Кислота уксусная

Описание

Уксусная кислота – это органический продукт со специфическим запахом и вкусом, представляет собой результат брожения спиртовых и углеводных компонентов либо скисания вин. Это вещество в форме винного уксуса было известно еще в Древней Греции и Древнем Риме. В более поздние времена алхимики научились производить более чистую субстанцию в результате перегонки. Кислота в виде кристаллов была выведена в 1700 году. Приблизительно в это же время химики определили ее формулу и выявили способность вещества к воспламенению. 

Описание

Acetic acid is a colourless liquid or crystal with a sour, vinegar-like odour and is one of the simplest carboxylic acids and is an extensively used chemical reagent. Acetic acid has wide application as a laboratory reagent, in the production of cellulose acetate mainly for photographic film and polyvinyl acetate for wood glue, synthetic fibres, and fabric materials. Acetic acid has also been of large use as a descaling agent and acidity regulator in food industries.

Использование

в производстве мономера винилового ацетата;
в качестве растворителя при производстве терефталевой кислоты;
сырье для полиэтилентерефталата;
задействуется при производстве ацетона, ацетата целлюлозы и разных искусственных пигментов.

Физические свойства

Acetic acid is a weak carboxylic acid with a pungent odor that exists as a liquid at room temperature. It was probably the first acid to be produced in large quantities. The name acetic comes from acetum, which is the Latin word for “sour” and relates to the fact that acetic acid is responsible for the bitter taste of fermented juices.

Вхождение

Reported found in vinegar, bergamot, cornmint oil, bitter orange oil, lemon petitgrain, various dairy products

История

Vinegar is a dilute aqueous solution of acetic acid. The use of vinegar is well documented in ancient history, dating back at least 10,000 years. Egyptians used vinegar as an antibiotic and made apple vinegar. Babylonians produced vinegar from wine for use in medicines and as a preservative as early as 5000 b.c.e. Hippocrates (ca. 460–377 b.c.e.), known as the “father of medicine,” used vinegar as an antiseptic and in remedies for numerous conditions including fever, constipation, ulcers, and pleurisy. Oxymel, which was an ancient remedy for coughs, was made by mixing honey and vinegar. A story recorded by the Roman writer Pliny the Elder (ca. 23–79 c.e.) describes how Cleopatra, in an attempt to stage the most expensive meal ever, dissolved pearls from an earring in vinegar wine and drank the solution to win a wager.

Использование

Acetic acid is used as table vinegar, as preservative and as an intermediate in the chemical industry, e.g. acetate fibers, acetates, acetonitrile, pharmaceuticals, fragrances, softening agents, dyes (indigo) etc. Product Data Sheet

Определение

ChEBI: Acetic acid is a simple monocarboxylic acid containing two carbons. It has a role as a protic solvent, a food acidity regulator, an antimicrobial food preservative and a Daphnia magna metabolite. It is a conjugate acid of an acetate.

Синтез

Чаще всего уксусная кислота добывается путем синтеза метил карбонилирования. Эта реакция метанола и монооксида углерода с получением уксусной кислоты имеет следующее уравнение:

СН3ОН + СО → СН3СООH

Общее описание

A colorless aqueous solution. Smells like vinegar. Density 8.8 lb / gal. Corrosive to metals and tissue.

Реакции воздуха и воды

Dilution with water releases some heat.

Профиль реактивности

ACETIC ACID, [AQUEOUS SOLUTION] reacts exothermically with chemical bases. Subject to oxidation (with heating) by strong oxidizing agents. Dissolution in water moderates the chemical reactivity of acetic acid, A 5% solution of acetic acid is ordinary vinegar. Acetic acid forms explosive mixtures with p-xylene and air (Shraer, B.I. 1970. Khim. Prom. 46(10):747-750.).

Опасность

Corrosive; exposure of small amounts can severely erode the lining of the gastrointestinal tract; may cause vomiting, diarrhea, bloody feces and urine; cardiovascular failure and death.

Угроза здоровью

Glacial acetic acid is a highly corrosive liquid. Contact with the eyes can produce mild to moderate irritation in humans. Contact with the skin may produce burns. Ingestion of this acid may cause corrosion of the mouth and gastrointestinal tract. The acute toxic effects are vomiting, diarrhea, ulceration, or bleeding from intestines and circulatory collapse. Death may occur from a high dose (20–30 mL), and toxic effects in humans may be felt from ingestion of 0.1–0.2 mL. An oral LD50 value in rats is 3530 mg/kg (Smyth 1956).
Glacial acetic acid is toxic to humans andanimals by inhalation and skin contact. Inhumans, exposure to 1000 ppm for a fewminutes may cause eye and respiratory tractirritation. Rabbits died from 4-hour exposureto a concentration of 16,000 ppm in air.

Воспламеняемость и взрывоопасность

Acetic acid is a combustible substance (NFPA rating = 2). Heating can release vapors that can be ignited. Vapors or gases may travel considerable distances to ignition source and "flash back." Acetic acid vapor forms explosive mixtures with air at concentrations of 4 to 16% (by volume). Carbon dioxide or dry chemical extinguishers should be used for acetic acid fires.

хранилище

Хранитьв прохладном, проветриваемом складе.

Беречь от огня, тепла. В холодный сезон должна поддерживаться температура выше 16℃, чтобы предотвратить затвердевание. В холодное время года температура должна быть выше 16℃, чтобы предотвратить застывание.

Держите контейнер герметичным. Должен быть отделен от окислителя и щелочи. Смешивания следует избегать.

Фармацевтические приложения

Glacial and diluted acetic acid solutions are widely used as acidifying agents in a variety of pharmaceutical formulations and food preparations. Acetic acid is used in pharmaceutical products as a buffer system when combined with an acetate salt such as sodium acetate. Acetic acid is also claimed to have some antibacterial and antifungal properties.

Сельскохозяйственное использование

Herbicide, Fungicide, Microbiocide; Metabolite, Veterinary Medicine: A herbicide used to control grasses, woody plants and broad-leaf weeds on hard surface and in areas where crops are not normally grown; as a veterinary medicine.

Торговое название

ACETUM®; ACI-JEL®; ECOCLEAR®; NATURAL WEED SPRAY® No. One; VOSOL®

Профиль безопасности

A human poison by an unspecified route. Moderately toxic by various routes. A severe eye and skin irritant. Can cause burns, lachrymation, and conjunctivitis. Human systemic effects by ingestion: changes in the esophagus, ulceration, or bleeding from the small and large intestines. Human systemic irritant effects and mucous membrane irritant. Experimental reproductive effects. Mutation data reported. A common air contaminant. A flammable liquid. A fire and explosion hazard when exposed to heat or flame; can react vigorously with oxidizing materials. To fight fire, use CO2, dry chemical, alcohol foam, foam and mist. When heated to decomposition it emits irritating fumes. Potentially explosive reaction with 5azidotetrazole, bromine pentafluoride, chromium trioxide, hydrogen peroxide, potassium permanganate, sodium peroxide, and phosphorus trichloride. Potentially violent reactions with acetaldehyde and acetic anhydride. Ignites on contact with potassium tert-butoxide. Incompatible with chromic acid, nitric acid, 2-amino-ethanol, NH4NO3, ClF3, chlorosulfonic acid, (O3 + diallyl methyl carbinol), ethplenediamine, ethylene imine, (HNO3 + acetone), oleum, HClO4, permanganates, P(OCN)3, KOH, NaOH, xylene

Безопасность

Acetic acid is widely used in pharmaceutical applications primarily to adjust the pH of formulations and is thus generally regarded as relatively nontoxic and nonirritant. However, glacial acetic acid or solutions containing over 50% w/w acetic acid in water or organic solvents are considered corrosive and can cause damage to skin, eyes, nose, and mouth. If swallowed glacial acetic acid causes severe gastric irritation similar to that caused by hydrochloric acid.
Dilute acetic acid solutions containing up to 10% w/w of acetic acid have been used topically following jellyfish stings.Dilute acetic acid solutions containing up to 5% w/w of acetic acid have also been applied topically to treat wounds and burns infected with Pseudomonas aeruginosa.
The lowest lethal oral dose of glacial acetic acid in humans is reported to be 1470 mg/kg.The lowest lethal concentration on inhalation in humans is reported to be 816 ppm.Humans, are, however, estimated to consume approximately 1 g/day of acetic acid from the diet.
LD₅₀ (mouse, IV): 0.525 g/kg
LD₅₀ (rabbit, skin): 1.06 g/kg
LD₅₀ (rat, oral): 3.31 g/kg

Возможный контакт

Acetic acid is widely used as a chemical feedstock for the production of vinyl plastics, acetic anhydride, acetone, acetanilide, acetyl chloride, ethyl alcohol, ketene, methyl ethyl ketone, acetate esters, and cellulose acetates. It is also used alone in the dye, rubber, pharmaceutical, food preserving, textile, and laundry industries. It is utilized, too; in the manufacture of Paris green, white lead, tint rinse, photographic chemicals, stain removers, insecticides, and plastics.

Канцерогенность

Acetic acid is a very weak tumor promoter in a multistage mouse skin model for chemical carcinogenesis, but was very effective in enhancing cancer development when applied during the progression phase of the model. Female SENCAR mice were initiated with a topical application of 7,12-dimethylbenzanthracene and 2 weeks later were promoted with 12-O-tetradecanoylphorbol- 13-acetate, twice weekly for 16 weeks. Topical treatment with acetic acid started 4 weeks later (40 mg glacial acetic acid in 200mL acetone, twice weekly) and continued for 30 weeks. Before treatment with acetic acid, each group of mice had approximately the same number of papillomas at the exposure site. After 30 weeks of treatment, mice treated with acetic acid had a 55% greater conversion of skin papillomas to carcinomas than vehicle-treated mice. Selective cytotoxicity to certain cells within the papilloma and a compensatory increase in cell proliferation were considered the most probable mechanism.

Экологическая судьба

Biological. Near Wilmington, NC, organic wastes containing acetic acid (representing 52.6% of total dissolved organic carbon) were injected into an aquifer containing saline water to a depth of approximately 1,000 feet below ground surface. The generation of gaseous components (hydrogen, nitrogen, hydrogen sulfide, carbon dioxide, and methane) suggests acetic acid and possibly other waste constituents, were anaerobically degraded by microorganisms (Leenheer et al., 1976).
Plant. Based on data collected during a 2-h fumigation period, EC50 values for alfalfa, soybean, wheat, tobacco, and corn were 7.8, 20.1, 23.3, 41.2, and 50.1 mg/m³, respectively (Thompson et al., 1979).
Photolytic. A photooxidation half-life of 26.7 d was based on an experimentally determined rate constant of 6 x 10^-13 cm³/molecule?sec at 25 °C for the vapor-phase reaction of acetic acid with OH radicals in air (Atkinson, 1985). In an aqueous solution, the rate constant for the reaction of acetic acid with OH radicals was determined to be 2.70 x 10^-17 cm³/molecule?sec (Dagaut et al., 1988).
Chemical/Physical. Ozonolysis of acetic acid in distilled water at 25 °C yielded glyoxylic acid which oxidized readily to oxalic acid before undergoing additional oxidation producing carbon dioxide. Ozonolysis accompanied by UV irradiation enhanced the removal of acetic acid (Kuo et al., 1977).

хранилище

Acetic acid 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.

Перевозки

UN2789 Acetic acid, glacial or Acetic acid solution, with .80 % acid, by mass, hazard class: 8; labels: 8-Corrosive material, 3-flammable liquid. UN2790 acetic acid solution, not ,50% but not .80% acid, by mass, hazard class: 8; labels: 8-Corrosive material; acetic acid solution, with .10% and ,50%, by mass, hazard class: 8; labels: 8-Corrosive material

Методы очистки

Usual impurities are traces of acetaldehyde and other oxidisable substances and water. (Glacial acetic acid is very hygroscopic. The presence of 0.1% water lowers its m by 0.2o.) Purify it by adding some acetic anhydride to react with water present, heat it for 1hour to just below boiling in the presence of 2g CrO3 per 100mL and then fractionally distil it [Orton & Bradfield J Chem Soc 960 1924, Orton & Bradfield J Chem Soc 983 1927]. Instead of CrO3, use 2-5% (w/w) of KMnO4, and boil under reflux for 2-6hours. Traces of water have been removed by refluxing with tetraacetyl diborate (prepared by warming 1 part of boric acid with 5 parts (w/w) of acetic anhydride at 60o, cooling, and filtering off, followed by distillation [Eichelberger & La Mer J Am Chem Soc 55 3633 1933]. Refluxing with acetic anhydride in the presence of 0.2g % of 2-naphthalenesulfonic acid as catalyst has also been used [Orton & Bradfield J Chem Soc 983 1927]. Other suitable drying agents include anhydrous CuSO4 and chromium triacetate: P2O5 converts some acetic acid to the anhydride. Azeotropic removal of water by distillation with thiophene-free *benzene or with butyl acetate has been used [Birdwhistell & Griswold J Am Chem Soc 77 873 1955]. An alternative purification uses fractional freezing. [Beilstein 2 H 96, 2 IV 94.] Rapid procedure: Add 5% acetic anhydride, and 2% of CrO3. Reflux and fractionally distil.

Несовместимости

Acetic acid reacts with alkaline substances.

Утилизация отходов

Dissolve or mix the material with a combustible solvent and burn in a chemical incinerator equipped with an afterburner and scrubber. All federal, state, and local environmental regulations must be observed

Регуляторный статус

GRAS listed. Accepted as a food additive in Europe. Included in the FDA Inactive Ingredients Database (injections, nasal, ophthalmic, and oral preparations). Included in parenteral and nonparenteral preparations licensed in the UK.