Description
Methylene bis (4-cyclohexylisocyanate) (HMDI) (CAS No.
5124-30-1) is a clear to pale yellow liquid, which is soluble in
acetone water and is incompatible with alcohols, amines,
bases, acids, and may slowly polymerize if heated above 50 ℃.
HMDI reacts with water and alcohol.
Chemical Properties
DMDI is a clear, colorless to light-yellow
liquid.
Chemical Properties
Liquid.Soluble in acetone;reacts with water or ethanol.
Uses
HMDI has excellent light stability and the stability of the six membered ring structure, has excellent weather resistance and excellent mechanical properties of polyurethane material, and is especially suitable for the production of high performance elastic body, a water polyurethane resin and UV resin.
Uses
In the manufacture of polymers
Uses
Methylene bis(4-cyclohexylisocyanate) isused to produce urethane foam with colorstability.
Definition
ChEBI: A diisocyanate consisting of dicyclohexylmethane with two isocyanate groups at the 4- and 4'-positions.
General Description
Clear colorless to light-yellow liquid.
Air & Water Reactions
Reacts with water to form CO2
Reactivity Profile
Isocyanates and thioisocyanates, such as Methylene-bis(4-cyclohexylisocyanate), are incompatible with many classes of compounds, reacting exothermically to release toxic gases. Reactions with amines, aldehydes, alcohols, alkali metals, ketones, mercaptans, strong oxidizers, hydrides, phenols, and peroxides can cause vigorous releases of heat. Acids and bases initiate polymerization reactions in these materials. Some isocyanates react with water to form amines and liberate carbon dioxide. Base-catalysed reactions of isocyanates with alcohols should be carried out in inert solvents. Such reactions in the absence of solvents often occur with explosive violence, [Wischmeyer(1969)].
Hazard
Strong skin and eye irritant. Respiratorysensitization and lower respiratory tract irritant.
Health Hazard
Studies on test animals indicate that methy-lene bis(4-cyclohexylisocyanate) is highlytoxic by an inhalation route and can causesevere skin reaction. Exposure to 20 ppmfor 5 hours produced irritation of the respiratory tract, tremor, convulsion, congestion oflungs, and edema in rats. The symptoms atlower levels were decreased as to respirationrate and pulmonary irritation.
Contact with the skin can produce severeirritation, erythema, and edema. The oraltoxicity of this compound is very low.
LD50 value, oral (rats): 9900 mg/kg
There is no report of the compound’smutagenicity or carcinogenicity.
Fire Hazard
Flash point data for Methylene-bis(4-cyclohexylisocyanate) are not available. Methylene-bis(4-cyclohexylisocyanate) is probably combustible.
Flammability and Explosibility
Non flammable
Safety Profile
Poison by inhalation.
Mildly toxic by ingestion. When heated to
decomposition it emits very toxic fumes of
NOx and CN-.
Potential Exposure
A potential danger to those involved
in the manufacture of this compound or its use in the production of light-stable, nonyellowing polyurethane resins.
First aid
If this chemical gets into the eyes, remove anycontact lenses at once and irrigate immediately for at least15 min, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts theskin, remove contaminated clothing and wash immediatelywith soap and water. Seek medical attention immediately.If this chemical has been inhaled, remove from exposure,begin rescue breathing (using universal precautions, includ-ing resuscitation mask) if breathing has stopped and CPR ifheart action has stopped. Transfer promptly to a medicalfacility. When this chemical has been swallowed, get medi-cal attention. Give large quantities of water and inducebreathing overexposure, as pulmonary edema may bedelayed. As first aid for pulmonary edema, a doctor orauthorized paramedic may consider administering a cortico-steroid spray.
Environmental Fate
HMDI is a synthetic organic chemical which does not occur
naturally in the environment. At room temperature, it is
a liquid. HMDI hydrolyzes rapidly in water, producing
methylene bis(4-cyclohexylamine). The half-life for HMDI is
approximately 2 h. Due to its rapid hydrolysis, transport
between environmental compartments is unlikely to occur.
Because of the rapid hydrolysis, the assessment of the
substance is based on the hydrolysis product
methylenebis(cyclohexylamine) and not on HMDI. The
hydrolysis product was not classified as a PBT (persistent,
bioaccumulative, toxic) substance. These data indicate that
HMDI is not readily biodegradable. However, due to its rapid
hydrolysis, HMDI is neither persistent in the water compartment
nor bioaccumulative. The calculated Koc-value indicates
that HMDI may strongly adsorb to soil; however, any emission
to the terrestrial compartment would be affected by
humidity and, therefore, terrestrial accumulation is not expected
to occur.
storage
Color Code—Blue: Health Hazard/Poison: Storein a secure poison location. Prior to working with thischemical you should be trained on its proper handling andstorage. Methylene bis(4-cyclohexylisocyanate) must bestored to avoid contact with alcohols, since violent reactionsoccur. Store in tightly closed containers in a cool,well-ventilated area away from moisture, heat, air, amines,strong bases, and chemically active metals.
Shipping
UN2206 Isocyanates, toxic, n.o.s. or Isocyanate
solutions, toxic, n.o.s., flash point .61C and boiling point
,300C, Hazard Class: 6.1; Labels: 6.1-Poisonous materials., Technical Name Required.
Toxicity evaluation
The toxicological properties of isocyanates are attributed to
the –N=C=O group. Skin sensitization with HMDI is
thought to be associated with the activation and proliferation
of lymphocytes in lymph nodes draining the site of
exposure. Analysis of the nature and kinetics of the cytokine
production (which regulates lymphocyte production) postexposure
to HMDI revealed that both interleukin-1 (IL-1)
and IL-6 were induced in a biphasic manner. The ordered
and transient pattern of cytokine production that occurs
during the afferent phase of contact sensitization suggests
that sequential cytokine signals may be involved in regulating
the characteristics of the response generated within
the draining lymph node.
Incompatibilities
May form explosive mixture with air.
Isocyanates are highly flammable and reactive with many
compounds, even with themselves. Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause
fires or explosions. Reaction with moist air, water or alcohols
may form amines and insoluble polyureas and react exothermically, releasing toxic, corrosive or flammable gases,
including carbon dioxide; and, at the same time, may generate a violent release of heat increasing the concentration of
fumes in the air. Incompatible with amines, aldehydes, alkali
metals, ammonia, carboxylic acids, caprolactum, alkaline
materials, glycols, ketones, mercaptans, hydrides, organotin
catalysts, phenols, strong acids, strong bases, strong reducing
agents such as hydrides, urethanes, ureas. Elevated temperatures or contact with acids, bases, tertiary amines, and acylchlorides may cause explosive polymerization. Attacks some
plastics, rubber and coatings. Contact with metals may evolve
flammable hydrogen gas. May accumulate static electrical
charges, and may cause ignition of its vapors. May slowly
polymerize if heated above 122F/50C. Contact with metals
may evolve flammable hydrogen gas.
Waste Disposal
Methylene bis(4-cyclohexylisocyanate) isdissolved in acetone or any other combustible solvent and burned in a chemicalincinerator equipped with an afterburner andscrubber.
