Ammonium polyphosphate 68333-79-9

What is Ammonium Polyphosphate?

Ammonium polyphosphate , also known as ammonium polyphosphate , is a type of inorganic polymeric phosphate composed of ammonium ions and polyphosphate groups. It is typically produced by polycondensation reactions of phosphoric acid, ammonia, urea, or other phosphate raw materials.

Its general formula can often be expressed as:

H12N3O4P

in:

· NH4+ and NH4 + represent ammonium ions;

· PO3−PO3− represents a polyphosphate repeating unit;

· nn represents the degree of aggregation.

Judging from the English name:

· Ammonium represents ammonium;

· Polyphosphate stands for polyphosphate salt;

· Ammonium polyphosphate is also known as ammonium polyphosphate.

· It is commonly abbreviated as APP .

In simple terms, Ammonium Polyphosphate is a phosphorus- and nitrogen-containing inorganic polymeric flame retardant . When heated, it promotes the dehydration and char formation of materials, releasing non-flammable gases and helping to form an expanded char layer, thereby isolating heat and oxygen to achieve a flame-retardant effect.

Industrial-grade ammonium polyphosphate typically has the following characteristics:

· White powder or granules ;

· Contains phosphorus and nitrogen ;

· Halogen-free flame retardant ;

· Low smoke and low toxicity tendencies ;

· It has good thermal stability ;

· Suitable for intumescent flame retardant systems ;

· It can promote the carbonization of materials ;

· It can be used in synergistic effects with pentaerythritol, melamine, etc.

· It can be used in plastics, rubber, coatings, textiles, wood, and composite materials ;

· Industrial-grade products cannot be used in food, medicine, or human ingestion scenarios .

What are the main uses of industrial-grade Ammonium Polyphosphate?

1. Used as a halogen-free flame retardant

Ammonium polyphosphate is a typical halogen-free phosphorus-nitrogen flame retardant.

Main function:

· Improve the flame retardancy rating of materials;

· Reduce the combustion rate;

· Reduce the spread of the fire;

· Reduce the rate of heat release;

· Reduce smoke and corrosive gases;

· Replaces some halogenated flame retardants;

· It aligns with the trend of halogen-free and environmentally friendly practices.

Possible applications:

· Polyolefin plastics;

· Engineering plastics;

· rubber;

· Thermoplastic elastomers;

· coating;

· Composite materials;

· Materials for wires and cables.

2. Used in intumescent fire-retardant coatings

APP is the core acid source in intumescent fire retardant coatings.

Main function:

· When heated, it produces acidic substances;

· Promotes the dehydration and carbonization of the char-forming agent;

· In conjunction with the gas source, an expanded carbon layer is formed;

· Improve the fire resistance time of the coating;

· Protect steel and wood structures;

· Reduce the heating rate of the substrate.

Common compound systems:

· APP + pentaerythritol + melamine;

· APP + starch-based charring agent + foaming agent;

· APP + acrylic emulsion;

· APP + epoxy resin;

· APP + polyurethane system.

Possible applications:

· Fireproof coating for steel structures;

· Fire-retardant coatings for wood;

· Fire-retardant coating for cables;

· Tunnel fireproof coating;

· Fire-resistant coatings for buildings.

3. Used in flame-retardant plastics and flame-retardant masterbatches

APP can be used as an important raw material for flame retardant modification of plastics, especially suitable for halogen-free flame retardant systems.

Main function:

· Improve the oxygen index of plastics;

· Improve vertical combustion rating;

· Reduce the risk of dripping combustion;

· Promotes carbonization of material surface;

· Reduce combustion smoke;

· Synergistic with char-forming agents and nitrogen-based flame retardants.

Possible applications:

· PP flame retardant material;

· PE flame retardant material;

· TPU flame retardant material;

· Flame retardant modification of PA;

· TPE flame retardant material;

· Polyurethane foam;

· Flame retardant masterbatch.

It should be noted that ordinary APP has limited compatibility and water resistance in plastics, and coated APP or surface-treated APP is often used in engineering plastics.

4. Used for flame retardant treatment of wood and wood-based materials.

The APP can be used in wood fire retardants, impregnated flame retardants, or flame retardant systems for wood-based panels.

Main function:

· Promotes the dehydration and carbonization of wood;

· Reduce the rate of flame spread;

· Reduce open flame combustion;

· Improve the flame retardancy rating of wood;

· Improve the fire resistance of wood structures;

· Suitable for fire protection of building and decorative materials.

Possible applications:

· Flame-retardant plywood;

· Flame-retardant MDF;

· Timber structure building;

· Decorative panels;

· Exhibition boards;

· furniture materials;

· Fire door core material.

5. Used for flame-retardant finishing of textiles

APP can be used in flame-retardant finishing systems for fibers and fabrics, and is especially suitable for compounding with resins, crosslinking agents or other phosphorus and nitrogen flame retardants.

Main function:

· Reduce the flammability of fabrics;

· Reduce the spread of the fire;

· Promote fiber carbonization;

· Improve flame retardant durability;

· Applicable to safety requirements for textiles in public places.

Possible applications:

· curtain;

· carpet;

· Sofa fabric;

· Stage curtain;

· Vehicle interior;

· Protective clothing;

· Industrial fabrics.

6. Used for fireproofing and sealing materials

The APP can be used in fireproof sealants, fireproof putty, fireproof bags, and fireproof sealing systems.

Main function:

· Expansion due to heat;

· Forming a heat-insulating carbon layer;

· Block the flame and smoke passages;

· Delay the spread of the fire;

· Protect cables, pipes, and building gaps;

· Improve the safety of fire compartments in buildings.

Possible applications:

· Fireproof sealing of cables passing through walls;

· Fireproof sealing of pipe penetrations;

· Sealing of building joints;

· Fireproof sealant;

· Fireproof bag;

· Fireproof boards.

Summarize

Ammonium polyphosphate , abbreviated as APP , is an inorganic polyphosphate containing phosphorus and nitrogen. Its common general formula is:

H12N3O4P

Industrial-grade ammonium polyphosphate is an important raw material in modern halogen-free flame retardant systems, mainly used for:

· Halogen-free flame retardant;

· Intumescent fire-retardant coatings;

· Flame-retardant plastics and flame-retardant masterbatches;

· Flame retardant treatment for wood and wood materials;

· Flame-retardant finishing for textiles;

· Fireproof sealing and sealing materials;

· Flame retardant modification of rubber, foam and composite materials.

In our daily lives, we may indirectly come into contact with Ammonium Polyphosphate through the following products:

· Fire-retardant coatings and fire-retardant coatings;

· Flame-retardant plastic products;

· Wires, cables and electrical materials;

· Fire-retardant treatment products for wood and wood-based panels;

· Flame-retardant textiles and decorative materials;

· Rubber, foam, and sealing materials;

· Fireproof building materials.

Finally, it must be emphasized that industrial-grade ammonium polyphosphate should not be used in food, beverages, pharmaceuticals, health products, animal feed, or any other application involving human or animal ingestion. In practical industrial applications, key considerations should be given to degree of polymerization, phosphorus and nitrogen content, water solubility, thermal stability, particle size, surface treatment, dispersibility, water resistance, flame retardancy, material compatibility, and moisture protection during storage.