Learn about the utility of acetic anhydride in various industries in one article

[Alias]Acetic anhydride, acetic anhydride.

［Molecular Formula］C4H6O3

[Properties]It is the condensation product of two acetic acid molecules losing one water molecule:

Acetic anhydride is a colorless, volatile liquid with a strong pungent odor and corrosiveness. The relative density is 1.0820, the boiling point is 138.63℃, the melting point is -74.13℃, the viscosity is 0.91mpa·s (20℃), the refractive index is 1.390 (20℃), and the autoignition point is 388.9℃. Soluble in benzene, ethanol, chloroform and ether. It decomposes when in contact with water to produce acetic acid.

[Use of acetic anhydride] is an important organic chemical raw material. It is an acetylating agent used in the manufacture of cellulose acetate and is used pharmaceutically to manufacture aspirin, synmycin, dibazole and other drugs. It is also used in the manufacture of synthetic dyes, spices, pesticides, etc., and can also be used as dehydrating agent, polymerization initiator, etc.

[Brief preparation method]

① Use acetic acid as raw material, catalytically crack it under high temperature and vacuum to generate ketene, and then absorb it with acetic acid to prepare acetic anhydride.

② Acetaldehyde is oxidized to generate peracetic acid, and then peracetic acid and acetaldehyde are combined to generate acetic anhydride.

[Safety and Protection]Acetic acid is a second-level organic acid corrosive substance, hazardous regulation number: 9400l. Packed in aluminum alloy or plastic barrels, the net weight of aluminum barrels is 100kg or 200kg, and the net weight of plastic barrels is 25L. Pay attention to fire and explosion protection during storage.

Acetic acid is non-toxic at low concentrations. When the concentration exceeds 5%, it is highly corrosive to the skin and has a strong irritating effect on the respiratory tract, esophagus, eyes, etc. when touched by the skin. It should be cleaned immediately with plenty of water or 2% baking soda solution.