Этилацета

Описание

не имеющая цвета, подвижная жидкость с резким, характерным эфирным запахом, в небольших концентрациях приятным,  при увеличении содержания паров этилацетата в воздухе, запах становится очень резким и раздражает глаза и слизистую.

Химические свойства

Бесцветная подвижная жидкость с приятным сладковатым запахом. Молярная масса 88.11г/моль, температура плавления −83.6 °C, температура кипения 77,1 °C, плотность 0.9001 г/см³, n204 1.3724. Растворяется в воде 12 %(по массе), в этаноле, диэтиловым эфире, бензоле, хлороформе образует двойные азеотропные смеси с водой (т. кип. 70,4 °C, содержание воды 8,2 % по массе), этанолом (71,8; 30,8), метанолом (62,25; 44,0), изопропанолом (75,3; 21,0), CCl4 (74,7; 57), циклогексаном (72,8; 54,0) и тройную азеотропную смесь Э.: вода:этанол (т. кип. 70,3 °C, содержание соотв. 83,2, 7,8 и 9 % по массе).

Описание

Ethyl acetate (systematically, ethyl ethanoate, commonly abbreviated EtOAc or EA) is the organic compound with the formula CH₃COOCH₂CH₃. This colorless liquid has a characteristic sweet smell (similar to pear drops) and is used in glues, nail polish removers, decaffeinating tea and coffee, and cigarettes (see list of additives in cigarettes). Ethyl acetate is the ester of ethanol and acetic acid; it is manufactured on a large scale for use as a solvent. The combined annual production in 1985 of Japan, North America, and Europe was about 400,000 tons. In 2004, an estimated 1.3M tons were produced worldwide.

Химические свойства

Ethyl acetate has a pleasant ethereal fruity, brandy-like odor, reminiscent of pineapple, somewhat nauseating in high concentration. It has fruity sweet taste when freshly diluted in water. Ethyl acetate is probably one of the most used of all flavor chemicals by volume. Ethyl acetate is slowly decomposed by moisture and then acquires an acid status due to the acetic acid formed.

Физические свойства

Clear, colorless, mobile liquid with a pleasant, sweet fruity odor. Experimentally determined detection and recognition odor threshold concentrations were 23 mg/m³ (6.4 ppm_v) and 48 mg/m³ (13.3 ppm_v), respectively (Hellman and Small, 1974). Cometto-Mu?iz and Cain (1991) reported an average nasal pungency threshold concentration of 67,300 ppm_v.

Вхождение

Although it has been reported present in some natural fruital aromas and in some distillates (rum, rum ether), it has not been reported yet as a constituent of essential oils; it has been identified also in the petals of Magnolia fuscata. Reported found in many foods including fresh and cooked apple, apricot, banana (169 ppm), sweet and sour cherry, citrus peel oils and juices, blueberry, cranberry, black currants, raspberry, blackberry, guava, passion fruit, melon, peaches, papaya, pineapple, cabbage, onion, leek, potato, tomato (3 to 6 ppm), clove, ginger, vinegar, breads, cheeses (0.2 to 0.8 ppm), butter (2 ppm), yogurt, milk, meats, cognac, beer (4 to 64 ppm), whiskies, cider, sherry, grape wines, rum, cocoa, coffee, tea, filberts, peanuts, popcorn, oats, honey, soybeans, coconut, olive oil (0.02 ppm) and olive.

Использование

Ethyl acetate is used as a solvent for varnishes, lacquers, and nitrocellulose; as anartificial fruit flavor; in cleaning textiles;and in the manufacture of artificial silk andleather, perfumes, and photographic filmsand plates (Merck 1996). Ethyl Acetate is generally used as a solvent in organic reactions. Environmental contaminants; Food contaminants.

Подготовка

Ethyl acetate is made by esterification of acetic acid with ethanol, from acetaldehyde, or by the direct addition of ethylene to acetic acid. BP started a 220,000 tonne/year plant in 2001 to operate the last of these processes, known as AVADA. Ethylene and acetic acid react in the presence of a heteropolyacid catalyst to give ethyl acetate at a claimed high selectivity and 99.97% purity. This is the world’s largest ethyl acetate plant and is motivated by its increasing use as a more “acceptable” solvent than hydrocarbons.
In some countries, where ethanol is expensive or there is surplus acetaldehyde capacity, ethyl acetate is made by a Tishchenko reaction. Sasol in South Africa was said to be investigating such a process in the early 2000s. Ethanol is a solvent for surface coatings, cleaning preparations, and cosmetics. Industrial ethanol is aerobically fermented to white vinegar (dilute acetic acid) of the type used for pickling. Gourmet vinegars—wine vinegar, cider vinegar, and so on, made by fermentation of alcoholic beverages—are also available. Ten percent of industrial ethanol production was used for vinegar in the United States in 2001.

Методы производства

Ethyl acetate can be manufactured by the slow distillation of a mixture of ethanol and acetic acid in the presence of concentrated sulfuric acid. It has also been prepared from ethylene using an aluminum alkoxide catalyst.

Реакции

Ethyl acetate can be hydrolyzed in acidic or basic conditions to regain acetic acid and ethanol. The use of an acid catalyst accelerates the hydrolysis, which is subject to the Fischer equilibrium mentioned above. In the laboratory, and usually for illustrative purposes only, ethyl esters are typically hydrolyzed in a two step process starting with a stoichiometric amount of strong base, such as sodium hydroxide. This reaction gives ethanol and sodium acetate, which is unreactive toward ethanol:
CH₃CO₂C₂H₅ + Na OH → C₂H₅OH + CH₃CO₂Na
The rate constant is 0.111 dm3 / mol.sec at 25 °C.

Использование

как растворитель в производстве лакокрасочных материалов и чернил для печатающих машин. На эти цели расходуется до 30% всего производимого этилацетата;
как растворитель в изготовлении клеевых композиций;
На стадии упаковывания различных товаров гибкими упаковочными материалами - как растворитель чернил при нанесении надписей и изображений трафаретным способом;
как реагент и как реакционная среда в производстве фармацевтических препаратов (метоксазол, рифампицин и т.д.);
как обезжиривающий агент в производстве алюминиевой фольги и тонких алюминиевых листов;
как очищающий и обезжиривающий агент в электронной промышленности;
как растворитель эфиров целлюлозы;
в смеси со спиртом как растворитель в производстве искусственной кожи;
как экстрагирующий агент для различных органических веществ из водных растворов. Благодаря низкой токсичности этилацетат используется в пищевой промышленности, например, для экстрагирования кофеина из кофе.
как желатинизирующее средство при изготовлении взрывчатых веществ;
как компонент фруктовых эссенций.

Общее описание

Ethyl acetate, a carboxylate ester, is bio-friendly organic solvent with wide range of industrial applications. Its synthesis by reactive distillation and by acceptorless dehydrogenative dimerization of ethanol has been explored. Its utility as a less toxic alternative to diethyl ether in the formalin-ether (F-E) sedimentation procedure for intestinal parasites has been investigated. Its ability as an acyl acceptor in the immobilized lipase-mediated preparation of biodiesel from crude vegetable oils has been examined. The complete degradation of ethyl acetate to CO₂ using manganese octahedral molecular sieve (OMS-2) has been investigated.

Реакции воздуха и воды

Highly flammable. Slightly soluble in water. Ethyl acetate is slowly hydrolyzed by moisture.

Профиль реактивности

Ethyl acetate is also sensitive to heat. On prolonged storage, materials containing similar functional groups have formed explosive peroxides. Ethyl acetate may ignite or explode with lithium aluminum hydride. Ethyl acetate may also ignite with potassium tert-butoxide. Ethyl acetate is incompatible with nitrates, strong alkalis and strong acids. Ethyl acetate will attack some forms of plastics, rubber and coatings. Ethyl acetate is incompatible with oxidizers such as hydrogen peroxide, nitric acid, perchloric acid and chromium trioxide. Violent reactions occur with chlorosulfonic acid. . SOCl2 reacts with esters, such as Ethyl acetate, forming toxic SO2 gas and water soluble/toxic acyl chlorides, catalyzed by Fe or Zn (Spagnuolo, C.J. et al. 1992. Chemical and Engineering News 70(22):2.).

Угроза здоровью

The acute toxicity of ethyl acetate is low. Ethyl acetate vapor causes eye, skin, and respiratory tract irritation at concentrations above 400 ppm. Exposure to high concentrations may lead to headache, nausea, blurred vision, central nervous system depression, dizziness, drowsiness, and fatigue. Ingestion of ethyl acetate may cause gastrointestinal irritation and, with larger amounts, central nervous system depression. Eye contact with the liquid can produce temporary irritation and lacrimation. Skin contact produces irritation. Ethyl acetate is regarded as a substance with good warning properties. No chronic systemic effects have been reported in humans, and ethyl acetate has not been shown to be a human carcinogen, reproductive, or developmental toxin

Воспламеняемость и взрывоопасность

Ethyl acetate is a flammable liquid (NFPA rating = 3), and its vapor can travel a considerable distance to an ignition source and "flash back." Ethyl acetate vapor forms explosive mixtures with air at concentrations of 2 to 11.5% (by volume). Hazardous gases produced in ethyl acetate fires include carbon monoxide and carbon dioxide. Carbon dioxide or dry chemical extinguishers should be used for ethyl acetate fires.

хранилище

Защищенным от огня. Отдельно от сильных окислителей, На холоде. Хорошо закрытым.

Химическая реактивность

Reactivity with Water No reaction; Reactivity with Common Materials: No reaction; Stability During Transport: Stable; Neutralizing Agents for Acids and Caustics: Not pertinent; Polymerization: Not pertinent; Inhibitor of Polymerization: Not pertinent.

Фармацевтические приложения

In pharmaceutical preparations, ethyl acetate is primarily used as a solvent, although it has also been used as a flavoring agent. As a solvent, it is included in topical solutions and gels, and in edible printing inks used for tablets.
Ethyl acetate has also been shown to increase the solubility of chlortalidone and to modify the polymorphic crystal forms obtained for piroxicam pivalate, mefenamic acid, and fluconazole,and has been used in the formulation of microspheres. Ethyl acetate has been used as a solvent in the preparation of a liposomal amphotericin B dry powder inhaler formulation.(9) Its use as a chemical enhancer for the transdermal iontophoresis of insulin has been investigated.
In food applications, ethyl acetate is mainly used as a flavoring agent. It is also used in artificial fruit essence and as an extraction solvent in food processing.

Профиль безопасности

Potentially poisonous by ingestion. Toxicity depends upon alcohols in question, generally ethanol with methanol as a denaturant. A flammable liquid and dangerous fire hazard; can react vigorously with oxidzing materials. Moderate explosion hazard. See ETHANOL, METHYL ALCOHOL, and n-PROPYL ALCOHOL.

Безопасность

Ethyl acetate is used in foods, and oral and topical pharmaceutical formulations. It is generally regarded as a relatively nontoxic and nonirritant material when used as an excipient.
However, ethyl acetate may be irritant to mucous membranes, and high concentrations may cause central nervous system depression. Potential symptoms of overexposure include irritation of the eyes, nose, and throat, narcosis, and dermatitis.
Ethyl acetate has not been shown to be a human carcinogen or a reproductive or developmental toxin.
The WHO has set an estimated acceptable daily intake of ethyl acetate at up to 25 mg/kg body-weight.
In the UK, it has been recommended that ethyl acetate be temporarily permitted for use as a solvent in food and that the maximum concentration consumed in food should be set at 1000 ppm.
LD50 (cat, SC): 3.00 g/kg
LD50 (guinea-pig, oral): 5.50 g/kg
LD50 (guinea-pig, SC): 3.00 g/kg
LD50 (mouse, IP): 0.709 g/kg
LD50 (mouse, oral): 4.10 g/kg
LD50 (rabbit, oral): 4.935 g/kg
LD50 (rat, oral): 5.62 g/kg

Возможный контакт

This material is used as a solvent for nitrocellulose and lacquer. It is also used in making dyes,flavoring and perfumery, and in smokeless powder manufacture

Канцерогенность

Ethyl acetate was not mutagenic in bacterial assays; it was not genotoxic in a number of in vivo assays but did cause chromosomal damage in hamster cells in vitro.
Ethyl acetate has a fruity odor detectable at 10ppm.
The 2003 ACGIH threshold limit valuetime- weighted average (TLV-TWA) for ethyl acetate is 400pm (1440mg/m3).

Экологическая судьба

Biological. Heukelekian and Rand (1955) reported a 5-d BOD value of 1.00 g/g which is 54.9% of the ThOD value of 1.82 g/g.
Photolytic. Reported rate constants for the reaction of ethyl acetate and OH radicals in the atmosphere (296 K) and aqueous solution are 1.51 x 10^-12 and 6.60 x 10^-13 cm³/molecule?sec, respectively (Wallington et al., 1988b).
Chemical/Physical. Hydrolyzes in water forming ethanol and acetic acid (Kollig, 1993). The estimated hydrolysis half-life at 25 °C and pH 7 is 2.0 yr (Mabey and Mill, 1978).

Метаболизм

Ethyl acetate is hydrolysed to ethyl alcohol, which is then partly excreted in the expired air and urine. The rest is metabolized, the acetate fraction becoming incor porated in the body pool (Fassett, 1963).

хранилище

Ethyl acetate should be stored in an airtight container, protected from light and at a temperature not exceeding 30°C. Ethyl acetate is slowly decomposed by moisture and becomes acidic; the material can absorb up to 3.3% w/w water.
Ethyl acetate decomposes on heating to produce ethanol and acetic acid, and will emit acrid smoke and irritating fumes. It is flammable and its vapor may travel a considerable distance to an ignition source and cause a ‘flashback’.
The alkaline hydrolysis of ethyl acetate has been shown to be inhibited by polyethylene glycol and by mixed micelle systems.

Перевозки

UN1173 Ethyl acetate, Hazard Class: 3; Labels: 3-Flammable liquid.

Методы очистки

The most common impurities in EtOAc are water, EtOH and acetic acid. These can be removed by washing with aqueous 5% Na2CO3, then with saturated aqueous CaCl2 or NaCl, and drying with K2CO3, CaSO4 or MgSO4. More efficient drying is achieved if the solvent is further dried with P2O5, CaH2 or molecular sieves before distillation. CaO has also been used. Alternatively, ethanol can be converted to ethyl acetate by refluxing with acetic anhydride (ca 1mL per 10mL of ester), the liquid is then fractionally distilled, dried with K2CO3 and redistilled. [Beilstein 2 III 127.]

Несовместимости

Ethyl acetate can react vigorously with strong oxidizers, strong alkalis, strong acids, and nitrates to cause fires or explosions. It also reacts vigorously with chlorosulfonic acid, lithium aluminum hydride, 2-chloromethylfuran, and potassium tert-butoxide.

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. Consult with environmental regulatory agencies for guidance on acceptable disposal practices. Generators of waste containing this contaminant (≧100 kg/ mo) must conform with EPA regulations governing storage, transportation, treatment, and waste disposal.

Регуляторный статус

Included in the FDA Inactive Ingredients Database (oral tablets and sustained-action tablets; topical and transdermal preparations). Included in nonparenteral medicines licensed in the UK (tablets, topical solutions, and gels). Ethyl acetate is also accepted for use in food applications in a number of countries including the UK. Included in the Canadian List of Acceptable Non-medicinal Ingredients.