Sodium tripolyphosphate STPP

White powdery crystal with good fluidity, relative molecular mass of 367.86, melting point of 622°C, easily soluble in water, and its aqueous solution is alkaline. It is often used in food as a moisture retaining agent, quality improver, pH regulator, and metal chelating agent.

Detergent additive sodium tripolyphosphate is a detergent additive with excellent performance and the most commonly used component in the detergent production process. Its functions are in four aspects:
1. Chelation of heavy metal ions: During the washing process, heavy metal ions in the water can combine with detergent molecules to form insoluble metal salts, reducing the washing ability or even losing its effect completely. Therefore, it is necessary to add chelating agents to detergents that can turn heavy metal ions contained in the water into harmless substances. Sodium tripolyphosphate has a strong chelating effect on heavy metal ions, sealing them and eliminating their adverse effects on washing. In addition, it can capture various metal components contained in dirt and play a role in dissociating dirt during the washing process. It can be used as a soap synergist and prevent bar soap grease from settling and blooming.
2. Degumming, emulsifying and dispersing dirt: dirt often contains human body secretions (mainly proteins and fatty substances), as well as sand, dust, etc. from the outside world. Sodium tripolyphosphate has the effect of swelling and solubilizing the proteins in the dirt, thereby degumming; promoting the emulsification of fat; dispersing solid dirt; and having a strong emulsifying effect on lubricating oil and fat. Used to adjust the pH value of buffer soap.
3. Prevent caking of detergents: Powdered synthetic detergents are hygroscopic. If stored in a place with high humidity, caking will occur. Clumped detergent is extremely inconvenient to use. The hexahydrate formed by sodium tripolyphosphate after absorbing water has drying properties. When used in large quantities in detergent formulas, it can prevent clumping caused by moisture absorption and maintain the dry and granular shape of synthetic detergents.
4. It has a large alkaline buffering effect, keeping the pH value of the washing solution at around 9.4, which is beneficial to the removal of acidic dirt.
5. As an auxiliary, soap synergist and to prevent bar soap crystallization and frosting, industrial water softener, leather pretanning agent, dyeing auxiliary, oil well dredging control agent, oil pollution preventive agent for paper making, paint, kaolin It is an effective dispersant for the treatment of suspensions such as magnesium oxide and calcium carbonate.