Sodium Tripolyphosphate (STPP)

Sodium triphosphate (STP), also sodium tripolyphosphate (STPP), or tripolyphosphate (TPP), is an inorganic compound with formula Na5P3O10. It is the sodium salt of the polyphosphate penta-anion, which is the conjugate base of triphosphoric acid. It is produced on a large scale as a component of many domestic and industrial products, especially detergents. Environmental problems associated with eutrophication are attributed to its widespread use.

STPP is a colourless salt, which exists both in anhydrous form and as the hexahydrate. The anion can be described as the pentanionic chain [O3POP(O)2OPO3]5. The use of sodium tripolyphosphate has many advantages, it can effectively increase the strength, toughness and durability of cement concrete, and prolong its service life. In addition, sodium tripolyphosphate can also increase the fluidity of the slurry and reduce the mixing time, thereby significantly improving the construction efficiency. Therefore, the application of sodium tripolyphosphate can effectively improve the quality, speed and economy of engineering construction. However, there are also certain risks associated with the use of sodium tripolyphosphate, such as excessive use will cause cement concrete structures to collapse, and the hydration reaction will be too rapid to affect the strength. Therefore, it is necessary to be cautious when using sodium tripolyphosphate, with appropriate technical parameters, and the dosage should not be too large.