Methyl acrylate is an organic compound, more accurately the methyl ester of acrylic acid. It is a colourless liquid with a characteristic acrid odor. It is mainly produced to make acrylate fiber, which is used to weave synthetic carpets.[6] It is also a reagent in the synthesis of various pharmaceutical intermediates. Owing to the tendency of methyl acrylate to polymerize, samples typically contain an inhibitor such as hydroquinone.
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| Names | |||
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| Preferred IUPAC name
Methyl prop-2-enoate[1] | |||
| Other names | |||
| Identifiers | |||
3D model (JSmol)
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| ChEMBL | |||
| ChemSpider | |||
| ECHA InfoCard | 100.002.274 | ||
| KEGG | |||
PubChem CID
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| UNII | |||
CompTox Dashboard (EPA)
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| Properties | |||
| C4H6O2 | |||
| Molar mass | 86.090 g·mol−1 | ||
| Appearance | Colorless liquid | ||
| Odor | Acrid[2] | ||
| Density | 0.95 g/cm3[3] | ||
| Melting point | −74 °C (−101 °F; 199 K)[3] | ||
| Boiling point | 80 °C (176 °F; 353 K)[3] | ||
| 5 g/100 mL | |||
| Vapor pressure | 65 mmHg (20°C)[2] | ||
| Viscosity | |||
| Hazards | |||
| Occupational safety and health (OHS/OSH): | |||
Main hazards
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Harmful (Xn); Highly flammable (F+) | ||
| Flash point | −3 °C (27 °F; 270 K)[3] | ||
| Explosive limits | 2.8–25%[2] | ||
| Lethal dose or concentration (LD, LC): | |||
LC50 (median concentration)
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3575 ppm (mouse) 1350 ppm (rat, 4 hr) 1000 ppm (rat, 4 hr) 2522 ppm (rabbit, 1 hr)[5] | ||
| NIOSH (US health exposure limits): | |||
PEL (Permissible)
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TWA 10 ppm (35 mg/m3) [skin][2] | ||
REL (Recommended)
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TWA 10 ppm (35 mg/m3) [skin][2] | ||
IDLH (Immediate danger)
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250 ppm[2] | ||
| Safety data sheet (SDS) | Oxford MSDS | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Production
editThe standard industrial reaction for producing methyl acrylate is esterification of acrylic acid with methanol under acid catalysis (sulfuric acid, p-toluenesulfonic acid or acidic ion exchangers.[7]). The transesterification is facilitated because methanol and methyl acrylate form a low boiling azeotrope (boiling point 62–63 °C).[8]
The patent literature[9] describes a one-pot route involving vapor-phase oxidation of propene or 2-propenal with oxygen in the presence of methanol.
Other methods
editMethyl acrylate can be prepared by debromination of methyl 2,3-dibromopropanoate with zinc.[10] Methyl acrylate is formed in good yield on pyrolysis of methyl lactate in the presence of ethenone (ketene).[11] Methyl lactate is a renewable "green chemical". Another patent[12] describes the dehydration of methyl lactate over zeolites.
The nickel tetracarbonyl-catalyzed hydrocarboxylation of acetylene with carbon monoxide in the presence of methanol also yields methyl acrylate.[13] The reaction of methyl formate with acetylene in the presence of transition metal catalysts also leads to methyl acrylate.[14] Both, the alcoholysis of propiolactone with methanol as well as the methanolysis of acrylonitrile via intermediately formed acrylamide sulfate[15] are also proven but obsolete processes.
Use
editMethyl acrylate is after butyl acrylate and ethyl acrylate the third most important acrylic ester with a worldwide annual production of about 200,000 tons in 2007.[16] Poly(methyl acrylate) is a tacky material near room temperature, and as such it is not particularly useful as a structural material. Commonly, methyl acrylate (and other acrylate esters) are copolymerized with other alkenes to give useful engineering plastics.[17] A variety of vinyl monomers are used, including styrene and other acrylates.[18] The resulting copolymers give acrylic paints that are harder and more brittle than those with the homologous acrylates. Copolymerizing methyl acrylate with acrylonitrile improves their melt processability to fibers, which could be used as precursors for carbon fibers.[19] Methyl acrylate is the precursor to fibers that are woven to make carpets.
Amino derivatives
editMethyl acrylate reacts catalysed by Lewis bases in a Michael addition with amines in high yields to β-alanine derivatives which provide amphoteric surfactants when long-chain amines are used and the ester function is hydrolysed subsequently.
Acrylates are also used in the preparation of poly(amidoamine) (PAMAM) dendrimers typically by Michael addition with a primary amine.
Methyl acrylate is used for the preparation of 2-dimethylaminoethyl acrylate by transesterification with dimethylaminoethanol in significant quantities of over 50,000 tons / year.[20]
Reactions
editMethyl acrylate is a classic Michael acceptor, which means that it adds nucleophiles at its terminus. For example, in the presence of a base catalyst, it adds hydrogen sulfide to give the thioether:[21]
- 2 CH2CHCO2CH3 + H2S → S(CH2CH2CO2CH3)2
It is also a good dienophile.
Safety
editIt is an acute toxin with an LD50 (rats, oral) of 300 mg/kg and a TLV of 10 ppm.
References
edit- ^ a b "methyl acrylate - Compound Summary". PubChem. Retrieved June 30, 2012.
- ^ a b c d e f NIOSH Pocket Guide to Chemical Hazards. "#0394". National Institute for Occupational Safety and Health (NIOSH).
- ^ a b c d Record in the GESTIS Substance Database of the Institute for Occupational Safety and Health
- ^ a b George, John; Sastry, Nandhibatla V.; Patel, Sunil R.; Valand, Mahendra K. (2002). "Densities, Viscosities, Speeds of Sound, and Relative Permittivities for Methyl Acrylate + 1-Alcohols (C1−C6) atT= (308.15 and 318.15) K". Journal of Chemical & Engineering Data. 47 (2). American Chemical Society (ACS): 262–269. doi:10.1021/je010268l. ISSN 0021-9568.
- ^ "Methyl acrylate". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
- ^ Takashi Ohara; Takahisa Sato; Noboru Shimizu; Günter Prescher Helmut Schwind; Otto Weiberg; Klaus Marten; Helmut Greim (2003). "Acrylic Acid and Derivatives". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a01_161.pub2. ISBN 3-527-30673-0.
- ^ "Esterification: Acrylate esters (MA, EA, BA, MMA, 2-EHA)". amberlyst.com. Retrieved 2013-02-21.
- ^ Chessie E. Rehberg (1955). "n-Butyl acrylate". Organic Syntheses. 26: 18; Collected Volumes, vol. 3, p. 146.
- ^ US 3925463, Ferlazzo, Natale; Buzzi, Gian Fausto & Ghirga, Marcello, "Process for the production of methyl acrylate", published 1975-12-09, assigned to Societa' Italiana Resine S.I.R., S.p.A.
- ^ F. Beilstein: Handbuch der organischen Chemie, 3. Auflage, 1. Band. Verlag Leopold Voss, 1893, S. 501. Volltext.
- ^ US 2417748, Hagemeyer, Hugh J., "Preparation of methyl acrylate", published 1947-03-18, assigned to Eastman Kodak Company
- ^ US 5250729, Abe, Takafumi & Hieda, Shinichi, "Process for preparing unsaturated carboxylic acid or ester thereof", published 1993-10-05, assigned to Mitsubishi Gas Chemical Company
- ^ W. Reppe, J. Liebigs Ann. Chem., 582 (1), 116-132 (1953)
- ^ US 6022990, Liu, Zhao-Tie; Zhang, Jia-Qi & Yang, Xian-Gui, "Method for synthesizing methyl acrylate", published 2000-02-08, assigned to Chengdu Institute of Organic Chemistry and National Research and Engineering Centre for Coal Slurry Gasification and Coal Chemical Industry
- ^ H.-J. Arpe, Industrielle Organische Chemie, 6. Aufl., Wiley-VCH Verlag, Weinheim, 2007, ISBN 978-3-527-31540-6.
- ^ CEH Marketing Research Report Acrylic Acid and Esters, SRI Consulting, July 2007.
- ^ Penzel, Erich; Ballard, Nicholas; Asua, José M. (2018). "Polyacrylates". Ullmann's Encyclopedia of Industrial Chemistry. pp. 1–20. doi:10.1002/14356007.a21_157.pub2. ISBN 978-3-527-30673-2.
- ^ DOW Methyl acrylate, Product Safety Assessment
- ^ V. A. Bhanu; et al. (2002), "Synthesis and characterization of acrylonitrile methyl acrylate statistical copolymers as melt processable carbon fiber precursors" (PDF), Polymer (in German), vol. 43, no. 18, pp. 4841–4850, doi:10.1016/S0032-3861(02)00330-0
- ^ WO 2010136696, Paul, Jean-Michel; Tonnelier, Boris & Augustin, Francis, "Composition including dialkyl tin oxide and use thereof as a transesterification catalyst for the synthesis of (meth)acrylic esters", published 2010-12-02, assigned to Arkema
- ^ Edward A. Fehnel and Marvin Carmack (1950). "Methyl-β-dipropionate". Organic Syntheses. 30: 65; Collected Volumes, vol. 4, p. 669.