Toluene diisocyanate (TDI) is an aromatic diisocyanate that typically appears as a clear to pale yellow liquid with a sharp, pungent odor. It is insoluble in water but miscible with most common organic solvents.

TDI (CAS No. 26471-62-5) consists of two isomers: toluene-2,4-diisocyanate (2,4-TDI, CAS No. 584-84-9) and toluene-2,6-diisocyanate (2,6-TDI, CAS No. 91-08-7). Commercial TDI is supplied in various isomer ratios, with an 80:20 blend of 2,4-TDI and 2,6-TDI being the most common. TDI is widely used in the chemical industry and has historically accounted for a substantial share of the global isocyanate market.

Toluene diisocyanate Chemical Properties

Product Application of Toluene Diisocyanate CAS#26471-62-5

The isocyanate groups in toluene diisocyanate (TDI) react with hydroxyl groups to form urethane linkages. This property makes TDI an important raw material for manufacturing flexible polyurethane foams used in furniture, bedding, automotive seats, and seating systems for commercial transportation.

TDI is also used to produce polyurethane elastomers for applications such as automotive bumper covers, industrial rollers, sports footwear, and various mechanical products. In addition, it serves as a raw material for coatings, including metal coatings, wood coatings, and high-performance anticorrosion coatings.

Rigid polyurethane foam based on TDI is used in household refrigerators and residential construction, including wall sheathing and commercial roofing. Spray-applied rigid polyurethane foam formulated with TDI can also provide insulation for truck trailers, railway freight cars, and overseas shipping containers. Furthermore, moisture-curing TDI-based coatings are used as sealants and floor finishes for wood and concrete surfaces.