Isophorone diisocyanate

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Isophorone diisocyanate
Isophorone diisocyanate
Isophorone diisocyanate
CAS number 4098-71-9 YesY
PubChem 169132
ChemSpider 147926 YesY
ChEBI CHEBI:53214 YesY
Jmol-3D images Image 1
Molecular formula C12H18N2O2
Molar mass 222.3 g/mol
Appearance Colourless liquid
Density 1.062 g/cm3 @ 20 °C, liquid
Melting point −60 °C (−76 °F; 213 K)
Boiling point 158 °C (316 °F; 431 K) at 1.33 kPa
Flash point 155 °C (311 °F; 428 K) (PMCC)
Related compounds
Related isocyanates Hexamethylene diisocyanate
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 YesY (verify) (what is: YesY/N?)
Infobox references

Isophorone diisocyanate (IPDI) 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 hexamethylene diisocyanate) only 3.4% of the global diisocyanate market in the year 2000.[1] Aliphatic diisocyanates are used, not in the production of polyurethane foam, but 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.


There are five steps to the synthesis of pure IPDI:[1]

  • Condensation: Conversion of acetone with a catalyst to produce isophorone
  • Hydrocyanation: Reaction of the isophorone with hydrogen cyanide to form isophorone nitrile
  • Reductive amination: Reaction of the isophorone nitrile with ammonia, hydrogen and a catalyst, to form a mixture of isophorone diamine conformers (25/75 cis/trans)
  • Phosgenation: Reaction of the isophorone diamine with phosgene to form a crude mixture containing IPDI conformers (25/75 cis/trans)
  • Purification: Distillation of the crude IPDI to extract pure IPDI


IPDI exists in two stereoisomers, cis and trans. Their reactivities are similar. Each stereoisomer is an unsymmetrical molecule, and thus has isocyanate groups with different reactivities. The primary isocyanate group is more reactive than the secondary isocyanate group.[1]

See also[edit]


  1. ^ a b c Randall, David; Lee, Steve (2002). The Polyurethanes Book. New York: Wiley. ISBN 0-470-85041-8. 

External links[edit]