Understand glacial acetic acid in one article! Properties and main uses of glacial acetic acid

[alias] Glacial acetic acid, anhydrous acetic acid, ice acetic acid.

[Molecular formula]C2H4O2

[Structural formula]CH3COOH

[Properties]98%-100% acetic acid forms ice at 16°C. Hence the name, when the temperature is above 16°C, it is a colorless transparent liquid with a pungent special smell. It tastes sour when fully diluted with water. Hygroscopic leaf-like crystals below 16°C. The boiling point is 118°C, the relative density at 0°C is 1.086, and the viscosity is 11 .83mPa·s (20°C). When mixed with a small amount of water, it will generate heat, reduce capacity, and increase relative density. The relative density is the highest when the concentration is 77% -79%. Ice When acetic acid crystallizes at 16°C, the volume expands, and the glass bottle will often be blown. In hot weather in summer, the overflow of glacial acetic acid vapor will increase the pressure inside the bottle and cause the cork to jump off, so it should be stored at 17-32 Indoor at ℃. It can be dissolved with water, ethanol, propylene glycol, glycerin and carbon tetrachloride. It will produce white smoke when it contacts with ammonia. It has strong dissolving ability, can dissolve phosphorus and sulfur, and can also dissolve fat, oil, resin, pigment, Protein, etc. React with most metal oxides and organic bases to form acetate. Its vapor can pass through polyethylene film. It is very stable to oxidants and will not be oxidized by strong oxidants (such as potassium permanganate, etc.) at room temperature. Skin contact It has a stimulating and burning sensation. When the temperature is close to the boiling point, it burns with a weak blue flame and generates carbon dioxide and water vapor.

[Use] Glacial acetic acid is an important organic chemical raw material. It is used in the synthesis of vinyl acetate, acetate, acetate, thioglycolic acid and chloroacetic acid, etc. It is also used as a solvent for the manufacture of rubber, plastics, dyes, etc. In the printing and dyeing industry, it is used as an anti-alkali agent for dye developing solution, a preparation agent for pigment printing adhesive, as well as a dyeing aid and a dyeing retarder. The food industry is used as a sour agent and spice. In the fermentation industry, it is used as a flavor enhancer for koji wine. It is also a raw material for the manufacture of dyes, medicines, pesticides, and synthetic fibers. It is also used as a disinfectant, fungicide, etc.

[Brief recipe]

① Glacial acetic acid can be produced by liquid-phase oxidation of acetaldehyde and air or oxygen under the action of manganese acetate and cobalt acetate catalysts.

② Synthesize glacial acetic acid from methanol and carbon monoxide under the action of a catalyst.

③ Butane or naphtha and homogeneous catalysts (manganese acetate, cobalt acetate) are dissolved in glacial acetic acid, and the oxidation reaction is carried out by feeding air under high pressure. It can be made into glacial acetic acid.

［Safety and Protection］ Glacial acetic acid is a Class II organic acid corrosive substance, hazard code number: 9400l. Packed in aluminum alloy or plastic barrels, the net weight of each barrel is 100kg, 200kg in aluminum barrels, and 25L in plastic barrels. Pay attention to fire and explosion protection during storage.

Low-concentration glacial acetic acid is non-toxic, and 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. Skin contact Should immediately wash with plenty of water or 2% baking soda solution.