Ether, also known as Ether, diethyl ether orEthoxyethane, is an ether organic compound, with the chemical formulaCfourHtenOor（CtwoHfive）twoO, sometimes abbreviated asEttwoOIt is a colorless, highly volatile, sweet ("flowing smell"), highly flammable liquid, usually used as a solvent in the laboratory, and as the starting liquid of some engines.Before nonflammable drugs such as halothane were developed, they were often used as general anesthetics in medicine.The gunpowder industry is used to manufacture smokeless gunpowder.
In the 19th century, Morton, an American dentist, could not bear to have his teeth extracted without anesthetic in the medical practice. He made numerous explorations and researches to find a painless method for tooth extraction. Later, his friends suggested that he could use ether for experiments. Later, he covered his dog's mouth and nose with a sponge soaked in ether and inhaled it,After a few seconds, the dog became weak and lay down and lost consciousness. This experiment made him very satisfied. After that, on October 16, 1846, through cooperation with the surgeon, they put ether into an inhalable device for the patient to inhale, and successfully performed a neck tumor resection operation without pain and consciousness,Since then, ether anesthesia has become an indispensable drug in operating rooms of hospitals all over the world.The invention of anesthesia, especially ether anesthesia, has epoch-making significance in promoting the healthy development of human beings and the progress of human social civilization. It has opened a new chapter in the history of modern medicine.
So far, the history of human surgery has been divided into two periods, and Morton ranked 37th in McHart's "100 Celebrities Who Influence the Short Range of Human History".On his epitaph, it was written that "before him, surgery was a form of torture; after him, science overcame pain".Since a doctor named Long also successfully performed ether anesthesia on March 30, 1842, before him, the US government designated March 30 as the National Physicians' Day.
Physical property data
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1. Character: colorless transparent liquid, with aromatic smell, very volatile.
2. Melting point (℃): - 116.2
3. Boiling point (℃): 34.6
4. Relative density (water=1): 0.71 (20 ℃)
5. Relative vapor density (air=1): 2.56
6. Saturated vapor pressure (kPa): 58.92 (20 ℃)
7. Combustion heat (kJ/mol): - 2748.4
8. Critical temperature (℃): 192.7
9. Critical pressure (MPa): 3.61
10. Octanol/water partition coefficient: 0.89
11. Flash point (℃): - 45 (CC)
12. Ignition temperature (℃): 160~180
13. Upper explosive limit (%): 49.0
14. Lower explosive limit (%): 1.7
15. Solubility: slightly soluble in water, soluble in ethanol, benzene, chloroform, solvent naphtha and other organic solvents.
1. The chemical property of ether is stable, close to the property of saturated hydrocarbon, quite stable to alkali, oxidant and reducing agent, and does not react with metal sodium at room temperature.However, strong acids can break the ether bond, for example, concentrated hydroiodic acid can quantitatively generate iodoethane, so it can be used to quantitatively determine the content of ethoxyl in compounds.The reaction of ether with anhydrous nitric acid or mixture of concentrated sulfuric acid and concentrated nitric acid will cause violent explosion.Ether is oxidized with anhydrous chromic acid and nitric acid to form acetic acid.When ether vapor and air pass through copper platinum black powder heated to 100 ℃, acetaldehyde and formaldehyde are generated.The oxygen atom on the ether bond has an unpublished electron pair, which is used as a Lewis base to combine with other atoms or groups (Lewis acid) to form an item sheep salt.This kind of sheep salt can only be generated under the action of concentrated hydrochloric acid and sulfuric acid, and can only exist stably under concentrated acid. It will be hydrolyzed when it meets water[3]。Ether can also form addition products with boron trifluoride, aluminum trichloride, Grignard reagent, beryllium chloride, hydrogen bromide, titanium tetrachloride, and antimony and zinc halides.Ether reacts with halogen to form various halogen derivatives.When ether contacts with air, explosive peroxides are gradually formed.Explosion limit 1.85%~36.5% (volume)
2. Ether has excellent insulation. When it vibrates in the air or is filtered with silk, static electricity due to friction may also cause natural fire.It shall not be mixed with gunpowder, poisons, radioactive substances, oxidizing substances, organic peroxides, etc.Ether can form explosive peroxides when exposed to light or in the air for a long time.It is not suitable to evaporate to dryness during distillation, so as to avoid explosion of peroxide that is not removed completely.Antioxidants should be added to prevent the formation of peroxides.The most effective antioxidant is sodium amalgam.Asbestos soaked in alkaline pyrogallol solution is also effective in ether.1-naphthol is used as antioxidant in industry.In the laboratory, iron filings, copper wires, copper filings or solid potassium hydroxide are often added to ether and stored in brown bottles.Non corrosive to metal.
3. Ether is a toxic substance. Long term breathing of ether gas can stimulate the respiratory organs, inflame, weaken memory, and cause depression.Drink 30~60mL to kill.Poisons are produced when burning, which can make people faint or even die.In the initial stage of acute ether poisoning, it presents an excited state, and then causes anesthesia, vomiting, andCyanosisThe body temperature drops, the limbs get cold, sometimes the breathing stops suddenly, the pulse is weak, and the pupils dilate, but it will not die, so it is less dangerous to use as an anesthetic.Severe acute poisoning can cause vomiting, cough, weakness, and often complicated with nephritis, bronchitis and pneumonia.The poisoned person should leave the site and move to a fresh air place. Pay attention to the patient's heat preservation, oxygen supply, and medical treatment.The production equipment shall be strictly sealed and the site shall be well ventilated.Operators shall wear protective equipment and have regular physical examination.The maximum allowable concentration in the air is 1200mg/L.Ether is a Class I inflammable, with an explosion limit of 1.85~36.5% (- 45~13 ℃). It is very easy to burn and will explode in case of open fire. It can generate explosive peroxides and explode in the presence of perchloric acid or chlorine.It can self expand in hot weather or strong sunlight, which is more dangerous than gasoline.It is toxic when burning and can make people unconscious.
6. Conditions to avoid contact: heating, air contact
7. Polymerization hazard: no polymerization
synthetic method
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It is prepared by heating ethanol and concentrated sulfuric acid to 130-140 ℃.
Preparation steps: add 50ml of 95% ethanol, 50ml of concentrated sulfuric acid, several zeolites and heat to 140 ℃ into the reaction bottle with thermometer, drip funnel (the end of thermometer and drip funnel is immersed below the liquid level, 0.5~1cm from the bottom of the bottle) and distillation device (the receiving bottle is cooled with ice water bath, and the lead pipe is connected to the sewer or outdoor with a rubber tube).Then drop 100ml of ethanol while reacting and distilling to obtain crude ether.Use 5% NaOH, saturated NaCl and saturated CaCl respectivelytwoWash the solution thoroughly.Finally, anhydrous CaCl is used for ether layertwoDry and filter to obtain clear ether for distillation to obtain refined ether[4]。
purpose
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one
Anesthetic: As a powerful general anesthetic, ether has been widely used in medical surgery and pain management.However, over time, due to its instability and potential toxicity, the clinical use of ether has been greatly reduced.
two
Laboratory solvent: Ether is widely used as a solvent in the laboratory, especially in organic synthesis.It has good solubility and can be used to dissolve many organic substances, such as fats, resins and oils.
three
Chemical synthesis: Ether plays an important role in organic chemical synthesis.It can be used as reactant, solvent or extractant to promote various organic reactions, such as esterification, etherification and carbonylation.It is particularly important as a solvent for the production of cellulose plastics (such as cellulose acetate).
four
Spice and essence industry: Due to its pleasant smell, ether is used in the spice and essence industry.It can be used as an additive in some foods and drinks to add aroma.
five
Cleaning agent: ether has good solubility and volatility and can be used as cleaning agent, such as cleaning metal surface, dissolving grease and removing paint
It should be noted that ether has the characteristics of flammability and volatility during use. Safety measures should be taken to avoid exposure to open flame and high temperature environment and ensure adequate ventilation.[5]
Safety measures
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Leakage treatment
Evacuate the personnel in the leakage contaminated area to a safe area quickly, isolate them, and strictly restrict access.Cut off the ignition source.It is recommended that emergency personnel wear self-contained positive pressure respirators and anti-static work clothes.Cut off the leakage source as much as possible.Prevent from flowing into restricted spaces such as sewers and flood discharge ditches.
Small scale leakage can be absorbed and removed with absorbent (such as sand, vermiculite or chemical absorbent).For large-scale leakage, seek the assistance of professional chemical removal team.
First aid treatment
Emergency evacuation: quickly transfer the patient to a well ventilated place, away from the source of ether leakage or harmful gas environment.Ensure the safety of yourself and others.
Respiratory management: check whether the patient's respiratory tract is unobstructed.If necessary, take appropriate measures to ensure that the patient's respiratory tract is unblocked, such as lateral position or head back.
Respiratory support: If the patient has difficulty breathing or stops breathing, immediately carry out cardiopulmonary resuscitation (CPR).Call the emergency number and follow the instructions of relevant institutions or professionals.
Medical assistance: seek medical assistance.Call the local emergency number or send the patient to the nearest medical institution.Inform the medical staff of the incident and suspected ether poisoning.
Storage notes
1. Packed in iron drums, 240L each.It should be stored in a cool, dry and ventilated basement, and the room temperature should be lower than 25 ℃.During storage and transportation, avoid violent vibration, impact and exposure. It should be isolated from oxidants. In hot seasons, it should not be transported in the hot sun.The package shall be marked with "Dangerous Goods".
2. Precautions for storage.Generally, the commodity is added with stabilizer.Store in a cool and ventilated warehouse.Keep away from kindling and heat sources.The warehouse temperature should not exceed 29 ℃.The package shall be sealed and shall not contact with air.It shall be stored separately from oxidants, and mixed storage is strictly prohibited.It should not be stored in large quantities or for a long time.Explosion proof lighting and ventilation facilities shall be adopted.It is prohibited to use mechanical equipment and tools that are easy to generate sparks.The storage area shall be equipped with leakage emergency treatment equipment and appropriate materials.
Fire fighting measures
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Hazard characteristics: Its vapor and air can form an explosive mixture, which is very easy to burn and explode in case of open fire and high heat.It can react strongly with oxidants.It can form explosive peroxides after being stored in air for a long time.In a fire, heated containers may explode.Its vapor is heavier than air, and can spread to a considerable distance at a lower place. It will ignite and recoil when encountering an ignition source.
Extinguishing method: Move the container from the fire site to an open place as far as possible.Spray water to keep the fire site container cool until the fire is extinguished.If the container in the fire site has changed color or sounds from the safety relief device, it must be evacuated immediately.
Extinguishing agent: insoluble foam, carbon dioxide, dry powder, sand.Fire extinguishing with water is invalid.
security information
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Dangerous transport code: UN 1155 3/PG 1
Dangerous goods mark:
Safety signs: S9, S16, S29, S33
Hazard signs: R12, R19, R22, R66, R67
Safety terminology
S9：Keep container in a well-ventilated place.
Keep the container in a well ventilated place.
S16：Keep away from sources of ignition - No smoking.
Keep away from ignition sources and no smoking.
S29：Do not empty into drains.
Do not discharge into the sewer.
S33：Take precautionary measures against static discharges.
Take precautions against static electricity.
Risk terminology
R12：Extremely flammable.
Extremely flammable.
R19：May form explosive peroxides.
Explosive peroxides may be generated.
R22：Harmful if swallowed.
It is harmful if swallowed.
R66：Repeated exposure may cause skin dryness or cracking.
