Product Description of 4,4'-Diamino-2,2'-Stilbenedisulfonic Acid CAS#81-11-8 Commonly referred to as Amsonic Acid, 4,4'-diamino-2,2'-stilbenedisulfonic acid appears as pale yellow crystalline powder. It is a water-soluble substance built upon a stilbene skeleton, bearing amino and sulfonic acid functional groups within its molecular structure.
This chemical is a core synthetic precursor for fluorescent whitening additives widely supplied to textile and papermaking sectors. It remains an indispensable raw material for manufacturing dyestuffs and light brightening agents.
4,4'-Diamino-2,2'-stilbenedisulfonic acid Chemical Properties
| Melting point | 300 °C |
| Density | 1.4732 (rough estimate) |
| Vapor pressure | 1.3hPa at 25℃ |
| Refractive index | 1.6510 (estimate) |
| Storage temp | Keep in dark place,Inert atmosphere,Room temperature |
| Solubility | Aqueous Base (Slightly) |
| Pka | -1.58±0.50(Predicted) |
| Form | Crystalline Powder |
| Color | Cream to yellow-brown |
| Water Solubility | <0.1 g/100 mL at 23 ºC |
| Merck | 14595 |
| BRN | 629516 |
| Stability | Stable. Combustible. Incompatible with iron, strong oxidizing agents. |
| LogP | -1.7--1.42 at 25℃ |
| CAS DataBase Reference | 81-11-8(CAS DataBase Reference) |
| EPA Substance Registry System | Amsonic acid (81-11-8) |
Safety Information
| Hazard Codes | C,Xn |
| Risk Statements | 34-22-36/37/38-20/21/22 |
| Safety Statements | 24/25-45-36/37/39-26-22 |
| RIDADR | UN 2583 |
| RTECS | WJ6603000 |
| TSCA | Yes |
| HS Code | 29215900 |
| Hazardous Substances Data | 81-11-8(Hazardous Substances Data) |
Product Applications of 4,4'-Diamino-2,2'-stilbenedisulfonic acid CAS#81-11-8 This compound finds its main deployment in the fabrication of fluorescent whitening agents, alongside the synthesis of Direct Yellow G and Direct Yellow R dyestuffs. It can also be incorporated into agrochemical formulations.
Furthermore, it acts as a vital synthetic building block for preparing various dyes and optical brighteners.
