Ash Content in Redispersible Polymer Powder (RDP)

Redispersible Polymer Powder (RDP) is a high-performance polymer powder widely used in construction, coatings, and paper industries. It is primarily composed of vinyl acetate ester copolymers (VAE), offering excellent water dispersibility, alkali resistance, and film-forming properties. RDP is commonly used in cement-based mortars, tile adhesives, wall putties, waterproofing mortars, and other construction applications. It enhances adhesion, flexibility, and weather resistance.

Ash Content in RDP

Ash is an important indicator in RDP, typically referring to the inorganic residue remaining after the material is burned at high temperatures (e.g., 1000°C). The ash content directly affects the purity, thermal stability, and compatibility of RDP with other materials.

Sources of Ash in RDP

1. Impurities in the polymer raw materials: Impurities such as metal ions or unreacted monomers may be introduced during the polymerization process.

2. Protective colloids: RDP often uses polyvinyl alcohol (PVA) as a protective colloid, which may contain inorganic components that convert to ash upon heating.

3. Additives: To improve flowability, anti-caking properties, or other performance characteristics, inorganic additives may be added, which can contribute to ash formation.

Impact of Ash Content

The ash content can influence RDP performance in the following ways:

1. Thermal Stability: Higher ash content may lead to decomposition or carbonization of RDP at high temperatures, affecting its thermal stability.

2. Compatibility with Cementitious Materials: The inorganic components in ash may react with calcium oxide or magnesium oxide in cement, potentially affecting the dispersion and film-forming properties of RDP.

3. Product Purity: Excess ash may reduce the purity of RDP, which can impact its performance in coatings, adhesives, and other applications.

Methods for Determining Ash Content

The ash content is typically determined using the high-temperature incineration method, where the sample is heated to 1000°C in a muffle furnace, and the residual mass is measured. This method is simple and effective for assessing the purity of RDP.

Summary

The ash content in RDP is a critical factor that affects its performance. It generally ranges from 8% to 15%, depending on the product. The main sources of ash include impurities in the polymer, protective colloids, and additives. High ash content can negatively impact the thermal stability, compatibility with cementitious materials, and overall purity of RDP. Therefore, it is important to consider the ash content when selecting and using RDP in various applications.

Name: Owen Liu

E-Mail: owen.liu@jtdf-rdp.com

Mobile:+86 173 0070 4911（Whatsapp）