Isophorone diisocyanate (IPDI) is an organic compound in the class known as
isocyanate
In organic chemistry, isocyanate is the functional group with the formula . Organic compounds that contain an isocyanate group are referred to as isocyanates. An organic compound with two isocyanate groups is known as a diisocyanate. Diisocyan ...
s. More specifically, it is an
aliphatic
In organic chemistry, hydrocarbons ( compounds composed solely of carbon and hydrogen) are divided into two classes: aromatic compounds and aliphatic compounds (; G. ''aleiphar'', fat, oil). Aliphatic compounds can be saturated, like hexane, or ...
diisocyanate. It is produced in relatively small quantities, accounting for (with
hexamethylene diisocyanate
Hexamethylene diisocyanate (HDI) is the organic compound with the formula (CH2)6(NCO)2. It is classified as an diisocyanate. It is a colorless liquid. It has sometimes been called HMDI but this not usually done to avoid confusion with Hydrogenate ...
) only 3.4% of the global diisocyanate market in the year 2000.
[{{cite book , first=David , last=Randall , author2=Lee, Steve , title=The Polyurethanes Book , publisher=Wiley , location=New York , year=2002 , isbn=0-470-85041-8
] Aliphatic diisocyanates are used, not in the production of
polyurethane
Polyurethane (; often abbreviated PUR and PU) refers to a class of polymers composed of organic chemistry, organic units joined by carbamate (urethane) links. In contrast to other common polymers such as polyethylene and polystyrene, polyurethan ...
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.
Synthesis
IPDI is obtained by
phosgenation
Phosgene is the organic chemical compound with the formula COCl2. It is a toxic, colorless gas; in low concentrations, its musty odor resembles that of freshly cut hay or grass. Phosgene is a valued and important industrial building block, espe ...
of
isophorone diamine
Isophorone diamine (usually shortened to IPDA) is a diamine with the formula (CH3)3C6H7(NH2)(CH2NH2). It is a colorless liquid. It is a precursor to polymers and coatings.
Production
It is usually produced as a mixture of the ''cis''- and ''tra ...
:
Chemistry
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.
See also
*
Methylene diphenyl diisocyanate
Methylene diphenyl diisocyanate (MDI) is an aromatic diisocyanate. Three isomers are common, varying by the positions of the isocyanate groups around the rings: 2,2′-MDI, 2,4′-MDI, and 4,4′-MDI. The 4,4′ isomer is most widely used, and i ...
*
Toluene diisocyanate
Toluene diisocyanate (TDI) is an organic compound with the formula CH3C6H3(NCO)2. Two of the six possible isomers are commercially important: 2,4-TDI (CAS: 584-84-9) and 2,6-TDI (CAS: 91-08-7). 2,4-TDI is produced in the pure state, but TDI is oft ...
*
Hexamethylene diisocyanate
Hexamethylene diisocyanate (HDI) is the organic compound with the formula (CH2)6(NCO)2. It is classified as an diisocyanate. It is a colorless liquid. It has sometimes been called HMDI but this not usually done to avoid confusion with Hydrogenate ...
*
Tetramethylxylene diisocyanate
References
External links
NIOSH Safety and Health Topic: Isocyanates from the website of the National Institute for Occupational Safety and Health (NIOSH)
Isocyanates