Sodium Trimetaphosphate (STMP) Introduction
Sodium Trimetaphosphate (STMP) is an inorganic compound with the chemical formula Na₃P₃O₉, which belongs to condensed phosphate. It consists of three phosphate groups (PO₄) connected by oxygen atoms into a ring structure and has unique chemical and physical properties.
- Chemical properties：
- Molecular formula: Na₃P₃O₉
- Molecular weight: 305.88 g/mol
- Structure: cyclic, three PO₄ units connected by oxygen atoms.
- Solubility: easily soluble in water, the solution is alkaline.
- Stability: stable at room temperature, may hydrolyze to orthophosphate under high temperature or acidic conditions.
- Physical properties：
- Appearance: white crystals or powder.
- Melting point: about 628°C.
- Density: about 2.49 g/cm³.
- Preparation method：
- Thermal condensation method: heat sodium dihydrogen phosphate (NaH₂PO₄) to high temperature and remove water to generate sodium trimetaphosphate.
- Chemical synthesis method: generate by reacting phosphoric acid with sodium hydroxide under controlled conditions.
- Application Areas：
- Food industry: used as moisture retainer, thickener, stabilizer, used in meat products, dairy products, etc.
- Detergent: used as water softener and chelating agent to improve washing effect.
- Water treatment: used as scale inhibitor to prevent scale formation.
- Industrial field: used as dispersant and chelating agent in ceramics, textile and other industries.
- Safety and environmental impact：
- Safety: Generally considered safe, but high concentrations may irritate the skin and eyes.
- Environmental impact: Excessive discharge may cause eutrophication of water bodies, and use and discharge need to be controlled.
- Storage and transportation：
- Storage: Keep in a dry, ventilated place, avoid moisture and high temperature.
- Transportation: Treat as non-dangerous goods to prevent packaging damage.
Summary：
Sodium trimetaphosphate is an important chemical raw material, widely used in food, detergents, water treatment and other fields. Pay attention to safety and environmental protection when using it.