Redispersible Polymer Powder Formula

Description

Redispersible Polymer Powder formula is a free-flowing, white powder obtained by spray-drying aqueous emulsions. These powders can be redispersed in water to form stable emulsions, exhibiting properties similar to the original latex before drying. RDPs are widely used as modifiers in various construction materials to enhance their performance characteristics.

Chemical Composition

RDPs are primarily based on polymers such as vinyl acetate-ethylene (VAE), vinyl ester of versatic acid (VeoVa), acrylics, styrene-butadiene, and other copolymers. They often contain protective colloids like polyvinyl alcohol (PVA) and anti-caking agents such as mineral fillers to ensure stability and ease of handling.

Key Properties

• Redispersibility: Ability to re-emulsify in water, forming stable latex with properties akin to the original polymer dispersion.
• Film Formation: Upon drying, RDPs coalesce to form a continuous polymer film, imparting flexibility and adhesion.
• Mechanical Strength: Enhances tensile and flexural strength of modified materials.
• Water Resistance: Improves resistance to water penetration and enhances durability.
• Workability: Improves the flow and application properties of cementitious mixtures.
• Freeze-Thaw Stability: Offers better resistance to cycles of freezing and thawing.

Applications

RDPs are extensively used in the construction industry, particularly in:

• Tile Adhesives and Grouts: Enhances adhesion, flexibility, and water retention.
• Self-Leveling Compounds: Improves flow, leveling properties, and surface strength.
• External Insulation and Finish Systems (EIFS): Provides flexibility and impact resistance.
• Skim Coats and Renders: Enhances workability and surface finish.
• Waterproofing Mortars: Improves water resistance and flexibility.
• Repair Mortars: Increases adhesion and durability.

Advantages

• Enhanced Adhesion: Provides superior bonding to various substrates.
• Flexibility: Reduces the risk of cracking by accommodating substrate movements.
• Improved Durability: Offers resistance against weathering, chemicals, and mechanical stresses.
• Ease of Use: As a powder, RDPs are easy to store, handle, and integrate into dry-mix formulations.

Redispersible Polymer Powder formula Typical Specifications

Property	Value
Appearance	White free-flowing powder
Solid Content	≥ 98%
Bulk Density	400 – 600 g/L
Particle Size	80% passes through 80 µm sieve
Minimum Film Forming Temperature (MFFT)	0 – 15°C (varies with type)
Glass Transition Temperature (Tg)	-10 to +20°C (varies with type)

Processing and Handling

• Storage: Store in a cool, dry place. High humidity and temperature can lead to caking.
• Shelf Life: Typically 12 months under proper storage conditions.
• Handling Precautions: Avoid inhalation of dust. Use appropriate personal protective equipment (PPE) during handling.

Leading Brands

Brand Name	Manufacturer	Polymer Base
VINNAPAS®	Wacker Chemie AG	VAE, Acrylics
ELOTEX®	Celanese Corporation	VAE, VeoVa, Acrylics
MOPITEC®	Hexion Inc.	Styrene-Butadiene
Dairen®	Dairen Chemical Corporation	VAE
DAITOSOL®	Daito Chemix Corporation	Acrylics
ROVACE®	H.B. Fuller	VAE

Environmental and Safety Considerations

RDPs are generally considered safe for use in construction materials. However, it’s essential to adhere to safety guidelines:

• Dust Control: Use dust extraction systems and PPE to prevent inhalation.
• Disposal: Dispose of in accordance with local regulations.

Product making Guide

Redispersible Polymer Powders are versatile additives that significantly enhance the performance of various cementitious and gypsum-based construction materials. Their ability to improve adhesion, flexibility, and durability makes them indispensable in modern construction practices.