Ammonium Polyphosphate Flame Retardant Mechanism and advantage

Ammonium Polyphosphate Flame Retardant Mechanism and Advantage

Ammonium polyphosphate (APP) flame retardant can be classified into three types based on its degree of polymerization: low, medium, and high polymerization. The higher the polymerization degree, the lower the water solubility, and vice versa. Structurally, it can be divided into crystalline and amorphous forms, with crystalline APP being a long-chain water-insoluble salt. The general molecular formula of APP is (NH₄)ₙ₊₂PₙO₃ₙ₊₁. When n ranges from 10 to 20, it is water-soluble; when n exceeds 20, it becomes insoluble. APP is non-toxic, odorless, non-corrosive, and exhibits low hygroscopicity, high thermal stability, and excellent performance as a halogen-free flame retardant.

Flame Retardant Mechanism of APP:
When heated, APP decomposes to form poly-/metaphosphoric acid, which promotes dehydration and carbonization on the surface of organic materials. It expands upon heating, forming a protective layer that isolates the material from oxygen, thereby achieving flame retardancy. Additionally, the thermal decomposition of APP releases non-combustible gases such as CO₂ and NH₃, which dilute the oxygen concentration in the air, further cutting off the oxygen supply. These characteristics result in low smoke emission, no toxic gas production, and self-extinguishing properties. Notably, the absence of toxic gases is not only environmentally friendly but also critical for life safety—statistics show that over 80% of fatalities in major fire incidents are caused by toxic fumes from burning plastics, electronic components, and other materials, rather than the flames themselves.

Manufacturer of APP Flame Retardant:
Taifeng Flame Retardant uses internationally advanced multi-layer microencapsulation technology to produce high-polymerization-degree APP with high phosphorus and nitrogen content. The product features excellent thermal stability, low water solubility, near-neutral pH, and high flame-retardant efficiency. It is a white powdered solid, non-hygroscopic, non-flammable, and exhibits high molecular weight (n > 1200), stability, and weather resistance. It is widely used in water-based fireproof coatings, textile coatings, and as a key component in intumescent flame-retardant thermoplastics. The encapsulated product undergoes surface treatment for improved compatibility, enhanced moisture resistance, alkaline pH, and even lower water solubility.

More info., pls contact lucy@taifeng-fr.com