Formula C8H12N2O2 Molar mass 168.2 g/mol Melting point -67 °C | Density 1.05 g/cm³ Boiling point 255 °C Appearance Colourless liquid | |
Hexamethylene diisocyanate (HDI) is an organic compound in the class known as isocyanates. More specifically, it is an aliphatic diisocyanate. It is produced in relatively small quantities, accounting for (with isophorone diisocyanate) only 3.4% of the global diisocyanate market in the year 2000. Aliphatic diisocyanates are used in special applications, such as enamel coatings which are resistant to abrasion and degradation from ultraviolet light. These properties are particularly desirable in, for instance, the exterior paint applied to aircraft and vessels.
Contents

Synthesis
There are two steps to the synthesis of pure HDI:

Chemistry
HDI is a symmetrical molecule and thus has two isocyanate groups of equal reactivity.







References
Hexamethylene diisocyanate Wikipedia(Text) CC BY-SA