2-Phosphonobutane-1,2,4-tricarboxylic acid (PBTC) | CAS: 37971-36-1
2-Phosphonobutane-1,2,4-tricarboxylic acid (PBTC) is a high-efficiency, environmentally friendly and internationally upgraded phosphine carboxylic acid water treatment chemical. As a mainstream and high-performance scale and corrosion inhibitor globally recognized, it has become one of the most essential and widely applied raw materials for compounding high-efficiency water treatment formulations. Featuring a unique molecular structure combining phosphonic acid group and carboxylic acid group, PBTC delivers far more stable and superior comprehensive performance than traditional organic phosphonate products.
This product shows outstanding adaptability for harsh industrial water quality conditions, including high temperature, high water hardness, high alkalinity, high pH value and high concentration ratio circulating water systems. It exhibits excellent scale inhibition effect on common hard scales such as calcium carbonate scale, calcium phosphate scale and calcium sulfate scale, effectively preventing scale deposition and crystallization on the surface of heat exchangers, boilers, cooling towers and pipeline equipment.
In addition to remarkable scale inhibition capacity, PBTC possesses excellent metal corrosion inhibition performance, which can form a dense protective film on carbon steel, stainless steel and other metal surfaces to reduce equipment corrosion and extend the service life of industrial water system equipment. It features strong thermal stability, not easy to decompose under long-term high-temperature operating conditions, and maintains stable chemical activity in complex water environments.
Moreover, PBTC has good biodegradability, low environmental pollution and wide compatibility with other water treatment agents, making it highly suitable for formula compounding. With low effective dosage and high treatment efficiency, it can effectively improve the concentration multiple of circulating water, reduce water discharge and save industrial water consumption, bringing significant economic and environmental benefits for industrial circulating cooling water systems, boiler water systems, oilfield water injection systems and industrial wastewater treatment projects.
| 2-Phosphonobutane-1,2,4-tricarboxylic acid Chemical Properties |
| Melting point | -15 °C |
| Boiling point | 545.2±60.0 °C(Predicted) |
| density | 1.25 (50% aq.) |
| vapor pressure | 0Pa at 25℃ |
| refractive index | 1.579 |
| solubility | Completely miscible in water |
| pka | 1.14±0.10(Predicted) |
| form | clear liquid |
| color | Colorless to Light yellow |
| Water Solubility | 909g/L at 20℃ |
| Cosmetics Ingredients Functions | BUFFERING ANTICORROSIVE CHELATING |
| InChI | InChI=1S/C7H11O9P/c8-4(9)1-2-7(6(12)13,3-5(10)11)17(14,15)16/h1-3H2,(H,8,9)(H,10,11)(H,12,13)(H2,14,15,16) |
| InChIKey | SZHQPBJEOCHCKM-UHFFFAOYSA-N |
| SMILES | C(C(O)=O)C(P(O)(O)=O)(C(O)=O)CCC(O)=O |
| LogP | -1.66 at 25℃ |
| CAS DataBase Reference | 37971-36-1(CAS DataBase Reference) |
| EPA Substance Registry System | 2-Phosphono-1,2,4-butanetricarboxylic acid (37971-36-1) |
| Safety Information |
| Hazard Codes | Xi;Xn,Xn,Xi |
| Risk Statements | 34 |
| Safety Statements | 26-45 |
| RIDADR | UN 3265 |
| TSCA | TSCA listed |
| HS Code | 2931.90.9051 |
| HazardClass | 8 |
| PackingGroup | III |
PBTC ranks among the most widely adopted and highest-performance raw materials for formulating high-efficiency scale and corrosion inhibitors. Meanwhile, it serves as an outstanding stabilizer for zinc salts, effectively maintaining zinc ion solubility and preventing zinc salt precipitation under alkaline water conditions.
It is extensively applied for corrosion and scale control in industrial circulating cooling water systems and oilfield water injection systems. Thanks to its superior thermal stability and tolerance to harsh water environments, PBTC performs excellently under high temperature, high hardness, high alkalinity, high pH and high concentration ratio operating conditions. It exhibits remarkable synergistic effects when compounded with zinc salts and water treatment copolymers, greatly boosting the overall scale inhibition and corrosion inhibition performance of the blended formulations.
Beyond conventional water treatment scenarios, PBTC functions as an efficient chelating agent and metal cleaning agent in the washing industry. It can tightly chelate calcium, magnesium and other metal ions in water, eliminate mineral sediments on metal surfaces, and is applicable for industrial metal surface cleaning and pre-treatment processes.
Additionally, PBTC can be deployed in low & medium pressure boiler water systems, reverse osmosis membrane anti-scaling treatment, as well as wastewater conditioning for petrochemical, power, metallurgy and textile industries to mitigate scale deposition and metal corrosion, extend the service life of heat exchangers, pipelines and other water-handling equipment, and reduce maintenance downtime and operating costs.
