Description
Isophorone diisocyanate (IPDI) (CAS No. 4098-71-9) is
a clear to pale-yellow liquid with a camphorlike odor
which is insoluble in water and miscible with most
common organic solvents. IPDI exists in two conformers,
cis and trans. Their reactivities are similar and each
conformer is an asymmetrical molecule with the secondary
isocyanate group being more reactive than the primary
isocyanate group. Since the substance does not contain any
groups that might oxidize or spontaneously ignite, it is not
expected that IPDI would self-ignite, oxidize, or explode at
ambient conditions. The water solubility is approximately
15 mg l-1 at 23 ℃, and hydrolysis with a half-life of
about an hour leads to polymers or to the corresponding
diamine.
Chemical Properties
colourless or slightly yellow liquid
Chemical Properties
Isophorone diisocyanate is a liquid with a vapour pressure which is significantly lower than that of tolylene diisocyanate.
Uses
Isophorone diisocyanate (IPDI) is used in theproduction of high-quality coatings, polyurethane paints, and varnishes and as an elastomer for casting compounds..
Uses
Yields polyurethanes with high stability, resistance to light discoloration, and chemical resistance.
Uses
Isophorone diisocyanate is used in the manufacture of polyurethane with high stability, resistance to light discoloration and chemical resistance; used in paints and
varnishes for hardness, flexibility, abrasion, chemical resistance to chalking and weathering; as an elastomer applicable for casting
compounds and mastics to highly flexible textile coatings; foams; hard industrial coatings; manufacture of contact lenses; curing.
Definition
ChEBI: A diisocyanate in which the two isocyanate groups are linked by an isophorone substituent.
Preparation
Isophorone diisocyanate (IPDI) is prepared by the phosgenation of isophorone diamine (l-amino-3-aminomethyl-3,5,5-trimethylcydohexane):
General Description
A clear to light-yellow liquid. Slightly denser than water and insoluble in water. Toxic by inhalation and skin absorption. Very irritating to skin. Used to make polyurethane coatings.
Air & Water Reactions
Insoluble in water. Isophorone diisocyanate may be sensitive to moisture.
Reactivity Profile
Isophorone diisocyanate reacts with all substances containing active hydrogen atoms such as water, alcohols, phenols, amines, mercaptans, amides, urethanes and ureas.
Hazard
A severe irritant, toxic by skin absorption.
Health Hazard
Isophorone diisocyanate is highly toxic by inhalation and moderately toxic through the skin. (Non-Specific -- Isocyanates) People with skin or respiratory problems should avoid exposure.
Health Hazard
Like most other isocyanates, IPDI exhibitsmoderate toxicity via inhalation. The acutetoxic symptoms are somewhat similar tothose of toluene-2,4- diisocyanate and diphenylmethane-4,4'-diisocyanate. Thus thetoxicity of such types is a characteristic ofthe -N=C=O functional group and to agreat extent is independent of the nature ofthe ring.
Inhalation of its vapor can cause bronchitis, asthma, tightness of chest, and dyspnea in humans. Recovery from these effectsmay occur in a short period from a lowconcentration exposure.
IPDI is an irritant to the skin and eyes.Exposure to this compound produces skinsensitization and eczema. Its oral toxicity isvery low.
LC50 value, inhalation (rats): 123 mg/m
3/4 hrLD50 value, skin (rats): 1060 mg/m
3There is no report of its carcinogenic orreproductive effects in animals or humans.
Fire Hazard
When heated to decomposition, Isophorone diisocyanate emits toxic fumes of nitrogen oxides.
Environmental Fate
IPDI is a synthetic organic chemical, which does not occur
naturally in the environment. At room temperature, it is
a liquid. It is miscible with alcohol, diglycol, monoethyl
ether, ether, acetone, carbon tetrachloride, benzene, chlorobenzene,
kerosene, and olive oil. IPDI decomposes in
water producing CO2, which can produce significant pressure
in a closed container. Upon contact with water or
moist air, IPDI will react to form stable, insoluble polyurea
solids. This reactivity dramatically limits the mobility of
these products in the event of a spill (spills are localized
and have only transient impact), and the products will tend
to remain in, and react within, the environment to which
they are released. IPDI is not readily biodegradable. It reacts
with water forming solid insoluble polyurea, isophorone
diamine (IPDA), and CO2, thus the predominant removal
mechanism is expected to be hydrolysis. The rate constant
of the OH radical sensitized indirect photodegradation
of isophorone diisocyanate corresponds to a half-life of
1.8 days at a 24 h mean OH radical concentration of
500 000 molecules per cm
3. A preliminary hydrolysis test
resulted in a dissipation half-life of 0.84 h (approximately
50 min) at 23 ℃. Polyurea is more or less inert and – due
to its molecular size – not bioavailable. No biodegradation
(0% degradation within 28 days) was observed in a manometric
respiratory test performed with domestic, nonadapted
activated sludge. As no degradation occurred in the
test on ready biodegradability, it is not expected that
a significant degradation would occur in a simulation test
(water and soil). The test substance is considered as
nonbiodegradable in surface water, sediment, and soil.
However, biodegradation is considered as irrelevant as
primary degradation step anyway because immediate hydrolysis takes place. Due to hydrolysis in water, bioaccumulation
of IPDI is not expected. The bioaccumulation
potential of the hydrolysis product IPDA is considered to
be low (log Kow = 0.99). There are no data on terrestrial
bioaccumulation available.
Toxicity evaluation
The toxicological properties of isocyanates are attributed to
the –N=C=O group. The consequence is that in the
hydrolysis of IPDI predominantly polyurea molecules are
formed with liberation of CO2. The polyurea molecules are
insoluble in water. Beside these insoluble main hydrolysis
products, there are minor amounts of other hydrolysis
products having a low to moderate molecular weight and
these are more or less water soluble (e.g., isophorone
diamine). The local toxic effect of the substance IPDI
is not related to metabolic mechanisms, because it is
a simple destruction of membranes due to corrosivity of the
substance.
Waste Disposal
Disposal is by chemical incineration of IPDIsolution in a combustible solvent.
