Toluene diisocyanate, abbreviated as TDI, is a highly reactive organic chemical compound that is widely used in various industries, especially in the production of polyurethanes. Polyurethanes are polymeric materials that have a wide variety of applications due to their unique properties such as strength, flexibility, and thermal insulation.

Chemical structure and types of TDI

TDI has two isocyanate groups (-NCO) attached to the benzene ring. This chemical structure gives TDI its very high reactivity. The two main isomers of TDI are:

2,4-TDI: In this isomer, the two isocyanate groups are located at positions 2 and 4 of the benzene ring.

2,6-TDI: In this isomer, the two isocyanate groups are located at positions 2 and 6 of the benzene ring.
TDI Properties
High Reactivity: TDI is highly reactive due to the presence of isocyanate groups and reacts rapidly with compounds containing active hydrogen such as water, alcohols and amines.
Toxicity: TDI is a toxic chemical and contact with it can cause irritation of the skin, eyes and respiratory tract. Inhalation of TDI vapors can lead to serious respiratory problems.
Flammability: TDI is flammable and can catch fire if exposed to flame or high heat.

TDI Applications

TDI is used as an important raw material in the production of polyurethanes. Polyurethanes produced using TDI have a wide range of applications in various industries, including:

Construction industry: thermal and acoustic insulation, construction foams, adhesives, sealants
Automotive industry: seats, interior upholstery, thermal and acoustic insulation
Furniture industry: soft and rigid foams, furniture upholstery
Clothing industry: synthetic leather, thermal insulation

Polyurethane production process

In the polyurethane production process, TDI reacts with polyols. Polyols are organic compounds that have at least two hydroxyl groups (-OH) in their structure. The reaction between TDI and polyols results in the formation of polyurethane.