Ammonium Polyphosphate (APP): Advanced Flame Retardant Solution

Ammonium Polyphosphate (APP) is a highly effective intumescent flame retardant widely used across multiple industries to enhance fire safety in materials and products.

As an inorganic compound with the chemical formula (NH₄PO₃)ₙ, APP represents a critical component in modern fire protection technology.

What is APP?

APP is a white, crystalline powder that belongs to the polyphosphate family. It exists in two primary forms: Form I (crystalline) and Form II (amorphous), each offering distinct properties suited for different applications. The material is characterized by its excellent thermal stability, low water solubility, and exceptional flame retardant performance.

Key Properties

The compound’s effectiveness stems from its unique intumescent behavior. When exposed to high temperatures, APP undergoes a chemical reaction that creates an expanded char layer, which acts as an insulating barrier between the heat source and the underlying material. This protective layer significantly slows combustion and prevents flame spread.

Applications

APP finds extensive use in coatings, plastics, textiles, and building materials. It’s particularly valued in intumescent paints and coatings for structural steel protection, as well as in polymer applications including polyolefins, polyurethanes, and epoxy resins. The textile industry employs APP in flame-retardant fabrics, while the construction sector utilizes it in fireproofing materials and sealants.

Advantages

Compared to halogenated flame retardants, APP offers significant environmental and safety benefits. It releases no toxic gases during combustion, produces minimal smoke, and is non-corrosive. These characteristics make it increasingly preferred in applications where human safety and environmental compliance are paramount.

Product Name	Ammonium Polyphosphate
Chemical Formula	(NH₄)ₙ₊₂PₙO₃ₙ₊₁
CAS Number	68333-79-9
Packaging	25 kg bags or jumbo bags