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Description and features

Catonium ETPAAC (Ethyltriphenylphosphonium Acetate) is a colourless to slightly yelow liquid, its chemical formula is C22H23O2P. ETPAAC is a quaternary phosphonium salt available in 70% by weight solution in methanol. One mole of acetic acid is bound to each mole of ETPAAC. The material is mainly used for the advancement and curing of phenolic based epoxy resins and as a phase transfer catalyst.

Ethyltriphnylphosphonium Acetate also known as ETPAAC, ETPAACc and TEPA.

Compared to amines, imidazoles and quaternary ammonium salts CatOnium ETPAAC features considerable better latency and thermal stability. Further it offers a low odor, minimal color formation and controlled reactivity.

It decreases or eliminates side reactions and creates longer, straighter chain epoxy molecules which have a sharp molecular weight distribution.

Shipment Info

Europe and United States: Provided CatOnium ETPAAC is on stock in our local warehouses our lead time is about one week if delivered in 200 KG drums.

Canada, South America, South Africa and other markets can also be served, please contact our sales department for more details.

➔ Limited available in the European Union as this product has not been REACH registered (yet).

Product Identification

CAS number35835-94-0
EC number 252-743-7
HS code2931 39 90


AppearanceColourless to slightly yellow liquid
Assay≥65 – 70 %
Cl≤0.50 %
Triphenyl phosphine ≤0.50 %


CatOnium ETPAAC (Ethyltriphenylphosphonium Acetate) is applied in the production of epoxy resins and as phase transfer catalyst.


Available packaging: 200 KG drums.
Special packaging is available on request.


Store Ethyltriphenylphosphonium Acetate in a cool, dry and well-ventilated area and in line with legal requirements.
Keep ETPAAC away from heat sources and oxidizing agents.


A Material Safety Data Sheets (MSDS) is available for CatOnium ETPAAC and all other products supplied by Vesta Chemicals bv.

An MSDS describes the hazards of a product and explains how a product can be safely handled, used and stored. Besides it provides important regulatory and emergency response information for the purchased product.

Molecular and structural information

Molecular formula C22H23O2P
Molecular weight 350.39 g/mol
Structural formula 35835-94-0 | Ethyltriphenylphosphonium Acetate

Physicochemical information

Boiling point 275 ºC @ 101 325 Pa
Relative density 1.19 @ 20 ºC
Flash point No data available
Melting point 79.8 ºC @ 101 325 Pa
Partition coefficient (log Pow) -0.64 @ 23.5 ºC
Solubility in water 938 g/L @ 20 ºC
Vapor pressure 1.08 exp-7 Pa at 25°C
Ethyltriphenylphosphonium Acetate | CAS: 35835-94-0 | Disclaimer. This information is supplied solely for informational purposes and Vesta Chemicals bv makes no guarantees or warranties, either expressed or implied, with respect to the accuracy and use of this data. All product warranties and guarantees shall be governed by the Standard Terms of Sale. Nothing in this document is legal advice or is a substitute for competent legal advice.