Ammonium Polyphosphate Phase II (APP)

Manufacturer & Exporters of Ammonium Polyphosphate Phase II (APP) in China


Ammonium polyphosphate Phase II tb chemical

Fine, free flow white powder

Ammonium polyphosphate Phase II TB Chemical
Ammonium polyphosphate Phase II TB Chemical -02

2. Physical And Chemical Properties

Chemical Name :Ammonium polyphosphate
Empirical Formula:(NH4PO3)n
CAS No.:68333-79-9
Molecular Weight:Varying, 97(number average)
Structural Formula:

Ammonium polyphosphate Phase II Physical And Chemical Properties

Melting point:> 300°C (dec.)
Relative density:1.8 -2.0 g /cm 3 ( 25°C )
Solubility:in water <0. 8 g /100ml( 25°C )
Acute oral LD50:>5000mg/kg (rat)

3.Index Content

Phosphorus content of 31.0 ~ 32.0% Density g / cm3 = 1.9
Nitrogen content of 14.0 to 15.0% Bulk density g / ml = 0.7
Pentoxide content of 71.0 ~ 73.3% Polymerization degree ≥1000
Initial decomposition temperature ℃> 260
PH value (25 ℃, 10% suspension) 5.5 to 7.5
Water Solubility% <0.5 Viscosity (25 ℃, 10% suspension) ≤100
The average particle diameter μm 3.0 ~ 5.0
Water content% <0.5
Toxicity and environmental dangers of undetected

4. Application

(1)  Ammonium polyphosphate(APP) is used as a food additive, emulsifier and as a fertilizer.

(2)  Ammonium polyphosphate (APP) is also used as a flame retardant in many applications such as paints and coatings, and in a variety of polymers: the most important ones are polyolefins, and particularly polypropylene, where APP is part of intumescent systems.Compounding with APP-based flame retardants in polypropylene is described in.Further applications are thermosets, where APP is used in unsaturated polyesters and gel coats (APP blends with synergists), epoxies and polyurethane castings (intumescent systems). APP is also applied to flame retard polyurethane foams.Ammonium polyphosphates as used as flame retardants in polymers have long chains and a specific crystallinity (Form II). They start to decompose at 240 °C to form ammonia and phosphoric acid. The phosphoric acid acts as an acid catalyst in the dehydration of carbon-based poly-alcohols, such as cellulose in wood. The phosphoric acid reacts with alcohol groups to form heat-unstable phosphate esters. The esters decompose to release carbon dioxide and regenerate the phosphoric acid catalyst. In the gas phase, the release of non-flammable carbon dioxide helps to dilute the oxygen of the air and flammable decomposition products of the material that is burning. In the condensed phase, the resultant carbonaceous char helps to shield the underlying polymer from attack by oxygen and radiant heat. Use as an intumescent is achieved when combined with starch-based materials such as pentaerythritol and melamine as expanding agents. The mechanisms of intumescence and the mode of action of APP are described in a series of publications.