HEDP (1-Hydroxyethylidene-1,1-Diphosphonic Acid) corrosion inhibitors generally exhibit good thermal stability and can withstand high temperatures to a certain extent. However, their performance and stability may vary depending on factors such as concentration, pH, duration of exposure, and specific application conditions.
In general, HEDP is stable and effective in temperatures up to around 150-200°C (302-392°F). At higher temperatures, the degradation rate of HEDP may increase, and its effectiveness as a corrosion inhibitor can diminish. The exact temperature threshold for HEDP’s stability can depend on the specific formulation, purity, and other factors.
It’s worth noting that HEDP can undergo thermal decomposition at elevated temperatures, resulting in the release of phosphorous-containing gases. This decomposition process can be influenced by factors such as acidity, presence of metal ions, and oxygen availability. It is crucial to consider these factors when using HEDP at high temperatures to ensure its continued effectiveness and safe operation.
More information about HEDP is as follows:
HEDP is an organophosphoric acid corrosion inhibitor. It can chelate with Fe, Cu, and Zn ions to form stable chelating compounds.It can dissolve the oxidized materials on these metals’ surfaces.HEDP shows excellent scale and corrosion inhibition effects under temperature 250℃. HEDP has good chemical stability under high pH value, hard to be hydrolyzed, and hard to be decomposed under ordinary light and heat conditions. Its acid/alkali and chlorine oxidation tolerance are better than that of other organophosphoric acids (salt).HEDP can react with metal ions in water system to form hexa-element chelating complex, with calcium ion in particular. Therefore,HEDP has good antiscale and visible threshold effects. When built together with other water treatment chemicals, it shows good synergistic effects.
The solid state ofHEDP is crystal powder, suitable for usage in winter and freezing districts. Because of its high purity, it can be used as cleaning agent in electronic fields and as additives in daily chemicals.