Chinese synonym: 2- acetone; Acetone; Dimethyl ketone; Dimethyl ketone; Dimethyl ketone; Xylitol; Ethyl ketone; acetone
English name: acetone
English synonym: acetone alcohol; G decolourant; Gram staining No.3; (CH3)2CO； 2- acetone; Acetone; Acetone (German, Dutch, Polish); Acetone oil
Si Nuo. : 67-64- 1
Molecular formula: C3H6O
Molecular weight: 58.08
EINECSno。 : 200-662-2
Related categories: rodenticide and its intermediates; Solvents and cosolvents; Food processing AIDS; food additives
Acetone property
Melting point -94 degrees Celsius (liter. )
Boiling point 56 degrees Celsius 760 mm Hg (liter. )
The density at 25℃ is 0.79 1 g/ml (liter. )
Vapor density 2 (relative to air)
Steam pressure 184 mm Hg (20℃)
Refractive index n20/D 1.359 (liter. )
Federal Emergency Management Agency 3326
Flash point 1 Fahrenheit.
Storage conditions at room temperature
water-soluble
Merck 14.66
BRN 63580
CAS database 67-64- 1 (CAS database reference)
NIST chemical information acetone (67-64- 1)
EPA chemical information 2- acetone (67-64- 1
Application and synthetic method of acetone
Overview acetone, also known as dimethyl ketone, dimethyl ketone, dimethyl ketone or acetophenone, xylene, is the simplest ketone in saturated fatty ketone series. Melting point -95℃, boiling point 56℃, density: specific gravity 0.788 at 25℃, colorless flammable liquid with special smell. It is colorless and transparent liquid at room temperature, volatile, flammable and fragrant. It is miscible with water, methanol, ethanol, ether, chloroform and pyridine, and can dissolve oil, fat, resin and rubber, as well as cellulose acetate and cellulose nitrate. It is an important solvent. Acetone has no special toxicity to human body, but it can cause symptoms such as headache and bronchitis after inhalation. If inhaled in large quantities, you may lose consciousness. Mainly used for degreasing, dehydration, fixation and so on in daily life. It is an important test object in blood and urine. Some cancer patients have unusually high levels of acetone in their urine. The concentration of acetone in blood and urine of people who lose weight through low-carbohydrate food therapy is also extremely high. Acetone exists in a free state in nature, mainly in the essential oils of the plant kingdom, such as tea oil, turpentine, citrus essential oil and so on. Human urine and blood, animal urine, marine animal tissues and body fluids all contain a small amount of acetone. The content of acetone in urine of diabetic patients is abnormally high. The mixture of steam and air can form an explosive mixture, and the explosion limit is 2.55% ~ 12.8% (by volume). The carbonyl group of acetone can react with many nucleophiles, such as catalytic hydrogenation to isopropanol and reduction to pinacol; React with ammonia derivatives, hydrocyanic acid, alkynes, organometallic compounds, etc. Acetone can also react with α-hydrogen, such as substitution reaction with halogen and aldol condensation reaction with itself or other compounds.
Molecular structure in acetone molecule, C atom on carbonyl group is bonded by sp2 hybrid orbital, and C atom on methyl group is bonded by sp3 hybrid orbital.
Limit parameter spontaneous combustion point: 465℃ Explosion limit: 2.6%~ 12.8% Maximum explosion pressure: 87.3 N/cm2 Most flammable concentration: 4.5 Maximum explosion pressure concentration: 6.3% Minimum ignition energy: 1. 15 mJ (concentration: 4.97
Purification and water removal methods Ordinary acetone often contains a small amount of water and reducing impurities, such as methanol and acetaldehyde. The purification method comprises the following steps:
(1) Add 2.5g potassium permanganate to 250mL acetone and reflux. If the purple color of potassium permanganate disappears soon, add a small amount of potassium permanganate to continue refluxing until the purple color does not fade. Then acetone is distilled, dried with anhydrous potassium carbonate or anhydrous calcium sulfate, filtered and distilled, and the fraction at 55-56.5 DEG C is collected. When using this method to purify acetone, we must pay attention to the fact that there are not too many reducing substances in acetone, otherwise it will consume too much potassium permanganate and acetone and increase the treatment time. ⑵ Put 100mL acetone in a separatory funnel, first add 4ml 10% silver nitrate solution, then add 3.6ml 1mol/L sodium hydroxide solution, shake 10min, separate the acetone layer, and then add anhydrous potassium sulfate or anhydrous calcium sulfate to dry. Finally, distill and collect the fraction at 55-56.5℃ ... This method is faster than the method (1), but silver nitrate is more expensive, so it should only be used for a small amount of purification.
As an important organic raw material in chemical industry, man-made fiber, medicine, paint, plastics, plexiglass, cosmetics and other industries, it is an excellent organic solvent, which can dissolve many organic products such as resin, acetate fiber and acetylene. It is also a solvent for manufacturing nitrocellulose. In industry, acetone is mainly used as a solvent for explosives, plastics, rubber, fibers, tanning, grease, paint and other industries. Acetone can also be used as an important raw material for the synthesis of ketene, acetic anhydride, iodoform, polyisoprene rubber, methacrylic acid, methyl ester, chloroform, epoxy resin and other substances. In the manufacturing of precision copper tubes, acetone is often used to wipe the black ink on copper tubes.
Examples of common uses:
Solvent: For example, acetone is the main (or only) component in polishing water for removing nail polish. It is also a common cleaning solvent in the laboratory.
Reagent: Acetone is a C3 synthon in synthesis, which can be used in organic synthesis. In addition, acetone is also the precursor of protecting group, which protects 1, 2- diol or 1, 3- diol by generating ketals.
Coolant: A mixture of acetone and dry ice can be used as coolant (Celsius: -50℃).
Preparation methods The production methods of acetone mainly include isopropanol method, cumene method, fermentation method, acetylene hydration method and direct oxidation method of propylene. At present, the industrial production of acetone in the world is mainly cumene method. Two-thirds of acetone in the world is a by-product of phenol preparation and one of the products of cumene oxidation. At present, the main patent manufacturers of this technology are Kellogg Brown &; Root Company, Mitsui Chemical Company and UOP Company.
Shounuo Company developed a technology to produce phenol by oxidizing benzene with nitrogen oxides, but last year it cancelled its plan to build a factory with this technology because the gross profit level was too low. Recently, Japanese researchers have also developed a one-step process for producing phenol and acetone from benzene with Europium-titanium catalyst.
Dry distillation method: Before the invention of cumene method, early acetone was mostly made by dry distillation of calcium acetate.
Fermentation: Acetone can be obtained by fermentation with butanol yeast. This method was invented by chaim weizmann during World War I, but it was soon abandoned because of the extremely low output.
Oxidative synthesis method of cumene: cumene, a product of petroleum industry, is oxidized by air under the catalysis of sulfuric acid and rearranged into by-products acetone and phenol. This method produces little waste, which is called "kill two birds with one stone".
Toxic and harmful acetone mainly inhibits and anesthetizes the central nervous system, and high concentration exposure may cause damage to the liver, kidney and pancreas of individuals. Because of its low toxicity and rapid metabolism and detoxification, acute poisoning rarely occurs under production conditions. Acute poisoning can cause vomiting, shortness of breath, convulsions and even coma. After oral administration, the lips and pharynx are burning, and after several hours of incubation, dry mouth, vomiting, lethargy, moderate acidosis and ketosis may occur, and even temporary disturbance of consciousness may occur. The long-term damage of acetone to human body is manifested as eye irritation symptoms such as tears, photophobia and corneal epithelial infiltration, as well as dizziness, burning sensation, throat irritation and cough.
Metabolism: After being absorbed by the lungs, gastrointestinal tract and skin, acetone is easily absorbed into the blood and quickly distributed throughout the body due to its strong water solubility. Its excretion depends on the dose. In large doses, it mainly passes through the lungs and kidneys, and a very small amount is discharged through the skin. In small doses, most of them are oxidized into carbon dioxide and discharged. The biological half-life of acetone in blood is 5.3 h in rats, 1 1 h in dogs and 3 h in humans. The metabolism of acetone in human body is mostly that the intermediate of tricarboxylic acid cycle is decomposed into acetoacetic acid and converted into glycogen.
1. Inhalation: the concentration below 500ppm has no effect; 500 ~ 1000ppm will irritate the nose and throat; At 1000 ppm, it will cause headache and dizziness. Dizziness, drunkenness, lethargy, nausea and vomiting may occur at 2000 ~ 10000 ppm, and high concentration may lead to unconsciousness, coma and death.
2. Eye contact: 500ppm concentration will cause irritation, and 1000ppm will cause mild and temporary irritation. Liquid can produce toxic stimulation.
3, skin irritation: liquid will have mild irritation, and the risk caused by complete skin absorption is very small.
4, oral: irritating to the throat and stomach, a large number of doses will produce the same symptoms as inhalation.
5. Skin contact can lead to dryness, redness and chapping. Inhaling steam with the concentration of 1000ppm for 3 hours every day will stimulate the nasal cavity of workers who have been working for 7 ~ 15 years, making them dizzy and weak. High concentration of steam will affect the function of kidney and liver.
First aid and protective fire fighting:
Highly flammable, with serious fire hazard, it belongs to Class A fire hazard substances. At room temperature, steam and air will form an explosive mixture.
Use dry powder, anti-solvent foam extinguishing agent, halogen extinguishing agent or carbon dioxide to extinguish the fire. Use water to cool containers exposed to fire and disperse acetone vapor.
Personal protection:
1. Inhalation: If the vapor concentration is unknown or exceeds the exposure limit, wear a suitable respirator.
2. Skin: gloves, work clothes and work shoes should be used when necessary, and butyl rubber should be used as the material. There should be safe shower and eye washing equipment in the direct workplace.
3. Eyes: If necessary, wear chemical splash-proof glasses and a mask.
First aid:
1. Inhalation: Leave the acetone source or move the patient to fresh air. If breathing stops, artificial respiration should be performed.
2. Eye contact: Open the eyelids and rinse the affected eyes with lukewarm and slowly flowing water for about 10 minutes.
3. Skin contact: Wash the affected area with warm water and slowly flowing water for at least 10 minute.
4, oral: rinse your mouth with water, do not induce vomiting, give the patient about 250ml of water.
5. All patients should seek medical treatment.
Content analysis: accurately weigh about 65438 0 g sample into a flask containing 20ml of water, and add water to 65438±0000ml. Take this solution 10ml, put it in a glass stopper flask for 5min, add 25 ml sodium hydroxide test solution (TS-224) and let it stand for 5min. Add 25ml 0. 1mol/L iodine solution, plug it tightly, place it in a cold dark place 10min, and add 30ml 1mol/L sulfuric acid. Titrate the remaining iodine with 0. 1mol/L sodium thiosulfate, and use starch test solution (TS-235) as indicator. Do the same blank test according to the sample size and make necessary corrections. 0. 1 mol/L iodine is equivalent to 0.9675mg C3H6O per milliliter.
toxicity
ADI GMP is limited (FAO/WHO, 200 1).
LD 503000mg/kg (mice, oral).
The acute lethal dose to humans is 50 ml/person.
limitations on use
FDA 173.2 10 (2000): The limit of perfume oil resin is 30mg/kg.
FEMA (mg,/kg): soft drinks 5; Cold drink 5; Candy 8; Baked food 8; Pudding class 5; Spread food.
Maximum allowable dosage and maximum allowable residue of food additive Chinese name of standard additive Chinese name of food in which the additive is allowed to be used Functional maximum allowable dosage (g/kg) Maximum allowable residue (g/kg)
The components of acetone food flavor used to prepare flavor shall not exceed the maximum allowable dosage and maximum allowable residue in GB 2760.
Acetone food processing AIDS for food industry/processing AIDS for food industry should generally leave the factory before making the final product, unless there are regulations on residues in food.