Diisotsüanaat

Diisotsüanaat refers to a class of organic compounds containing two isocyanate functional groups. The general formula for such compounds is R(NCO)2, where R represents an organic radical. These compounds are highly reactive due to the electrophilic nature of the carbon atom in the isocyanate group. The isocyanate group (-N=C=O) readily reacts with nucleophiles, particularly compounds containing active hydrogen atoms such as alcohols, amines, and water.

The most prominent and widely used diisotsüanaats are toluene diisocyanate (TDI) and methylene diphenyl diisocyanate (MDI). TDI exists as a mixture of isomers, primarily 2,4-TDI and 2,6-TDI. MDI is also a mixture, with monomeric MDI and polymeric MDI (PMDI) being common forms. These diisotsüanaats are crucial monomers in the production of polyurethanes.

The reaction between a diisotsüanaat and a polyol (a compound with multiple hydroxyl groups) is the fundamental process for creating polyurethane polymers. This polymerization reaction results in the formation of urethane linkages. Depending on the specific diisotsüanaat and polyol used, as well as reaction conditions, a wide range of polyurethane materials can be produced, including flexible foams, rigid foams, elastomers, coatings, adhesives, and sealants.

Diisotsüanaats are industrial chemicals and require careful handling due to their reactivity and potential health hazards, including respiratory sensitization. Exposure to isocyanates can lead to occupational asthma. Therefore, strict safety protocols and appropriate personal protective equipment are essential during their manufacture, transportation, and use.