HEDP Na2 is organic phosphonic acid corrosion inhibitor. It has two appearances, colourless to pale yellow transparent liquid and white powder. White powder HEDP Na2 (Etidronate Disodium), its melting point is 198°C – 199°C. It is soluble in water and ethanol and has strong moisture absorption.
CAS No.7414 83 7
Molecular Formula: C2H8O7P2Na2
Molecular Weight: 250
HEDP 2Na, disodium salt of 1-hydroxy ethylidene-1 1-diphosphonic acid, HEDP Na2
Etidronate Disodium, HEDP Na2
HEDP Na2 has good scale and corrosion inhibition effects even under 250℃. It can dissolve the oxidized materials. HEDP Na2 is stable at high pH value. It is not easy to be hydrolyzed and to be decomposed under normal light and heat condition. HEDP Na2 acid/alkaline and chloride oxidation tolerance are better than that of other organic phosphonic acids.
HEDP Na2 can form six-ring chelating compounds with metal ions in a water system, Ca2+ in particular. This product also has good obvious dissolution threshold effects. When used with other water treatment agents, its synergistic effects are better.
HEDP Na2 is known in the market as an organo-phosphonic acid corrosion inhibitor. HEDP Na2 can chelate with Fe, Cu, and Zn ions. HEDP Na2 (Etidronate Disodium) with chelation value 270 is a good substitute for EDTA disodium powder.
|Appearance||colourless to yellowish transparent liquid||white powder|
|Active content (HEDP) %||≥ 16.5||74.0 – 79.0|
|Active content (HEDP Na2) %||≥ 20||≥ 89.8|
|Phosphoric acid (as PO33- )%||—||≤ 3|
|Dry weight loss %||—||3 – 6|
|pH (1% solution)||4.0 – 6.0||4.0 – 6.0|
|Density (20℃) g/cm3||1.12-1.22||—|
|Moisture %||—||3.0 – 6.0|
Used as corrosion inhibitor & chelating agent in circulating cool water system
Used as corrosion inhibitor medium and low-pressure boiler
Used as corrosion inhibitor oil field water pipelines
Used as detergent for metal and nonmetal in light woven industry
Used as peroxide stabilizer and dye-fixing agent in dyeing industry
Used as chelating agent in non-cyanide electroplating