Redispersible polymer powder is a water-soluble redispersible powder, the most common is ethylene-vinyl acetate copolymer, and uses polyvinyl alcohol as a protective colloid. Therefore, redispersible polymer powder is very popular in the construction industry market. But the construction effect of the redispersible polymer powder is unsatisfactory due to the inappropriate selection. So it is very important to choose the right redispersible polymer powder, how to identify and select the redispersible polymer powder?
Method for identifying redispersible polymer powder
1. Mix redispersible polymer powder with water in a ratio of 1:5, stir evenly and let it stand for 5 minutes, then observe the sediment on the bottom layer. Generally, the less sediment, the better the quality of RDP.
2. Mix redispersible polymer powder with water in a ratio of 1:2, stir evenly, let stand for 2 minutes, and then stir evenly, pour the solution on a flat clean glass, place the glass in a ventilated shade, after fully drying, peel off the coating on the glass and observe the polymer film. The more transparent it is, the better the quality of redispersible polymer powder is. Pull the film moderately. The better the elasticity, the better the quality. Cut the film into strips. It was soaked in water, and observed after 1 day, the less dissolved, the better the quality.
3. Take an appropriate amount of polymer powder for weighing, put it in a metal container after weighing, heat it up to about 500℃, burn it at a high temperature of 500 ℃, and then weigh it after cooling. The lighter the weight, the better the quality.
4. Glue test with carton board or veneer. Take two small pieces of carton board or thin board of equal size, and apply glue to the interface of the sample. After 30 minutes of pressure on the object, take it out for inspection. If it can be firmly bonded and the interface is 100% destroyed, it is good quality of RDP. If the interface can only be partially destroyed, it means that the adhesive strength of RDP is not very good and the quality is unqualified. If the interface is intact and not damaged, it means that it is inferior and counterfeit.
Method for selecting redispersible polymer powder
1. The glass transition temperature (TG) of redispersible polymer powder. The glass transition temperature is an important indicator of the physical properties of RDP. For a specific product, a reasonable choice of the glass transition temperature (TG) of the RDP is beneficial to enhance the flexibility of the product and avoid problems such as cracking.
2. Minimum film forming temperature (MFFT). After redispersible polymer powder is mixed with water and re-emulsified, it has similar properties to the original emulsion, that is, a film will be formed after the water evaporates. The film has high flexibility and excellent adhesion to a variety of substrates.
The above is the method of identifying redispersible polymer powder and selecting redispersible polymer powder. People in the construction industry know RDP as Building Construction Chemicals importance. The quality of polymer powder is directly related to the quality and progress of construction. It is important to choose the suitable redispersible polymer powder.