, alkali resistance, wear resistance, and enhance the flexural strength.
8 Improve the waterproof and permeability of putty.
9 Improve the water retention of putty, increase the open time, and improve workability.
10 Improve the impact resistance of putty and enhance the durability of putty.
Redispersible latex powder is made of polymer emulsion by spray drying. After mixing with water in mortar, it is emulsified and dispersed in water to re-form a stable polymer emulsion. After redispersible latex powder is emulsified and dispersed in water, the water evaporates. The polymer film is formed in the mortar to improve the properties of the mortar. Different redispersible latex powders have different effects on the dry powder mortar.
Product properties of redispersible latex powder
Improve the bending strength and flexural strength of mortar
The polymer film formed by redispersible latex powder has good flexibility. Films are formed in the gaps and surfaces of cement mortar particles to form flexible connections. Heavy and brittle cement mortar becomes elastic. Mortar added with redispersible latex powder is several times higher in tensile and flexural resistance than ordinary mortar.
── Improve the bonding strength and cohesion of mortar
After the redispersible latex powder as an organic binder is formed into a film, it can form high tensile strength and bonding strength on different substrates. It plays an important role in the adhesion of mortar to organic materials (EPS, extruded foam board) and smooth surface substrates. The film-forming polymer rubber powder is distributed throughout the mortar system as a reinforcing material to increase the cohesion of the mortar.
──Improve the impact resistance, durability and wear resistance of mortar
The rubber powder particles fill the cavity of the mortar, the density of the mortar is increased, and the wear resistance is improved. Under the action of external force, it will produce relaxation without being destroyed. The polymer film can be permanently present in the mortar system.
──Improve the weather resistance and freeze-thaw resistance of mortar, and prevent mortar from cracking
Redispersible latex powder is a thermoplastic resin with good flexibility, which can make the mortar cope with the change of external cold and hot environment, and effectively prevent the mortar from cracking due to the change of temperature difference.
── Improve the hydrophobicity of mortar and reduce water absorption
The redispersible latex powder forms a film on the cavity and surface of the mortar, and the polymer film will not disperse again after being exposed to water, which prevents the intrusion of water and improves the impermeability. Special redispersible latex powder with hydrophobic effect, better hydrophobic effect.
── Improve the workability of mortar construction&
There is a lubricating effect between the polymer rubber powder particles, so that the mortar components can flow independently. At the same time, the rubber powder has an inductive effect on the air, giving the mortar compressibility and improving the construction workability of the mortar.
Product application of redispersible latex powder
1. Exterior wall insulation system
Adhesive mortar: ensure that the mortar will firmly bond the wall to the EPS board. Improve bond strength.
Plastering mortar: ensure the mechanical strength, crack resistance, durability and impact resistance of the thermal insulation system.
2. Tile adhesive and caulking agent
Tile Adhesive: Provides a high-strength bond to the mortar, giving the mortar enough flexibility to accommodate the different coefficients of thermal expansion of the substrate and tiles.
Sealant: Make the mortar have excellent impermeability and prevent the intrusion of water. At the same time, it has good adhesion, low shrinkage and flexibility to the edge of the tile.
3. Tiles refurbishment and wood plastering putty
Improve the adhesion and bonding strength of the putty on special substrates (such as tile surfaces, mosaics, plywood and other smooth surfaces), and ensure that the putty has good flexibility to strain the expansion coefficient of the substrate.
4. Putty for interior and exterior walls
Improve the bonding strength of the putty and ensure that the putty has a certain degree of flexibility to buffer the different expansion and contraction stresses produced by different base layers. Ensure that the putty has good aging resistance, impermeability and moisture resistance.
5. Self-leveling floor mortar
Ensure the matching of elastic modulus, bending resistance and crack resistance of mortar. Improve the wear resistance, bonding strength and cohesion of mortar.
6. Interface mortar
Improve the surface strength of the substrate and ensure the adhesion of the mortar.
7. Cement-based waterproof mortar
Ensure the waterproof performance of the mortar coating, and at the same time have good adhesion to the base surface, and improve the compressive and flexural strength of the mortar.
Eight, repair mortar
Ensure that the expansion coefficient of the mortar matches the base material and reduce the elastic modulus of the mortar. Make sure the mortar has sufficient water repellency, air permeability and cohesive force.
9. Masonry plastering mortar
Improves water retention.
Reduces water loss to porous substrates.
Improve the ease of construction operation and improve work efficiency.
Post time: May-09-2023