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White, microcrystalline, light weight powder

Phosphorus pentoxide (P2O5)

Phosphorus pentoxide is a white, microcrystalline, light weight powder which is produced by the combustion of elemental phosphorus in an excess of oxygen. Phosphorus pentoxide is the anhydride of orthophosphoric acid, H3PO4. It is very hygroscopic and is converted by water to H3PO4 via intermediates. The reaction with water is very vigorous and proceeds with the evolution of a large amount of heat.

Due to its highly hygroscopic and microcrystalline character, the capability of flowing of P2O5 may vary in a certain range. Furthermore, the formation of soft agglomerates, which come apart under slight pressure, is not preventable.

  • Wide variety of applications as a reagent in the chemical industry
For regulatory details such as the classification and labelling as dangerous substances or goods please refer to our corresponding Material Safety Data Sheet.
Characteristics Unit Target value DS¹) TD²) Test method
Appearance (at 20°C) white powder

Visual evaluation; (11/43
Phosphorus Pentoxide %(w/w) min. 99.5

Titration using alkaline; (11/11)
Lower Phosphorus Oxides (as P2O3) %(w/w) max. 0.02

Iodometry; 11/20)
Arsenic mg/kg max. 150

ICP - OES or AAS; (11/28 or 11/18)
Iron mg/kg max. 5

ICP - OES or photometry; (11/28 or 11/17)
Heavy Metals mg/kg max. 20

sulfide comparison acc. to DAB10; (11/05)
Bulk Density g/l approx. 500

¹) Delivery specification: The product is constantly monitored to ensure that it adheres to the specified values. Test methods: Clariant method numbers in brackets.
²) Technical data: The technical data are used solely to describe the product and are not subject to regular monitoring. For further information, please consult our standard delivery specification.
Phosphorus pentoxide is a useful building block and reagent in the chemical industry:

Organic synthesis
Phosphorus pentoxide can be used as a reagent for condensations in organic synthesis and polymerization reactions. Typical uses include cyclisation / ring closures in such reactions as acetylation, alkylation, production of amines, acid amides, cyclic ketones, cyclic olefins or oxygen and sulphur heterocyclic compounds. These types of reaction are widely used in the preparation of organic intermediates in the pharmaceutical, vitamin, colors and dyes industries.

Catalyst production
Phosphorus pentoxide can be used in the manufacture of special phosphoric acid supported catalysts.

Specialty inorganic phosphates
Phosphorus pentoxide can be used in the manufacture of specialty sodium and ammonium phosphates.

Polyphosphoric acids
Various grades of superphosphoric and polyphosphoric acids can be manufactured by blending phosphorus pentoxide with phosphoric acid.

Beside silicon dioxide and boron trioxide also phosphorus pentoxide is used for glass making.

Phosphate esters
Phosphorus pentoxide can be used to produce phosphate esters with a mono/di ester content. The acid is reacted directly with the appropriate alcohol or phenol to produce the acidic phosphate ester.

Drying agent
Because of its strong hygroscopic properties phosphorus pentoxide can be used as a drying agent.
Packaging and Handling
Delivery form

Phosphorus pentoxide is available in a wide variety of standard drums and containers:

50 kg net drum with or without PE-Inliner (450 kg net pallet)
180 kg net drum (720 kg net pallet)
1.375 kg Tote bin

Minimum shelf life is 12 months from the date of shipping when stored according to the said conditions.

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Phosphorus pentoxide (P2O5)

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