- Methyl methacrylate
Methyl methacrylate Identifiers CAS number ChemSpider UNII KEGG ChEBI ChEMBL RTECS number OZ5075000 Jmol-3D images Image 1 Properties Molecular formula C5H8O2 Molar mass 100.12 g mol−1 Appearance Colorless liquid Density 0.94 g/cm³ Melting point
-48 °C, 225 K, -54 °F
101 °C, 374 K, 214 °F
Solubility in water 1.5 g/100 ml Viscosity 0.6 cP at 20 °C Structure Dipole moment 1.6-1.97 D Hazards MSDS External MSDS Main hazards Flammable Flash point 2 °C (36 °F) Autoignition
435 °C (815 °F) Supplementary data page Structure and
n, εr, etc. Thermodynamic
Solid, liquid, gas
Spectral data UV, IR, NMR, MS (what is: /?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Methyl methacrylate is an organic compound with the formula CH2=C(CH3)COOCH3. This colourless liquid, the methyl ester of methacrylic acid (MAA) is a monomer produced on a large scale for the production of poly(methyl methacrylate) (PMMA).
The compound is manufactured by several methods, the principal one being the acetone cyanohydrin (ACH) route, using acetone and hydrogen cyanide as raw materials. The intermediate cyanohydrin is converted with sulfuric acid to a sulfate ester of the methacrylamide, methanolysis of which gives ammonium bisulfate and MMA. Although widely used, the ACH route coproduces substantial amounts of ammonium sulfate. Some producers start with an isobutylene or, equivalently, tert-butanol, which is sequentially oxidized first to methacrolein and then to methacrylic acid, which is then esterified with methanol. Propene can be carbonylated in the presence of acids to isobutyric acid, which undergoes subsequent dehydrogenation. The combined technologies afford more than 3 billion kilograms per year. MMA can also be prepared from methyl propionate and formaldehyde.
The principal application, consuming approximately 80% of the MMA, is the manufacture of polymethyl methacrylate acrylic plastics (PMMA). Methyl methacrylate is also used for the production of the co-polymer methyl methacrylate-butadiene-styrene (MBS), used as a modifier for PVC. Also used in fracture repair in small exotic animal species using internal fixation.
In 2010 the world experienced an MMA shortage, believed to be due to production facilities shutting down for economic reasons. One of the largest producers, Dow Chemical, surprised many purchasers when they announced a six month shut down of their plant that produced 60% of MMA.
- ^ William Bauer, Jr. "Methacrylic Acid and Derivatives" in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim. DOI: 10.1002/14356007.a16_441. Article Online Posting Date: June 15, 2000
- ^ http://www.chemsystems.com/reports/search/docs/abstracts/0405-2_abs.pdf
- ^ http://www.npr.org/templates/story/story.php?storyId=127095942
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