diisotsüanaadi

Diisotsüanaat is a chemical compound with the formula C2H2N2O2. It belongs to the class of organic compounds known as isocyanates, characterized by the functional group -N=C=O. Diisocyanates contain two such functional groups within a single molecule. The simplest and most common diisocyanates are aliphatic and aromatic. Aliphatic diisocyanates, such as hexamethylene diisocyanate (HDI), are generally less reactive and are often used in coatings and adhesives where UV stability and flexibility are important. Aromatic diisocyanates, like toluene diisocyanate (TDI) and methylene diphenyl diisocyanate (MDI), are more reactive and are widely used in the production of polyurethane foams, elastomers, and coatings.

The reactivity of the isocyanate group with compounds containing active hydrogen atoms, such as alcohols and amines, is the basis for their industrial applications. The reaction with polyols (compounds with multiple hydroxyl groups) is particularly important for the formation of polyurethanes, a versatile class of polymers. Depending on the specific diisocyanate and polyol used, as well as other additives, polyurethanes can range from flexible foams found in furniture and bedding to rigid foams used for insulation, and durable elastomers used in footwear and automotive parts.

Diisocyanates are typically manufactured through the phosgenation of diamines. However, due to the toxicity of phosgene, alternative, phosgene-free production routes are also being developed. Handling diisocyanates requires caution as they can be respiratory sensitizers and irritants. Exposure can lead to occupational asthma. Therefore, appropriate personal protective equipment and ventilation are essential when working with these chemicals.