Ammonium polyphosphate

• CAS: 68333-79-9
• Catalog Number: ALC-FP-68333799
• Category: Featured Products
• Appearance: White powder
• Content: P2O5≥ 45%; N≥ 25%
• pH: 6.0 - 8.5
• Polymerization Degree: < 20
• Sample Lot No.: A24Q1704
• Solubility In Water: > 45 g (25 °C 100 mL H2O)

Case Study

Ammonium Polyphosphate for the Fabrication and Fire Protection Application of Silica Gel Foam

Du W, et al. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2026, 729, 138951.

Ammonium polyphosphate (APP) was experimentally applied as a functional additive in silica gel foam to enhance fire prevention and extinguishing performance on wood substrates. Silica gel foam containing APP was prepared via a hydrolysis-condensation process of sodium silicate combined with mechanical foaming. Sodium dodecyl sulfate and sodium carboxymethyl cellulose were introduced as foaming agent and stabilizer to construct a stable foam-gel system. APP and acetic acid were subsequently added to induce silicic acid formation and Si-O-Si network condensation, allowing APP to be uniformly embedded within the inorganic matrix. The optimized formulation containing 10 wt% APP exhibited suitable gelation time and viscosity, enabling uniform coating on wood. Fire tests confirmed that the APP-containing foam significantly reduced heat release, smoke generation, and ignition susceptibility through combined physical insulation and condensed-phase flame-retardant effects.

Ammonium Polyphosphate as a Flame-Retardant Electrolyte Additive for High-Nickel Lithium-Ion Batteries

Zhang F, et al. iScience, 2025, 28(12), 114117.

Ammonium polyphosphate was investigated as a flame-retardant additive in liquid electrolytes for high-nickel LiNi₀.₉Co₀.₀₅Mn₀.₀₅O₂/graphite-Si pouch cells. APP was directly dissolved into the electrolyte at controlled concentrations (5-10 wt%) and assembled into 1 Ah pouch cells using standard battery fabrication procedures. Electrochemical cycling and thermal abuse tests were conducted to evaluate performance and safety. Cells containing APP demonstrated effective suppression of ignition under elevated temperatures while maintaining high capacity retention during long-term cycling. Interface analysis indicated that APP participation led to thicker electrode interphases, accounting for minor capacity loss. The experimental results validate APP as a practical electrolyte-level fire-retardant additive that enhances thermal safety without severely compromising battery performance.

Ammonium Polyphosphate for Explosion Suppression Using Modified Gel Dry Water

Du Y, et al. Fuel, 2026, 410, 137938.

Ammonium polyphosphate was experimentally applied to modify gel dry water (AGDW) for suppressing ammonia-hydrogen-air explosions. AGDW was prepared by dispersing APP powder in deionized water, followed by the addition of superabsorbent polymer to form an APP gel. Hydrophobic nano-silica was subsequently incorporated under high-speed shear to encapsulate the gel into dry water particles. The suppressant was introduced into a transparent horizontal pipeline containing premixed NH₃-H₂-air mixtures. Explosion suppression performance was evaluated by measuring flame temperature, pressure, and propagation behavior. AGDW significantly reduced peak temperature and explosion pressure, achieving complete flame quenching. The effectiveness was attributed to APP-derived phosphorus radicals chemically scavenging reactive species during combustion, demonstrating a combined physical-chemical suppression mechanism.