June 29, 2022
TDI is the abbreviation of toluene diisocyanate for industrial use,TDI(toluene diisocyanate) is a commonly used polyisocyanate, and polyisocyanate is a polyurethane (PU) material and an important basic raw material toluene diisocyanate is mainly used in the production of soft polyurethane foam and polyurethane elastomer coating adhesive。
TDI commonly used in the polyurethane industry is a mixture of 2,4-TDI and 2,6-TDI isomers, including three commonly used grades: TDI-80/20, TDI-100 and TDI-65/35. The preceding figures indicate the amount of 2, 4-TDI in the composition. For example, 80 in TDI-80/20 indicates that it consists of 80% 2, 4-TDI and 20% 2, 6-TDI; The 100 in TDI-100 means almost all 2, 4-TDI(about 98%), and 2, 6-TDI isomers are rare.
TDI mainly exists in paint in decoration, and free TDI beyond the standard will cause harm to the human body, mainly sensitizing and stimulating effects, such as eye pain, tears, conjunctival congestion, cough, chest tightness, shortness of breath, asthma, red papules, macular papules, contact irritability and other symptoms. The international limit for free TDI is less than 0.5%. Toluene diisocyanate is a colorless or light yellow transparent liquid with a pungent odor, which turns yellow under ultraviolet radiation. Easy polymerization in alloy steel container by heating; It can react with hydroxyl, water, amine and compounds with active hydrogen to form carbamate, urea, carbamide and biuret.
TDI and waste barrels should be disposed in strict accordance with national, provincial and local regulations. They can be first reacted with polyols to produce foam, and then disposed or incinerated. Or reaction with liquid decontamination agent to generate urea derivatives. For drums containing TDI, 2 to 5 liters of decontamination solution can be injected into the drums first, and cleaned by spraying or rolling. Then, the drums can be opened for 4 to 6 hours to allow the full reaction, and finally washed with water.