RDP for Building and Construction Applications

30 May.,2022

Vinyl acetate-co-polyethylene copolymers (VAE) are white, free-flowing dry powders that can be easily redispersed into water to re-form a stable emulsion. Sometimes referred to as "solid latex", VAE redispersible powders (RDP) are easier to transport, store (excellent storage stability), handle and dry blend than VAE in emulsion form.

 

Vinyl acetate-co-polyethylene copolymers (VAE) are white, free-flowing dry powders that can be easily redispersed into water to re-form a stable emulsion. Sometimes referred to as "solid latex", Anionic Surfactantsare easier to transport, store (excellent storage stability), handle and dry blend than VAE in emulsion form. VAE represents the majority of the global market for redispersible polymer powders. 

 

Role and Function

Dry blending with other powders (such as cement, sand or light aggregates) in the field or at the manufacturing site promotes consistent and reliable performance. vAE-RDP is used as a cement and gypsum modifier or as a binder resin for inorganic materials such as gypsum and slaked lime. Formulators also use VAE-RDP as the sole binder resin for construction adhesives.

The advantages of adding VAE-RDP to dry blend formulations include improved workability and water retention, plasticity, dispersibility and freeze stability. Due to the relatively high ethylene content, VAE resins are soft and flexible. As a modifier, VAE-RDP improves flexural strength, crack resistance, adhesion, abrasion and impact resistance, and water resistance. 

Applications for VAE-RDP include the formulation of building materials such as tile adhesives, grout, finishing plasters, smoothing compounds, thin mortars, and sealing pastes. The amount of VAE-RDP added to cement and mortar is approximately 2-10%, depending on the desired strength, impact resistance, adhesion and water resistance improvement of the compound.

 

RDP for Building and Construction Applications

RDP for Concrete and Mortar


 
Manufacturing Process

Vinyl acetate and ethylene are copolymerized in an emulsion process that first produces a VAE composition with 10% to 40% ethylene content in the copolymer. Ethylene is a soft, hydrophobic monomeric unit in the copolymer that acts as the internal "plasticizing" part. In the copolymer, ethylene effectively lowers the glass transition temperature (Tg) of the hard polar vinyl acetate monomer to 30 °C. As a result, we can achieve copolymers with a Tg range of +15 °C to -15 °C, while converting the base emulsion resin used in VAE production into a redispersible powder. By using ethylene monomers to regulate Tg, the formulator does not need any external plasticizers.

 

RDP for Building and Construction Applications

 

Specialty Grades

The primary market for VAE RDP is the building and construction industry, where they are used to formulate dry blend products. The global market for these products is expected to grow by more than 7%. Technological developments in the field of thin layer tile adhesives are one of the drivers of growth. For wall tile adhesive applications, VAE-RDP improves slump, water retention and workability. This allows tiles to be laid from top to bottom without tile slippage or the need for shims. vAE-RDP also improves the leveling properties of tile adhesives and other cementitious materials. 
The demand for VAE-RDP has also grown into the area of surface coating compounds where VAE helps improve wall adhesion and crack bridging properties.

 

RDP for Building and Construction Applications

 

We designed this article to help those who wish to select the right VAE-RDP to enhance your specific adhesive, building compound or cement product. the professionals at TANGPENG are ready to assist you in your selection to ensure that you match the correct VAE-RDP to the performance requirements of your application. Get in touch today!