Ammonium Polyphosphate

Origin
China
CAS Number
68333-79-9
HS Code
2835.39.00

Basic Info

IUPAC Name
ammonium polyphosphate
Molecular Formula
(NH4PO3)n
Synonyms & Trade Names
Ammonium polyphosphate; APP; FR-CROS
Purity / Assay (%)
67% P2O5 min
Physical Form
Solid
Concentration
Pure substance
Appearance / Color
White to off-white solid
Odor
Odorless
Density (g/cm³)
1.6000
Solubility in Water
Soluble in water
UN Number
Not applicable
H-Statements
None
P-Statements
P260
REACH Status
Registered
Drug Precursor Status
Non-precursor
Storage Class (GHS)
13
Storage Conditions
Cool, dry place; avoid moisture

Categories

Technical Document

Brief Overview
Ammonium Polyphosphate (APP) is a fully water-soluble phosphate widely employed in plant applications. It is an ammonia and polyphosphoric acid-derived inorganic salt with a variable and branched chain length. Short-chain APP is more water-sensitive and less stable than longer-chain varieties. Two primary types exist: Crystal Phase 1 APP with a linear structure and Crystal Phase 11 APP with a branched structure. APP is environmentally safe and non-toxic, finding use as a flame retardant that, due to its distinctive intumescence mechanism, does not produce smoke.
Manufacturing Process
APP is produced through the reaction of concentrated phosphoric acid with ammonia. However, impurities containing iron and aluminum dissolve in concentrated phosphoric acid, leading to the formation of gelatinous precipitates in APP. In industrial settings, APP is synthesized through polycondensation involving monoammonium phosphate and urea.