IUPAC Name
Polyphosphoric Acid
Cas Number
8017-16-1
HS Code
2809.20.90
Formula
Hn+2PnO3n+1&
Industry
-
Appearance
Clear, Colorless, Viscous Liquid
Common Names
PPA, Phospholeum, Tetraphosphoric acid, Superphosphoric acid
Packaging
40 kg drum, 340 kg drum or 1600 kg IBC drum
Brief Overview
Polyphosphoric acid is a mixture of orthophosphoric acid and linear phosphoric acids. It is described empirically as a wt % of P2O5 in water. The distribution of phosphoric acids that are found in PPA is dependent upon the wt % of P2O5. Commercially available PPA contains 82-85% P2O5, with 83% P2O5 considered to be the standard. Polyphosphoric acid (PPA) is a thick, viscous liquid consisting of linear molecules of various chain lengths. The powerful dehydrating properties of PPA, low nucleophilicity of the phosphoric acid media, and moderate acidity makes this reagent very widely used.
Manufacturing Process
Polyphosphoric acid is produced by condensation polymerization of ortho-phosphoric acid as follows:
2 H3PO4 → H4P2O7 + H2O
Dehydrating Agent
Polyphosphoric acid is used as a strong drying and dehydrating agent.
Organic Synthesis
Polyphosphoric acid is used to make phosphate esters, acid phosphates and pharmaceuticals. It is a good ring closing reagent.
Solvent
It can be used as a reaction medium and solvent.
Others
It is used in metal treatment and as an asphalt and bitumen additive.
