what is redispersible polymer powders?
Redispersible Polymer Powder (RDP) is spray dried redispersible polymer powder,also named as Redispersible emulsion Powder or latex powder ,produced by spray-drying special water-based emulsion, mostly based on vinyl acetate-ethylene (RDP/VAE),then obtained a free flowing organic polymer powder. It can re-disperse in water, and form a film after water evaporation by coalescence of individual polymer particles. The film acts as an organic binder, to glue together different substrates, reinforce mortar structure and provide excellent adhesion at cement or gypsum based dry mixed mortar substrate interface.
Redispersible Polymer powder (Redispersible Latex powder) is the main raw material in production of internal, external wall putty, adhesive mortar and plaster mortar. the powder is specially applied as the agglutinant of basis materials on triple superphosphate, Talcum powder and white cement and so on. It can improve the adhesion properties water resistance, flexural strength and operability of the basis materials.
Adding redispersible polymer powder into the mortar can improve the binder, binder and flexibility of the mortar.First, it can improve the water retention performance of mortar
And forms a film to reduce evaporation of water.Secondly, the bond strength of mortar can be improved.
In 1953, German Wacker Hemie invented redispersible polymer powder, which made the production of polymer modified dry powder mortar possible.The history of the
So far, redispersible polymer powders have only been studied for more than 50 years.In 1953, Germany invented the world's first practical redispersible powder.With the continuous
Continuous innovation and progress in the production process of follow-up products have made a series of achievements and developed a series of products in combination with it
Subsequent applications.
The world's first redispersible polymer powder is vinyl acetate homomer powder.But the polymer powder can only be used in non-alkaline systems because
Esters or polymers with ester bonds react under alkaline conditions to form free alcohols or acidates, resulting in sudden changes in properties from non-aqueous
It is soluble in water and thinks that the increase of glass transition temperature will lose the required elasticity, or for other reasons.In 1960, vinyl
Acetate copolymer (EVA) powder was prepared successfully. The internal plasticization of the redispersible material was mainly conducted by using unsaponifiable organic monomer ethylene
It can also improve the flexibility of polymer powder.The polymer powder can be used in alkaline system of Portland cement.
Redispersible Polymer powder - specification
|
Appearance |
white powder, free-flowing |
|
Solid content |
≥98.0% |
|
Ash content (1000℃) |
12%±2 |
|
Bulk density |
400−550 g/l |
|
Average particle size |
~80 μm |
|
PH value |
5.0-8.0 |
|
TG(Glass Transition Temperature) |
16℃ |
|
Minimum film-forming temperature(MFFT) |
0°C |
Characteristic
1,Comprehensively improve wall putty adhesion, flexibility
2,Increased adhesion to a variety substrates
3,Dissolves in water easily and forms emulsion quickly
4,Improve the compressive strength of the mortar, prevent craking
