Introduction:
Thiourea Dioxide (TDO or TUD), also known as Formamidine Sulfinic Acid (FAS), exists as a white crystalline powder. This compound demonstrates stability without strong reducing or oxidizing capabilities. Its solubility is 26.7g/l (at 20 ℃), with a pH of 5.0 in a saturated solution.
TDO exhibits remarkable stability even in solutions within the range of 20°C to 30°C. However, under heat or catalysis by alkali, it gradually decomposes, producing sulfoxylic acid through formamidine sulfinic acid, thus displaying a reducing action.
This compound serves as a new type of reducing agent, substituting sodium hydrosulfite, and finds widespread usage in the textile, papermaking, leather processing, pulp and board, photographic industries, and as bleaching and reducing agents. It is also a component in decolorization agents.
In the macromolecule material industry, TDO functions as a catalyst and stabilizer in resin production. Moreover, it's employed in organic synthesis for sensitizing materials, pharmaceuticals, fine chemicals, and spices. Additionally, it can be applied in the recycling and separation of heavy metals.
| Component | Specifications | Actual Lot Data |
| Purity | 99% Min | 99.49% |
| Moisture | 0.05% Max | 0.037% |
| Thiourea | 0.1% Max | 0.08% |
| Iron | 10PPM Max | 7PPM |
| Sulphate | 0.17% Max | 0.10% |