Redispersible Polymer Powder (RDP), also known as redispersible latex powder, is a white free-flowing powder produced by spray-drying synthetic polymer emulsions. When mixed with water, it can re-disperse into a stable emulsion and form a continuous polymer film upon drying. As a key modification additive in dry-mix mortar, RDP powder significantly enhances bonding strength, flexibility, water resistance, and crack resistance.
RDP redispersible latex powder is produced from synthetic polymer emulsions (such as VAE, acrylics, etc.) with added protective colloids and anti-caking agents through spray-drying technology. After being mixed with water, the RDP powder can re-disperse into a polymer emulsion, and upon drying, it forms a continuous polymer film that provides bonding and modification functionality.
Product Specifications
Technical Date | S4012N | S5011N | S5220L | S8035H | S9028E |
Polymer Type | VAE | VAE | VAE | VA/VV/AC | S/AC |
Protective Colloid | PVA | PVA | PVA | PVA | PVA |
Solid Content% | ≥99 | ≥99 | ≥99 | ≥99 | ≥99 |
Ash content% | 14±2 | 12±2 | 12±2 | 12±2 | 12±2 |
Bulk density g/l | 400-600 | 400-600 | 400-600 | 400-600 | 400-600 |
Tg ℃ | 15 | 15 | 0 | -12 | 5 |
MFFT℃ | 4 | 4 | 0 | 0 | 1 |
PH value | 6-8 | 6-8 | 6-8 | 6-8 | 6-8 |
Type | Rigid | Rigid | Semi-Flexible | Flexible | Semi-Flexible |
Standard | High performance | Levelling | Hydrophobic type | Acrylic |
Performance Advantages of Redispersible Polymer Powder (RDP)
- Excellent Adhesion. It significantly improves the bonding between mortar and various substrates, including concrete, brick, insulation boards, gypsum boards, and ceramic tiles.
- Enhanced Flexibility & Crack Resistance. RDP redispersible polymer powder provides elasticity to accommodate substrate movements, effectively reducing the risk of cracking caused by shrinkage or thermal stress.
- Superior Water & Weather Resistance. This product forms a dense polymer network that enhances long-term durability, resists moisture penetration, and improves freeze–thaw stability.
- Improved Workability & Water Retention. Optimizes mortar flow and smoothness, extends open time, and reduces segregation and water bleeding during application.
- Anti-slip and Impact Resistance. Redispersible polymer powder (RDP) increases mechanical strength and stability in tile adhesive systems, minimizing tile slippage and improving overall performance.
- Tile Adhesives & Grouts. RDP powder is widely used in tile adhesives, including C1, C2, and flexible grades, as well as in tile joint fillers and grout systems. The polymer enhances bonding strength, flexibility, and slip resistance, improving overall tile installation performance.
- ETICS / EIFS External Insulation Systems. In external thermal insulation composite systems (ETICS/EIFS), RDP-modified mortars serve as adhesives for insulation boards and as base coats. The redispersible powder polymer improves crack resistance and provides long-term durability to render layers.
- Flooring Systems. RDP chemical is applied in self-leveling underlayments, repair mortars, and screeds, enhancing adhesion, flexibility, and durability of floor surfaces, while helping prevent shrinkage cracks and improving workability.
- Waterproofing Applications. Cement-based waterproof coatings, such as JS polymer mortars, benefit from RDP’s ability to form dense polymer films, which increase water resistance, reduce permeability, and improve freeze–thaw durability.
- Plaster & Decorative Mortars. RDP-modified plaster mortars, gypsum-based mortars, decorative colored mortars, and repair mortars gain improved adhesion, flexibility, and surface finish. The RDP polymer ensures crack resistance and enhances the overall durability and aesthetics of interior and exterior coatings.
- Polymer Resin. This is the primary functional component, responsible for the key performance of the RDP. Common types include Vinyl Acetate–Ethylene (VAE), Vinyl Acetate–VeoVa Copolymer (VA/VeoVa), acrylic copolymers, and Styrene–Butadiene Rubber (SBR).
- Protective Colloid. Typically polyvinyl alcohol (PVA), which prevents particle agglomeration and ensures that the powder can be easily redispersed into a stable emulsion.
- Anti-Caking Agents. Materials such as calcium carbonate and kaolin are added to maintain free-flowing properties and prevent clumping of the powder.
- Functional Additives. Optional additives, such as water repellents, defoamers, and other modifiers, are included to enhance or tailor specific performance characteristics.
Redispersible polymer powder (RDP) is incorporated into dry-mix mortar formulations together with cement, aggregates, fillers, and other additives. Upon the addition of water, the powder redistributes and forms a ready-to-use polymer-modified mortar with improved bonding, flexibility, and durability.
Recommended Dosage
(1) General modification: 1.5–6% by weight of the dry mortar, suitable for standard dry-mix applications.
(2) High-flexibility or insulation systems: 6–12% by weight of the dry mortar, ideal for applications requiring enhanced flexibility, crack resistance, or thermal insulation performance.
The exact dosage should be optimized according to the specific mortar formulation, substrate conditions, and desired performance requirements. Proper mixing ensures uniform dispersion of the polymer particles for maximum effectiveness.
- Polymer Emulsion Polymerization. Preparation of base emulsions such as VAE or acrylic copolymers with controlled particle size and solid content.
- Formulation and Mixing. Addition of protective colloids, anti-caking agents, and functional modifiers, followed by homogenized mixing to ensure uniform distribution.
- Spray Drying. The formulated emulsion is atomized into fine droplets and dried rapidly in a hot air stream, forming powder particles coated with protective colloid layers.
- Post-processing. Screening, cooling, and packaging are performed to achieve the desired particle size distribution, stability, and bulk density.
Buy High Quality RDP Chemical from Kingsun Factory
In conclusion, RDP redispersible polymer powder is a critical performance-enhancing component in construction mortar systems. It significantly improves bonding, flexibility, durability, workability, and water resistance, providing engineered solutions for modern high-performance construction materials. By the way, as a leading manufacturer and supplier of various construction chemicals in China, Kingsun factory always provides the competitive RDP powder price and excellent services for all the customers.