I. Introduction
Acetone is a colorless liquid with a pleasant smell (spicy and sweet). Changeable. It is miscible with water, ethanol, N, N- dimethylformamide, chloroform, ether and most oils. The relative density d25 is 0.7845. Melting point -94.7℃. The boiling point is 56.05℃. Refractive index (n20D) 1.3588. Flash point -20℃. Flammable. The median lethal dose (oral) of rats was 10.7ml/kg. Irritating.
Second, the physical properties
Colorless, transparent and easily flowing liquid, with aromatic smell and volatility.
Melting point (℃):-94.6
Relative density (water = 1): 0.80.
Boiling point (℃): 56.5
Relative steam density (air = 1): 2.00.
Molecular formula: C3H6O
Molecular weight: 58.08
Saturated vapor pressure (kpa): 53.32 (39.5℃)
Combustion heat (kJ/mol): 1788.7
Critical temperature (℃): 235.5
Critical pressure (MPa): 4.72
Logarithmic value of octanol/water partition coefficient: -0.24
Flash point (℃):-20
Upper explosion limit% (v/v): 13.0
Ignition temperature (℃): 465
Lower explosive limit% (volume/volume): 2.5
Solubility: miscible with water, miscible with most organic solvents such as ethanol, ether, chloroform, oil and hydrocarbons.
Third, chemical properties.
The simplest ketone in acetone saturated fatty ketone series. It has a special smell and can dissolve cellulose acetate and cellulose nitrate. 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 mixture of steam and air can form an explosive mixture, and the explosion limit is 2.55% ~ 12.8% (by volume). Vapor pressure (kPa): 53.32 (39.5℃). Combustion heat (kj/mol): 1788.7. Octanol-water partition coefficient (kow):-0.24. It is miscible with water and most organic solvents, such as ethanol, ether, chloroform, oil, propanol and hydrocarbons.
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.
Fourth, the preparation method
The main production methods of acetone are isopropanol, cumene, fermentation, acetylene hydration and direct oxidation of propylene. The industrial production of acetone is mainly based on cumene method. Two-thirds of acetone in the world is a by-product of phenol preparation and one of the products of cumene oxidation. The main patent manufacturer of this technology is 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.
1, fermentation method
Acetone can be obtained by fermentation with butanol yeast.
2, cumene oxidation synthesis method
Cumene, a product of petroleum industry, was oxidized by air under the catalysis of sulfuric acid and rearranged into acetone, a by-product of phenol. This method produces little waste, which is called "kill two birds with one stone".
Verb (abbreviation of verb) is used.
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:
1. solvent: for example, the main (or only) component in polishing water for removing nail polish is acetone. It is also a common cleaning solvent in the laboratory.
2. 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.
3. Coolant: A mixture of acetone and dry ice can be used as coolant (Celsius: -50℃).
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 used to be made from wood or calcium acetate by dry distillation; Later, it was prepared by pyrolysis of ethanol, air oxidation of isopropanol or dehydrogenation of isopropanol. Recently, acetone was prepared from propylene by Wagner oxidation or direct water oxidation. Acetone can also be prepared by starch fermentation. Acetone can be used as raw material for man-made fiber, plexiglass, paint and cosmetics. It is also a good solvent, which can dissolve many organic products, such as resin, cellulose acetate, acetylene and so on. It is also a solvent for manufacturing nitrocellulose.
Security of intransitive verbs
(1) hazard
Its steam and air can form an explosive mixture, which is easy to burn and explode in case of open flame and high heat. Can react strongly with oxidant. Its vapor is heavier than air, and it can spread to a considerable distance at a lower place, and it will catch fire when it meets a fire source. In case of high heat, the internal pressure of the container rises, which is in danger of rupture and explosion.
(2), emergency disposal
1, skin contact: take off contaminated clothes and rinse the skin thoroughly with soapy water and clean water.
2. Eye contact: Lift the eyelid and wash it with running water or normal saline. See a doctor.
3. Inhalation: leave the scene quickly and go to a place with fresh air. Keep the respiratory tract unobstructed. If you have difficulty breathing, give oxygen. If breathing stops, give artificial respiration immediately. See a doctor.
4, eating: drink enough warm water to induce vomiting. See a doctor.
5. Respiratory protection: When the concentration in the air exceeds the standard, wear a filter gas mask (half mask).
6, eye protection: generally do not need special protection, high-concentration contact can wear protective glasses.
7. Physical protection: wear anti-static work clothes.
8. Hand protection: Wear rubber oil-resistant gloves.
9. Other protection: Smoking is strictly prohibited at the work site. Pay attention to personal hygiene. Avoid long-term repeated contact.
10. Emergency treatment of leakage: evacuate the personnel in the leaked contaminated area to a safe area quickly, isolate them and strictly restrict access. Cut off the fire. It is recommended that emergency personnel wear self-contained positive pressure breathing apparatus and anti-static work clothes. Cut off the leakage source as much as possible. Prevent it from flowing into confined spaces such as sewers and flood discharge ditches. Small amount of leakage: adsorbed or absorbed by sand or other nonflammable substances. It can also be washed with plenty of water, diluted and put into the wastewater system. A large number of leaks: damming or digging holes to contain them. Cover with foam to reduce steam disaster. Use explosion-proof pump to transfer it to tank car or special collector, and recycle it or transport it to waste disposal site for treatment.
1 1. Harmful combustion products: carbon monoxide and carbon dioxide.
12. Fire extinguishing method: move the container from the fire to the place as open as possible. Spray water to keep the burning container cool until the fire goes out. If the container in the fire changes color or the safety pressure relief device sounds, it must be evacuated immediately. Extinguishing agent: soluble foam, carbon dioxide, dry powder, sand. Fire extinguishing with water is ineffective. [ 1]
(3), toxicity data
1, acute toxicity: LD50: 5800 mg/kg (by mouth in rats); 20000 mg/kg (rabbit skin); Inhalation 12000 ppm×4 h, minimum toxic concentration. 200 ml orally, coma, 12 h recovery. People can produce mucosal irritation at the concentration of 300 ppm; Generally, it can still be tolerated when the concentration is as high as 500 ppm; At 2000 ppm, it can produce slight and obvious anesthetic effect; Inhalation of 9300 ppm can not be tolerated for more than 5 min due to obvious laryngeal irritation. Adults who take 20 ml by mistake have no effect, but 200 ml can cause coma (usually 12 h later).
2. Subacute and chronic toxicity: experimental animal poisoning is characterized by salivation, tears, dyskinesia, convulsions and convulsions. Stimulation of nasal mucosa can cause temporary respiratory arrest. The kidneys of poisoned animals may be damaged, such as severe poisoning at a high concentration of 24. 14 ~ 120.7 g/m3, slight degeneration of kidneys, slight necrosis of renal tubular epithelial cells, fatty infiltration of collecting duct and urinary protein; Pulmonary congestion may also occur. Scleral dehydration can occur after contact with rabbit eyes, which leads to colloidal flocculent changes and eventually blindness.
3. Metabolism: After acetone is absorbed through the lungs, gastrointestinal tract and skin, it 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.
4. Poisoning mechanism: Its toxicity mainly affects the anesthetic effect of the central nervous system and mucosal stimulation.
5, irritation: rabbit eyes: 3950 μg, severe irritation. Rabbit percutaneous open stimulation test: 395 mg, mild stimulation.
6. Mutagenicity: Cytogenetic analysis: Saccharomyces cerevisiae 200 mmol/tube.
7. Environmental toxicology: When the water content is higher than 4 g/L, sludge digestion is inhibited. When the water content is 840 mg/L, the nitrification of ammonia nitrogen by activated sludge is reduced by 75%.
(4) Emergency medical treatment
1, diagnosis point:
Acute poisoning is mainly manifested in different degrees of anesthesia.
(1), fatigue, nausea, headache, dizziness, irritability, etc. Severe convulsions and even coma.
(2) Dry mouth, vomiting, drowsiness and ketoacidosis appeared in the incubation period of several hours after oral administration. Adults taking 20 ml by mistake has no effect, but 200 ml will cause temporary disturbance of consciousness. No deaths were reported.
(3) The irritation symptoms of acetone to eyes are tears, photophobia and corneal epithelial infiltration.
(4) There is acetone in the urine, and the hemogram has no obvious change.
2, processing principle:
No specific antidote, symptomatic support treatment. Sodium lactate and sodium bicarbonate are used in patients with acidosis.