Flame Retardants
Flame Retardant APP
Ammonium Polyphosphate (Phase II)
Halogen-free intumescent workhorse — n>1000 APP for coatings, foams and polyolefins.
Product Description
Ammonium polyphosphate (phase II, high polymerization degree) is the foundation of intumescent flame retardant technology. When heated above 250 °C it releases phosphoric acid and ammonia, catalyzing char formation together with carbon sources such as pentaerythritol and blowing agents — building an insulating foam barrier that starves the flame.
Aolong APP-1000 grade (n > 1000, water solubility < 0.5 g/100 mL) provides the water resistance demanded by exterior intumescent coatings and construction profiles. Standard APP-300 grades serve cost-sensitive polyurethane foam and adhesive applications.
In polypropylene, APP-based intumescent systems achieve UL 94 V-0 at 25–30% total loading; in steel-structure coatings they provide the fire-protection layer certified under GB and EN fire codes. Micronized (D50 ≈ 2 μm) surface-treated grades are available for thin-film and transparent applications.
Key Features
- Halogen-free, low-smoke intumescent mechanism
- n > 1000 grade with water solubility < 0.5 g/100 mL
- Micronized and surface-treated grades available
- Effective in coatings, PU foam and polyolefins
Applications
- Intumescent coatings for steel structures
- Rigid and flexible polyurethane foams
- Polypropylene intumescent FR compounds
- Elastomers, epoxies and rubbers
- Sealants and adhesives
Specifications
| CAS No. | 68333-79-9 |
|---|---|
| Molecular Formula | (NH4PO3)n |
| Molecular Weight | 97.09 (per unit) |
| Appearance | White fine powder |
| P2O5 Content | ≥ 71% |
| N Content | 14 – 15% |
| Polymerization Degree | ≥ 1000 |
| Water Solubility (25 °C) | ≤ 0.5 g / 100 mL |
Packaging & Storage
25 kg woven PP bag with PE liner, 500 kg or 1,000 kg jumbo bag. Store cool and dry; shelf life 24 months in original sealed packaging.
Related Products
Need a custom additive solution?
Send us your technical requirements — our engineers will reply with product recommendations, TDS documents and a competitive quotation within 24 hours.