polyisocyanaattien

Polyisocyanates are a class of organic compounds characterized by the presence of multiple isocyanate functional groups (–N=C=O) in their molecular structure. These compounds are typically produced through the phosgenation of diamines or through non-phosgene routes involving the thermal decomposition of urethanes. Polyisocyanates are highly reactive, particularly with nucleophiles containing active hydrogen atoms, such as alcohols, amines, and water. This reactivity is the basis for their widespread use as key components in the production of polyurethanes.

The primary application of polyisocyanates is in the synthesis of polyurethane polymers. When reacted with polyols (compounds with multiple hydroxyl groups), they form urethane linkages, creating a versatile range of materials. The specific properties of the resulting polyurethane, such as its flexibility, hardness, and resistance to chemicals and abrasion, can be tailored by selecting different types of polyisocyanates and polyols. Common examples of polyisocyanates include toluene diisocyanate (TDI) and methylene diphenyl diisocyanate (MDI). These are used in the manufacturing of foams, coatings, adhesives, sealants, and elastomers. Due to their reactivity, polyisocyanates require careful handling and storage to prevent unwanted reactions with moisture or other active hydrogen-containing substances.