Ammonium polyphosphate (APP) is an inorganic phosphorus compound, widely used as a flame retardant, fertilizer and food additive. The following is a detailed introduction to APP:
Basic Information：
- Chemical formula: (NH₄PO₃)ₙ
- Molecular weight: Uncertain (depending on the degree of polymerization n)
- CAS number: 68333-79-9
Physical properties:
- Appearance: white powder or granules
- Density: about 1.9 g/cm³
- Melting point: about 300°C (decomposition)
- Solubility:
Slightly soluble in water, solubility decreases with increasing degree of polymerization
Insoluble in organic solvents
Chemical properties:
- Stability: Stable at room temperature, but may decompose at high temperature or under strong acid/base conditions.
- Reactivity:
Can react with strong oxidants.
Easily absorbs moisture in the air and needs to be stored in a sealed container.
Main Applications:
- Flame retardant:
Used in plastics, rubber, coatings and textiles to improve the flame retardant properties of materials.
Commonly found in materials such as polypropylene (PP), polyethylene (PE) and polyurethane (PU). - Fertilizer:
As a slow-release fertilizer, it provides phosphorus and nitrogen elements required by plants. - Food additive:
Used in food processing as a leavening agent and acidity regulator. - Other applications:
Used in fire-retardant coatings, wood treatment and paper flame retardant.
Safety and Environmental Protection:
- Toxicity: Low toxicity, but long-term contact may be irritating to the skin and eyes. Animal experiments show that high doses may have effects on the respiratory system.
- Environmental impact: Not easily biodegradable and may accumulate in water and soil. Care should be taken to prevent leakage and environmental pollution.
Storage and transportation:
- Storage:
Store in a cool, dry, well-ventilated place, away from fire and oxidants.
Avoid high temperature and humidity. - Transportation:
Transport as general chemicals, avoid severe vibration and high temperature.
Regulations:
- International regulations:
It is necessary to comply with the regulations of various countries regarding the use and discharge of chemicals, such as REACH, RoHS, etc.
Pros and Cons:
- Pros:
Excellent flame retardant and fertilizer capabilities.
Chemically stable and versatile. - Cons:
Potential environmental and health hazards.
Could be replaced by greener options in some uses.
Ammonium polyphosphate plays an important role in industrial and commercial applications, but its use needs to pay attention to safety and environmental issues, especially in areas where it needs to come into contact with the human body or the environment.