ГЕКСАМЕТИЛЕНДИИЗОЦИАНАТ

Описание

This diisocyanate compound is used in the manufacture of various polyurethane products: elastic and rigid foams, paints, lacquers, adhesives, bin ding agents, synthetic rubbers, and elastomeric fibers.

Химические свойства

Hexamethylene diisocyanate is a colorless liquid. Sharp, irritating odor.

Использование

Hexamethylene diisocyanate (HDI) is one of the most common aliphatic disocyanates, It is a monomer used in the production of polyurethane foams and exceptionally high-quality coatings, and is found in some industrial paints and spray painting operations. It is a compound which reacts readily with water and alcohols (Von Burg 1993). It has a vapor pressure of 0.05 mm Hg at room temperature, but can be present in aerosol form allowing a potentially higher exposure to individuals. The HDI-BT trimer is often present for similar industrial uses. It would be expected to have a lower vapor pressure; however, the aerosol form can also be present, allowing potentially higher exposure of HDI-BT to individuals. Hexamethylene diisocyanate reacts slowly with water to form carbon dioxide (HSDB 1996). The base-catalyzed reaction of Hexamethylene diisocyanate with alcohols should be carried out in inert solvents; the reaction may occur with explosive violence in the absence of solvents (NFPA 1994).

Подготовка

Hexamethylene diisocyanate (HDI) is prepared by the phosgenation of hexamethylenediamine (section lO.2.2(b)):
H2N-(CH2)6-NH2--COCl2-->OCN-(CH2)6-NCO
Hexamethylene diisocyanate is a liquid with a volatility of the same order as that of tolylene diisocyanate. It is respiratory irritant and also has powerful effects on the skin and eyes. Hexamethylene diisocyanate was one of the first diisocyanates utilized for making polyurethanes, being used to prepare fibres and moulding compounds. These applications are no longer of importance but hexamethylene diisocyanate now finds use mainly in coatings which are more light stable than those based on aromatic isocyanates.

прикладной

Hexamethylene diisocyanate is an aliphatic diisocyanate monomer typically used to produce oligomers and prepolymers that when combined with a polyol produce light-stable polyurethane.
Highly reactive 1,6-hexamethylene diisocyanate (HMDI) was used to synthesize lactic acid polymers from oligomers by the addition of 2,2′-bis(2-oxazoline) (BOX) as chain extenders. Self-healing ability was rendered to polyurethane elastomer by synthesizing alkoxyamine-based diol and reacting it with tri-functional homopolymer of HMDI and polyethylene glycol (PEG). Plastic optical fiber (POF) was prepared by the bulk homopolymerization of HMDI catalyzed by Tin(II)-2 ethylhexanoate (SnOct).

Определение

ChEBI: A diisocyanate compound with the two isocyanates linked by a hexane-1,6-diyl group.

Общее описание

A colorless crystalline solid. Toxic by ingestion and is strongly irritating to skin and eyes. 1,6-Diisocyanatohexane is used to make nylon.

Реакции воздуха и воды

Contact with moisture or temperatures over 399°F may cause polymerization. Soluble in water.

Профиль реактивности

1,6-Diisocyanatohexane reacts with water. Base-catalyzed reactions of 1,6-Diisocyanatohexane with alcohols may be explosively violent in the absence of diluting solvents. 1,6-Diisocyanatohexane is incompatible with strong bases, amines, acids and strong oxidizers. 1,6-Diisocyanatohexane is also incompatible with metal compounds and surface active materials. .

Опасность

Combustible.

Угроза здоровью

HDI is moderately toxic by inhalation. Inhumans the acute toxic symptoms could bewheezing, dyspnea, sweating, coughing, dif-ficulty in breathing, and insomnia. In addition, this compound can produce irritationof the skin, eyes, nose, and respiratory tract.Chronic exposure may cause obstruction ofairways and asthma.
The lethal concentration for rats frominhalation of this compound for 4 hourswas 60 mg/m3. The oral toxicity of thiscompound was found to be low in testanimals. The toxicity order was much higherwhen given intravenously.
LD50 value, oral (mice): 350 mg/kg
LD50 value, intravenous (mice): 5.6 mg/kg
There is no report of any carcinogenic orteratogenic study for this compound.

Пожароопасность

Combustible material: may burn but does not ignite readily. Substance will react with water (some violently) releasing flammable, toxic or corrosive gases and runoff. When heated, vapors may form explosive mixtures with air: indoors, outdoors and sewers explosion hazards. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapors may travel to source of ignition and flash back. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated or if contaminated with water.

Контактные аллергены

This diisocyanate compound is used in the manufac ture of various polyurethane products: elastic and rigid foams, paints, lacquers, adhesives, binding agents, synthetics rubbers, and elastomer fibers.

Профиль безопасности

Poison by inhalation and intravenous routes. Moderately toxic by ingestion and skin contact. Potentially explosive reaction with alcohols + base. When heated to decomposition it emits toxic fumes of NOx. See also CYANATES.

Возможный контакт

Used to make other chemicals, coat ings, and polyurethane. It is also used as a hardener in automobile and airplane paints.

Экологическая судьба

HDI is not readily soluble (low mg l^-1 range) in water. However, upon contact with water, reactivity is rapid with a half-life of 0.23 h at 23 ℃. This nonhomogeneous reaction is expected to produce principally polyureas. In the occupational environment, an aerosol can be formed by nebulization; however, with a vapor pressure of 0.007 hPa, HDI is expected to exist in the ambient atmosphere in its vapor state. As a vapor, HDI is expected to degrade in the atmosphere by reaction with hydroxyl radicals (half-life approximately 2 days). In direct contact with water, its rapid hydrolysis reduces the likelihood for HDI to bioaccumulate in the aquatic compartment or transfer to groundwater. Therefore, the rapid hydrolysis in an aquatic environment and relatively rapid degradation in atmosphere limits the ability of this substance to be bioaccumulative or persistent.

Перевозки

UN2281 Hexamethylene diisocyanate, Hazard Class: 6.1; Labels: 6.1-Poisonous materials.

Несовместимости

May form explosive mixture with air. Isocyanates are highly flammable and reactive with many compounds, even with themselves. Incompatible with oxi dizers (chlorates, nitrates, peroxides, permanganates, per chlorates, 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 flamma ble gases, including carbon dioxide; and, at the same time, may generate a violent release of heat increasing the con centration of fumes in the air. Incompatible with amines, aldehydes, alkali metals, ammonia, carboxylic acids, capro lactum, 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 acyl-chlorides 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. Temperatures above 200℃ can cause polymerization. Attacks copper.

Утилизация отходов

Disposal is by chemical incineration of HDIsolution in a combustible solvent.