Appearance: olorless viscous liquid, easy to deliquesce.
Formular: H n +2 P n O 3n+1
Melting point: 16 ~ 30 ℃
Boiling point: 856 ℃
Relative density (water = 1): 2.1
Solubility: miscible with water
Polyphosphoric acid (PPA) has strong dehydration, low nucleophilicity and moderate acidity. Unlike sulfonic acid, polyphosphoric acid generally does not oxidize the reactants and is soluble in organic solvents. Although its acidity is weaker than sulfonic acid, its dehydration is equivalent to 100% sulfonic acid, so it is widely used in laboratories. .