Redispersible Polymer Powder (RDP) is a powdery substance made by drying polymer emulsion, which is commonly used in materials such as construction, coatings, adhesives, and tile adhesives. Its main function is to redisperse into emulsion by adding water, providing good adhesion, elasticity, water resistance, crack resistance, and weather resistance.
The composition of Redispersible Polymer Powder (RDP) can be analyzed from multiple aspects, mainly including the following components:
1. Polymer resin
The core component of Redispersible Polymer Powder is polymer resin, which is usually a polymer obtained by emulsion polymerization. Common polymer resins include:
Polyvinyl alcohol (PVA): has good adhesion and film-forming properties and is widely used in building materials.
Polyacrylates (such as polyacrylates, polyurethanes, etc.): have excellent elasticity, bonding strength, and water resistance.
Polystyrene (PS) or ethylene-vinyl acetate copolymer (EVA): commonly used to improve film-forming properties, increase water resistance, and weather resistance.
Polymethyl methacrylate (PMMA): This polymer has good anti-aging and transparency.
These polymer resins form emulsions through polymerization reactions, and then the water in the emulsion is removed by spray drying or freeze drying, and finally a Redispersible Polymer Powder (RDP) in powder form is obtained.
2. Surfactants
In order to maintain the stability between polymer particles and avoid agglomeration in the powder, an appropriate amount of surfactants will be added during the production process. The role of surfactants is to reduce the surface tension between particles and help the particles disperse in water. Common surfactants include:
Non-ionic surfactants (such as polyethers, polyethylene glycols, etc.).
Anionic surfactants (such as fatty acid salts, alkyl sulfonates, etc.).
These surfactants can enhance the dispersibility of Redispersible Polymer Powder (RDP)s, allowing the latex powder to re-form an emulsion after adding water.
3. Fillers and thickeners
In order to adjust the performance of latex powders and reduce costs, some fillers and thickeners may also be added during production. There are many types of fillers, and common ones include:
Calcium carbonate: a commonly used inorganic filler that can increase adhesion and improve cost-effectiveness.
Talc: can increase the fluidity and crack resistance of the material.
Silicate minerals: such as bentonite, expanded graphite, etc., can enhance the crack resistance and water resistance of the material.
Thickeners are usually used to adjust the viscosity of the product to adapt it to different construction conditions. Common thickeners include hydroxypropyl methylcellulose (HPMC) and polyvinyl alcohol (PVA).
4. Anti-caking agent
In powdered products, in order to prevent agglomeration during storage and transportation, anti-caking agents may also be added during the production process. Anti-caking agents are mainly some fine inorganic substances, such as aluminum silicate, silicon dioxide, etc. These substances can form a protective film on the surface of latex powder particles to prevent particles from agglomerating together.
5. Other additives
Redispersible Polymer Powder (RDP) may also contain some special additives to improve specific properties:
UV-resistant agent: improves the weather resistance and anti-aging ability of the material.
Antibacterial agent: reduces the growth of microorganisms, especially when used in a humid environment.
Plasticizer: improves the flexibility and crack resistance of latex powder.
Antifreeze: Prevent materials from freezing in low temperature environments, affecting construction and use effects.
6. Moisture
Although Redispersible Polymer Powder (RDP) is in the form of dry powder, it also requires a certain amount of moisture control during the production process, and the moisture content is usually controlled below 1%. Appropriate moisture content helps maintain the fluidity and long-term stability of the powder.
The role and performance of Redispersible Polymer Powder (RDP)
The key role of Redispersible Polymer Powder (RDP) is that it can be redispersed to form an emulsion after adding water, and has the following important performance characteristics:
Excellent adhesion: Enhance the bonding ability of coatings and adhesives, and improve the bonding strength between building materials.
Elasticity and flexibility: Improve the elasticity of the coating, enhance its crack resistance and impact resistance.
Water resistance: Enhance the water resistance of the material, suitable for use in outdoor or humid environments.
Weather resistance: Improve the material’s UV resistance, anti-aging and other properties, and extend its service life.
Crack resistance: It has good crack resistance and is suitable for anti-cracking needs in construction projects.
RDP is made by converting emulsion polymer into powder through a sophisticated process. It has many excellent properties and is widely used in construction, coatings, adhesives and other fields. The selection and proportion of its ingredients directly affect its final performance.
Post time: Mar-11-2025