Acrylic acid is one of the simplestrepresentatives of carboxylic unsaturated monobasic acids. Its formula is as follows: CH2 = CH-COOH. It is a colorless liquid with a sharp and unpleasant odor. Soluble in water, chloroform, diethyl alcohol and ethanol, easily polymerizes with the further formation of polyacrylic acid. Acrylic acid has other names: ethenic acid and propenic acid.
How do (or synthesize) acrylic acid?
1.Currently, acrylic acid is produced by vapor-phase oxidation of propylene with oxygen (O 2) on molybdenum, cobalt or bismuth catalysts. An example is the following reaction:
CH2 = CH-CH3 (propylene) + O2 (oxygen) = CH2 = CH-COOH (acrylic acid)
2. In the past, a reaction was used in which carbon monoxide II (CO), acetylene (CH≡CH) and water (H2O) reacted. The chemical reaction will be as follows:
CHNCH (acetylene) + CO (carbon monoxide II) + H2O (water) → CH2 = CH-COOH (acrylic acid).
Another formaldehyde reaction with ketene was used:
CH2 = C = O (ketene) + H2C = O (formaldehyde) → CH2 = CH-COOH (propenic acid).
3. Now Rohm and Haas is creating a special technology for the synthesis of ethanecarboxylic acid from propane.
Chemical properties of acrylic acid
The acid we are considering can formsalts, esters, anhydrides, amides, acid chlorides and other compounds. It can also enter the addition reactions that are characteristic of ethylene carbons. The addition of water, proton acids and NH3 occurs not according to Markovnikov's rule. In this case, substituted derivatives are formed. Acrylic acid is involved in the synthesis of dienes. It also condenses with various salts of aryldiazonium. With ultraviolet irradiation, it forms polyacrylic acid.
Application of acrylic kilo
- is used as raw material in the production of a wide range of polymer products with various chemical and physical properties (for example, plastics and coatings);
- is used in the manufacture of dispersions foracrylic water paint and varnish materials; while the scope of such paints will depend on the chemical properties of the copolymer - from the final coloration of vehicles and to the painting of ceilings;
- Acrylic acid and its derivatives are usedfor the creation of impregnation for leather and fabrics, emulsions for paintwork materials, as a raw material for acrylate rubbers and polyacrylonitrile fibers, building adhesives and mixtures; esters of methacrylic and acrylic acids (in most cases methyl methacrylate and methyl acrylate esters are used) are used in the production of polymers;
- often acrylic acid is used in the creation of superabsorbents.
Proper storage of acrylic acid
When storing this substance for the purpose of avoidanceThe inhibitor hydroquinone is added to the polymerization. Before use, the acid must be distilled with caution, since it is possible to develop explosive polymerization.
Safety in use
When working with acrylic acid,that the substance has an irritant effect on the skin and mucous membranes. The threshold of the irritating action of the acid is 0.04 mg / liter. If you get on the mucous membrane of eyeballs, as a rule, causes severe burns of the cornea, can lead to irreversible changes (damage that can not be cured). The inhalation of vapors of acrylic acid can cause headache, irritation of the respiratory tract, and in excessive doses - the development of pulmonary edema. In rooms where work is being done with acrylic acid, constant air control is necessary. The maximum permissible concentration for this acid is 5 mg / m 3. Safety measures must be followed when working with other derivatives. As an example, you can bring nitrile acrylic acid.
