Ethylene diamine tetra methylene phosphonic acid sodium, also known as
EDTMPS, is a nitrogen - containing organic polyphosphonic acid. Here is a detailed account
Basic Information
CAS No.：1429 - 50 - 1 (Some sources also list 22036 - 77 - 7)
Molecular Formula：C6H12O12N2P4Na8
Molecular Weight：612.13.
Properties
Solubility：It is highly soluble in water, capable of forming stable aqueous solutions.
Chemical Stability and Thermal Tolerance：It has good chemical stability and thermal tolerance, showing excellent scale inhibition ability at 200 ℃.
Corrosion Inhibition：It is a cathodic corrosion
inhibitor, and its corrosion inhibition performance is 3 - 5 times
better than that of inorganic polyphosphates.
Chelation：In aqueous solution, it can dissociate
into eight positive - negative ions, which can chelate with many metal
ions to form a polymer reticulation complex, thus destroying the normal
crystallization of calcium scale and showing good antiscale effects on
calcium sulfate and barium sulfate.
Applications
Water Treatment：It is used as a corrosion and scale inhibitor in circulating cooling water systems and boiler water.
Electroplating Industry：It serves as a chelating agent in the non - cyanogen electroplating industry.
Textile and Dyeing Industry：It functions as a water - softening agent and oxygen bleaching stabilizer in the textile printing and dyeing industry.
Specification
Appearance：It usually appears as a clear yellow to umber transparent liquid.
Active Component：The active component (EDTMPS) is at least 30.0%. Other components include organic phosphonic acid (as PO43−) at least 10.0%, phosphorous acid (as PO33−) at most 3.0%, phosphoric acid (as PO43−)
at most 1.0%, chloride ($Cl^ - $) at most 2.0%, and the pH of a 1%
water solution is 9.5 - 10.5. The density at 20 ℃ is at least 1.25
g/cm³.
Packaging and Storage：It is typically packaged in
200L plastic drums or 1000L IBCs, and should be stored in a shady and
dry place for up to ten months.
