Propadiene is an organic compound with chemical formula CthreeHfourIt is a colorless gas at normal temperature and pressure, slightly sweet, tautomeric with acetylene, and has a large equilibrium constant. It is an important basic organic chemical raw material.
Chinese name
Propadiene
Foreign name
allene
chemical formula
CthreeHfour
molecular weight
forty point zero six four
CAS login number
463-49-0
EINECS login number
207-335-3
Melting point
-136 ℃
Boiling point
-34.5 ℃
Water solubility
Insoluble
Appearance
Colourless gas
Application
Used as an organic intermediate
Security description
S9；S16；S33
Hazard symbol
F+
Hazard description
R12
MDL No
MFCD00008566
RTECS No
BA0400000
BRN No
one million seven hundred and thirty thousand seven hundred and seventy-four
PubChem No
twenty-four million eight hundred and fifty-seven thousand seven hundred and forty-nine
Solubility: insoluble in water, slightly soluble in ethanol, soluble in benzene, petroleum ether, easily soluble in ether
chemical property
The accumulated diolefins of propadiene are structurally unstable, and intramolecular hydrogen transfer will occur to become propargyl:
Propadiene
Its equilibrium constantKeqIt is 0.22 (270 ° C) or 0.1 (5 ° C). Its mixture with acetylene is called MAPP gas, which is a common industrial gas and is often used for welding.
Calculate chemical data
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Reference value for drainage parameter calculation (XlogP): 0.8
Number of hydrogen bond donors: 0
Number of hydrogen bond receptors: 0
Number of rotatable chemical bonds: 0
Number of tautomers: 1
Topological molecular polar surface area: 0
Number of heavy atoms: 3
Surface charge: 0
Complexity: 15.5
Number of isotope atoms: 0
Determine the number of atomic structure centers: 0
Number of uncertain atomic structure centers: 0
Determine the number of chemical bond structure centers: 0
Number of uncertain chemical bond structure centers: 0
Number of covalent bond units: 1
First aid measures
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Skin contact: If there is frostbite, seek medical treatment.
Eye contact: If there is frostbite, seek medical treatment.
Inhalation: quickly leave the site to a place with fresh air.Keep the respiratory tract unobstructed.If breathing is difficult, give oxygen.If breathing stops, perform artificial respiration immediately.Get medical attention.
Fire fighting measures
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Hazard characteristics: flammable, can form explosive mixture when mixed with air.In case of heat source and open fire, there is danger of combustion and explosion.It is a very active substance and easy to polymerize.Explosive decomposition may occur at 200kPa atmospheric pressure.The gas 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: cut off the gas source.If the air source cannot be cut off, it is not allowed to extinguish the flame at the leakage.Spray water to cool the container, and move the container from the fire site to an open place if possible.
Evacuate the personnel in the leakage contaminated area to the windward place 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.Cover the sewer and other places near the leakage point with industrial coating or adsorption/absorbent to prevent gas from entering.Reasonable ventilation to accelerate diffusion.Dilute with spray water.Build a dike or dig a pit to collect a large amount of wastewater generated.If possible, use pipes to lead to the furnace and burn it in the depression.Leaking containers shall be properly treated, repaired and inspected before reuse.
Protective measures
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Engineering control: the production process is closed and fully ventilated.
Respiratory system protection: generally, no special protection is required, and self-priming filter gas mask (half mask) can be worn in case of high concentration contact.
Eye protection: wear chemical safety goggles.
Body protection: Wear anti-static work clothes.
Hand protection: wear general operation protective gloves.
Other protection: smoking is strictly prohibited at the work site.Avoid long-term repeated contact.[2]
matters needing attention
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Precautions for operation: closed operation, full ventilation.Operators must be specially trained and strictly abide by the operating procedures.It is recommended that operators wear self-priming filter type gas mask (half mask), chemical safety goggles and anti-static work clothes.Keep away from kindling and heat sources, and smoking is strictly prohibited in the workplace.Use explosion-proof ventilation systems and equipment.Prevent gas leakage into the air of the workplace.Avoid contact with oxidants, alkalis, heavy metal powders, mercury and its compounds.During transmission, the cylinder and container must be grounded and bridged to prevent static electricity.Load and unload gently during transportation to prevent damage to packaging and containers.Fire fighting equipment and leakage emergency treatment equipment of corresponding types and quantities shall be provided.
Precautions for storage: stored in a cool and ventilated special warehouse for flammable gas.The warehouse temperature should not exceed 30 ℃.Keep away from kindling and heat sources.It should be stored separately from oxidants, alkalis, heavy metal powders, mercury and its compounds, and should not be mixed.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.[1]
Transportation precautions: the railway transportation must be reported to the railway bureau for trial operation, and the trial operation period is two years.After the test run, a test run report shall be written and submitted to the Ministry of Railways to officially announce the transportation conditions.When steel cylinders are used for transportation, safety helmets on steel cylinders must be worn.Cylinders are generally placed horizontally, and the mouth of the cylinder should be in the same direction, not crossed;The height shall not exceed the protective fence of the vehicle, and shall be firmly clamped with triangular wood pad to prevent rolling.The transport vehicles shall be equipped with corresponding types and quantities of fire-fighting equipment.The exhaust pipe of the vehicle transporting this article must be equipped with a fire retardant device. It is prohibited to use mechanical equipment and tools that are easy to generate sparks for loading and unloading.It is strictly prohibited to mix with oxidants, alkalis, heavy metal powders, mercury and its compounds, edible chemicals, etc.Transport in the morning and evening in summer to prevent sunlight exposure.Keep away from kindling and heat sources during stopover.Road transportation shall be carried out according to the specified route, and it is forbidden to stay in residential areas and densely populated areas.It is forbidden to slip during railway transportation.[2]
