Sodium Tripolyphosphate Used As Detergent Auxiliary

Sodium tripolyphosphate is white powder or powder with an apparent density of 0.35-0.90g/cm3 and a melting point of 622 degrees Celsius. It is easily soluble in water, the aqueous solution is alkaline, and the pH of 1% aqueous solution is 9.7. It is gradually hydrolyzed into phosphite in water and has a good ability to complex metal ions. It can complex with calcium, magnesium, iron and other metal ions to form soluble complexes and soften hard water. As an inorganic surfactant, it has the properties of a certain organic surfactant. With these properties, Chemate stpp uses in detergent has good performance.

Uses of Sodium Tripolyphosphate in Industrial Fields

It is mainly used in synthetic detergents as additives, soap synergists and to prevent the precipitation and blooming of bar soap grease. It has a strong emulsification effect on lubricating oil and fat. It can be used to adjust the pH value of buffer soap, water softener for industrial water, leather pretanning agent, dyeing auxiliary, paint, kaolin, magnesium oxide, calcium carbonate and other industries. Used as a dispersant when preparing suspensions, as a dispersant for drilling mud, and as an anti-greasy agent in the paper industry.

The Role of STPP in Detergents

Sodium tripolyphosphate is an indispensable and excellent auxiliary in detergents. The content of most detergents is 10-50%. Its main functions can be summarized as follows.

1. Chelation of metal ions. Daily washing water generally contains hardening metal ions (mainly Ca2+, Mg2+). During the washing process, they will form insoluble metal salts with the active substances in the soap or detergent, so that not only the consumption of the detergent is increased, but also the fabric after washing has an unpleasant dark gray. Sodium tripolyphosphate has excellent properties of chelating hard metal ions, thereby eliminating the adverse effects of these metal ions.
2. Improve peptization, emulsification and dispersion. Dirt often contains human secretions (mainly proteins and fats), as well as sand and dust from the outside world. Sodium tripolyphosphate has the effect of swelling and solubilizing protein to peptize; it can promote the emulsification of fatty substances; it can disperse and suspend solid particles.

3. Buffer effect. Sodium tripolyphosphate has a large alkaline buffering effect, keeping the pH value of the washing solution at about 9.4, which is beneficial to the removal of acid dirt.

4. Prevent caking. Powdery synthetic detergent has hygroscopicity, if stored in a place with high humidity, it will cause agglomeration. The use of agglomerated detergent is extremely inconvenient. The hexahydrate formed by sodium tripolyphosphate has dry properties. When there is a large amount of sodium tripolyphosphate in the detergent formula, it can prevent the agglomeration caused by moisture absorption and keep the dry granular synthetic detergent.

The Environmental Impact of Phosphorous Detergents

STPP also has its inevitable environmental hazards. Due to its phosphorus content, it is easy to cause water eutrophication. Sodium tripolyphosphate will be hydrolyzed in water to produce tripolyphosphoric acid. This is a weak acid with a weak degree of hydrolysis and will not acidify the water. Phosphorus-containing substances will be absorbed by the algae in the water and cause mass reproduction. Under the circumstance, only respiration consumes oxygen, causing aquatic organisms to die of hypoxia, causing water pollution.

Chemate, as a professional manufacturer, can supply various phosphorus chemicals, such as, phosphoric acid, sodium tripolyphosphate stpp, sodium hexametaphosphate shmp, etc.