Methylene-bis(4-cyclohexylisocyanate)

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.

DMDI is a clear, colorless to light-yellow liquid.

Liquid.Soluble in acetone;reacts with water or ethanol.

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.

In the manufacture of polymers

Methylene bis(4-cyclohexylisocyanate) isused to produce urethane foam with colorstability.

ChEBI: A diisocyanate consisting of dicyclohexylmethane with two isocyanate groups at the 4- and 4'-positions.

Clear colorless to light-yellow liquid.

Reacts with water to form CO2

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)].

Strong skin and eye irritant. Respiratorysensitization and lower respiratory tract irritant.

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.

Flash point data for Methylene-bis(4-cyclohexylisocyanate) are not available. Methylene-bis(4-cyclohexylisocyanate) is probably combustible.

Non flammable

Poison by inhalation. Mildly toxic by ingestion. When heated to decomposition it emits very toxic fumes of NOx and CN-.

A potential danger to those involved in the manufacture of this compound or its use in the production of light-stable, nonyellowing polyurethane resins.

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.

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.

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.

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.

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.

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.

Methylene bis(4-cyclohexylisocyanate) isdissolved in acetone or any other combustible solvent and burned in a chemicalincinerator equipped with an afterburner andscrubber.