Hexamethylene diisocyanate (HDI)

CAS : 822-06-0

Hexamethylene diisocyanate (HDI) – also known as 1,6-diisocyanatohexane is the organic compound with the formula C8H12N2O2. It is classified as an aliphatic diisocyanate monomer used as raw material in the synthesis of polyurethane resins (PUR). It is a colourless to yellowish liquid, toxic, with a pungent odor. HDI is not miscible with water but easily soluble with organic solvents. 

Production

Compared to other diisocyanate, HDI is produced in small quantities by phosgenation of hexamethylenediamine. With Isophorone diisocyanate (IPDI), HDI accounting only for approximately 5% of the global diisocyanate market. 

HDI vapors are six times heavier than air. This compound can react violently with alcohols in the presence of bases if it is not sufficiently diluted and also reacts with water.

HDI is also sold oligomerized as the trimer named Biuret. Although more viscous in these forms, it reduces the volatility and toxicity.

Uses

Aliphatic diisocyanates are mainly used in specialty applications, such as polyurethane resins (PUR)  and polyurethane enamel coatings which are resistant to abrasion and degradation by ultraviolet light. These properties are particularly desirable in, for instance, the exterior paint applied to aircraft and vessels.

HDI provides flexibility in the material in which it is used. Typical applications are resins for coatings and inks, elastomers and TPU, Leather and textile.

Arpadis is one of the largest chemical distributor in Europe.

Arpadis is handling the storage, transport, export & import formalities of hexamethylene Diisocyanate (HDI) globally.