Polyphosphoric acid (PPA), CAS 8017-16-1, is a viscous phosphorus-oxyacid consisting of linked phosphate units (variable polymerization). It is supplied commercially as a high-strength, non-volatile liquid reagent used primarily as a dehydrating agent and strong Brønsted acid catalyst in industrial organic synthesis and polymer manufacture. Typical industrial applications exploit PPA’s capacity to promote acylation, cyclisation, ring-closure and esterification reactions under anhydrous conditions, and to act as a condensation catalyst in specialty resin and polymer processes.
Applications & Descriptions
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Dehydration & Condensation Catalyst
Used to promote dehydration, condensation and acylation reactions (e.g., formation of anhydrides, imides and heterocycles) where a strong, non-nucleophilic acidic medium is required. -
Polymer & Resin Synthesis
Applied as a catalyst and dehydrating medium in the manufacture of specialty polyphosphoric esters, high-performance resins, polyimides and other condensation polymers. -
Cyclisation & Ring-Closure Chemistry
Employed to effect intramolecular cyclisations (e.g., heterocycle formation) that benefit from acid-promoted water elimination under controlled, anhydrous conditions. -
Esterification & Acylation Processes
Used to drive esterification and acylation where water removal and strong proton activity accelerate conversion and improve yields. -
Phosphorylation & Functional Group Installation
Utilised in selected phosphorylating or polyphosphorylating steps for specialty intermediates when a high-strength phosphorus oxyacid medium is required. -
Processing Aid for High-Temperature Condensations
Serves as a medium and catalyst for high-temperature condensations and for upgrading resins in dehydration steps. -
Laboratory Reagent & R&D Chemical
Supplied to research laboratories and pilot plants for method development, route scouting and small-scale synthesis requiring a robust dehydrating acid.
