1,4 - Диоксан

Описание

1,4-dioxane is a clear liquid with ether-like odour. It is highly flammable and forms explosive peroxides in storage (rate of formation increased by heating, evaporation, or exposure to light). 1,4-Dioxane is incompatible with oxidising agents, oxygen, halogens, reducing agents, and moisture. Industrial applications of 1,4-dioxane are extensive, for instance, as solvent for cellulose acetate, ethyl cellulose, benzyl cellulose, resins, oils, waxes, and some dyes; as a solvent for paper, cotton, and textile processing; and for various organic and inorganic compounds and products. It is also used in automotive coolant liquid and in shampoos and other cosmetics as a degreasing agent and as a component of paint and varnish. Human exposures to 1,4-dioxane have been traced to multiple occupations and breathing of contaminated workplace air and drinking polluted water. Industrial uses of 1,4-dioxane are very many. For instance, it is used as solvent for celluloses, resins, lacquers, synthetic rubbers, adhesives, sealants, fats, oils, dyes, and protective coatings; as a stabiliser for chlorinated solvents and printing inks; and as a wetting and dispersing agent in textile processing agrochemicals and pharmaceuticals, in different processing of solvent-extraction processes, and in the preparation and manufacture of detergents.

Химические свойства

1,4-Dioxane is a colorless, stable liquid with a faint, pleasant odor. Although it has been known as far back as 1863, it was not until 1929 that is became commercially available. It is chemically a di-ether obtained by the loss of water from two molecules of ethylene glycol. It is completely soluble in water, as well as most organic solvents. It is freely soluble in mineral, vegetable, blown and heat-bodied oils, and oil soluble dyes. Most waxes are more readily soluble in dioxane when heated and examples of these are beeswax, carnauba, montan, paraffin, gilsonite, and Japan wax.

Физические свойства

Clear, colorless, very flammable, volatile liquid with a faint pleasant, ether-like odor. Experimentally determined detection and recognition odor threshold concentrations were 2.9 mg/m³ (800 ppb_v) and 6.5 mg/m³ (1.8 ppm_v), respectively (Hellman and Small, 1974).

Использование

1,4-Dioxane, the six-member cyclic diether, is used as an aluminum inhibitor in chlorinated solvents like 1,1,1-trichloroethane and as a solvent for certain resins and polymers.

Определение

ChEBI: A dioxane with oxygen atoms at positions 1 and 4.

Общее описание

A clear colorless liquid with a faint ethereal odor. Flash point 55°F. Slightly denser than water and soluble in water. Vapors heavier than air. Susceptible to autooxidation to form peroxides.

Реакции воздуха и воды

Highly flammable. When exposed to air 1,4-Dioxane undergoes autooxidation with formation of peroxides. In the distillation process peroxides will concentrate causing violent explosion. Water soluble.

Профиль реактивности

1,4-Dioxane is a flammable liquid; when exposed to air 1,4-Dioxane undergoes autooxidation with formation of peroxides. In the distillation process peroxides will concentrate causing violent explosion. The addition complex with sulfur trioxide (1:1) sometimes decomposes violently on storing at room temperature [Sisler, H. H. et al., Inorg. Synth., 1947, 2, p. 174]. Evaporation of boron trifluoride in aqueous 1,4-Dioxane with nitric acid led to an explosion upon addition of perchloric acid [MCA Guide, 1972, p. 312]. Explosive reaction with Raney nickel catalyst above 210° C {Mozingo R., Org. Synth., 1955, Coll. Vol. 3, p. 182].

Угроза здоровью

The toxicity of 1,4-dioxane is low in testanimals by all routes of exposure. However,in humans the toxicity of this compoundis severe. The target organs are theliver, kidneys, lungs, skin, and eyes. Exposureto its vapors as well as the absorptionthrough the skin or ingestion can cause poisoning,the symptoms of which include drowsiness,headache, respiratory distress, nausea,and vomiting. It causes depression of centralnervous system. There are reports of humandeaths from subacute and chronic exposures todioxane vapors at concentration levels rangingbetween 500 and 1000 ppm. Serious healthhazards may arise from its injurious effects onthe liver, kidneys, and brain. Rabbits died ofkidney injury resulting from repeated inhalationof 1,4-dioxane vapors for 30 days (Smyth1956). It is an irritant to the eyes, nose, skin,and lungs. In humans, a 1-minute exposure to5000-ppm vapors can cause lacrimation.
LC50 value, inhalation (rats): 13,000 ppm/2 h
LD50 value, oral (mice): 5700 mg/kg
1,4-Dioxane is an animal carcinogen oflow potential. Ingestion of high concentrationsof this compound at a level of7000–18,000 ppm in drinking water for14–23 months caused nasal and liver tumorsin rats (ACGIH 1986). Guinea pigs developedlung tumors.

Воспламеняемость и взрывоопасность

Dioxane is a highly flammable liquid (NFPA rating = 3). Its vapor is heavier than air and may travel a considerable distance to a source of ignition and flash back. Dioxane vapor forms explosive mixtures with air at concentrations of 2 to 22% (by volume). Fires involving dioxane should be extinguished with carbon dioxide or dry powder extinguishers.
Dioxane can form shock- and heat-sensitive peroxides that may explode on concentration by distillation or evaporation. Samples of this substance should always be tested for the presence of peroxides before distilling or allowing to evaporate. Dioxane should never be distilled to dryness.

Профиль безопасности

Confirmed carcinogen with experimental carcinogenic, neoplastigenic, tumorigenic, and teratogenicdata. Poison by intraperitoneal route. Moderately toxic by ingestion and inhalation. Mildly toxic by skin contact. Human systemic effects by inhalation: lachrymation, conjunctiva irritation, convulsions, hgh blood pressure, unspecified respiratory and gastrointestinal system effects. Mutation data reported. An eye and slun irritant. The irritant effects probably provide sufficient warning, in acute exposures, to enable a worker to leave exposure before being seriously affected. Repeated exposure to low concentrations has resulted in human fatahties, the organs chefly affected being the liver and kidneys. A very dangerous fire and explosion hazard when exposed to heat or flame; can react vigorously with oxidizing materials. Violent reaction with (H2 + Raney Ni), AgClO4. Can form dangerous peroxides when exposed to air. Potentially explosive reaction with nitric acid + perchloric acid, Raney nickel catalyst (above 210°C). Forms explosive mixtures with decaborane (impactsensitive), triethynylaluminum (sensitive to heating or drying). Violent reaction with sulfur trioxide. Incompatible with sulfur trioxide. To fight fire, use alcohol foam, CO2, dry chemical. When heated to decomposition it emits acrid smoke and irritating fumes. See also GLYCOL ETHERS.

Описание

1,4-Диоксан органическое соединение, классифицируется как эфир. Под названием «диоксан» обычно понимают диоксан 1,4. Вещество растворимо в воде, спирте, легко смешивается с эфиром. Предел взрываемости в воздухе (по объему) равен от 1,97 % до 22,5%. Соединение часто называют просто диоксаном, потому что другие изомеры (1,2- и 1,3-) встречаются крайне редко. Может смешиваться с водой, спиртом, эфиром. Промышленным способом диоксан получают из этиленгликоля, хлорекса и окиси этилена.

Канцерогенность

1,4-Dioxane is reasonably anticipated to be a human carcinogen basedon sufficient evidence of carcinogenicity from studies in experimental animals.

Применение

Диоксан находит применение в органическом синтезе в качестве растворителя при проведении ряда важных процессов, например при высаждении солей органических аминов, получении такого важного реагента как диоксан дибромид, растворении ацетилцеллюлозы, минеральных и растительных масел, красок. Диоксан используется также как стабилизатор для 1,1,1-трихлорэтана для его хранения и транспортирования в алюминиевых ёмкостях.

хранилище

dioxane should be used only in areas free of ignition sources, and quantities greater than 1 liter should be stored in tightly sealed metal containers in areas separate from oxidizers. Containers of dioxane should be dated when opened and tested periodically for the presence of peroxides.

Получение

Диоксан получают, перегоняя с серной кислотой этиленгликоль или димеризацией окиси этилена, или взаимодействием с NaOH b,b'-дихлордиэтилового эфира.

Несовместимости

Dioxane can form potentially explosive peroxides upon long exposure to air. Dioxane may react violently with Raney nickel catalyst, nitric and perchloric acids, sulfur trioxide, and strong oxidizing reagents.

Утилизация отходов

Excess dioxane and waste material containing this substance should be placed in an appropriate container, clearly labeled, and handled according to your institution's waste disposal guidelines.

Меры предосторожности

Workers Should be careful during handling of 1,4-Dioxane and avoid open flames, sparks and smoking. Workers should wear proper protectives since 1,4-Dioxane in known as hazardous, cause damage to eyes, respiratory tract, liver and kidney.