Methyl acrylate

• Propenoate
• Methyl acrylate

Colorless, pungent, volatile, highly flammable liquid

Liquid

0.95 g · cm -3

-74 ° C

80 ° C.

91 hPa ( 20 ° C)

Moderately in water ( 52 g · l-1 at 25 ° C)

1.3984

Risk

5 ml · m -3 or 18 mg · m-3

-362.2 KJ / mol

Template: Infobox chemical / molecular formula search available

Methyl acrylate, methyl often called, is a chemical compound selected from the group of acrylic acid esters and therefore the carboxylic acid ester. It is in the form of a colorless, pungent smelling liquid.

Production

Acrylic acid methyl ester can be prepared by debromination of 2,3- Dibrompropansäuremethylester with zinc and sulfuric acid.

In the pyrolysis of methyl lactate in the presence of ketene is formed in good yield methyl. Lactic acid methyl ester found in recent attention as a chemical compound made ​​of renewable raw materials ( " Green Chemical "). A recent patent describes the pyrolysis of methyl lactate in the zeolite, methyl acrylate results from the acid in 93% yield.

The found of Walter Reppe nickel carbonyl -catalyzed Hydrocarboxylation of acetylene with carbon monoxide in the presence of methanol also provides methyl acrylate. In the patent literature, a one-step synthesis route is described for methyl oxidation of propene or acrolein with oxygen in the vapor phase in the presence of methanol. The conversion of methyl formate to acetylene in the presence of transition metal catalysts also leads to methyl acrylate. The alcoholysis of propiolactone with methanol as well as a part of the methanolysis of the intermediate acrylonitrile on resulting acrylamide sulfate to the obsolete process for the preparation of acrylic acid methyl ester.

The availability of low-cost acrylic acid by the method of propene has made with methanol under acid catalysis (sulfuric acid, p- toluene sulfonic acid, acidic ion exchangers ) for industrial scale exclusively used standard reaction, the direct esterification.

Properties

Methyl acrylate is a colorless, pungent, volatile, highly flammable liquid (flash point -3 ° C). Their vapors are 2.97 times heavier than air and combine with air to form an explosive mixture. Methyl acrylate tends to spontaneous polymerization, especially under the influence of light or elevated temperature. The stabilizer is therefore 10 - added 20ppm hydroquinone monomethyl ether ( MEHQ). When stored in the presence of oxygen and below 35 ° C, the shelf life of at least one year.

Use

Methyl acrylate is butyl acrylate and ethyl acrylate according to the annual global production of about 200,000 tons per year, the third largest acrylic esters.

Such as ethyl acrylate and methyl ester reacts under the catalysis of Lewis bases in a Michael addition reaction with amines in high yields of β -alanine derivatives that provide amphoteric with use of long-chain amines and subsequent hydrolysis of the ester function surfactants.

Acrylic acid methyl ester is used in significant quantities over 50,000 tons / year for the production of 2- dimethylaminoethyl acrylate by transesterification with dimethylaminoethanol.

Its range of use as a comonomer during the polymerization with a variety of acrylic and vinyl monomers is substantially equal to that of the ethyl acrylate. With methyl acrylate as comonomer harder and more brittle acrylic paints are obtained as with the homologous acrylic acid esters. Copolymerization of acrylonitrile with methyl acrylate improves the processability in the melt to form fibers, as precursors for carbon fibers ( ' carbon fiber " ) may be of interest.

Acrylic acid methyl ester ( typically prepared by a Michael addition of a primary amine ) were used for the preparation of polyamidoamine dendrimers.

Safety

Methyl acrylate is toxic by oral ( LD50: 277 mg / kg rat), dermal ( LD50: 1,240 mg / kg rabbit) and in particular inhalational ( LD50: 4.75 mg/l/4h rat) recording. In the environment, the substance is readily biodegradable and non bio -accumulative. Because of the eyes, skin and schleimhaureizenden properties and the unpleasant pungent odor acrylic acid methyl esters must be handled in closed compartments.