Methyl methacrylate
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| Names | |
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Preferred IUPAC name
Methyl 2-methylprop-2-enoate
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| Other names
Methyl 2-methylpropenoate
methyl methacrylate MMA 2-(methoxycarbonyl)-1-propene |
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| Identifiers | |
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3D model (Jmol)
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| ChEBI | |
| ChemSpider | |
| ECHA InfoCard | 100.001.180 |
| KEGG | |
| RTECS number | OZ5075000 |
| UNII | |
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| Properties | |
| C5H8O2 | |
| Molar mass | 100.12 g·mol−1 |
| Appearance | Colorless liquid |
| Odor | acrid, fruity |
| Density | 0.94 g/cm3 |
| Melting point | −48 °C (−54 °F; 225 K) |
| Boiling point | 101 °C (214 °F; 374 K) |
| 1.5 g/100 ml | |
| Vapor pressure | 29 mmHg (20°C) |
| -57.3·10−6 cm3/mol | |
| Viscosity | 0.6 cP at 20 °C |
| Structure | |
| 1.6–1.97 D | |
| Hazards | |
| Main hazards | Flammable |
| Safety data sheet |
See: data page Methyl methacrylate MSDS |
| Flash point | 2 °C (36 °F; 275 K) |
| 435 °C (815 °F; 708 K) | |
| Explosive limits | 1.7%-8.2% |
| Lethal dose or concentration (LD, LC): | |
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LC50 (median concentration)
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18750 ppm (rat, 4 hr) 4447 ppm (mouse, 2 hr) 3750 ppm (rat) 4808 ppm (mammal) |
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LCLo (lowest published)
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4400 ppm (rat, 8 hr) 4400 ppm (rabbit, 8 hr) 4207 ppm (rabbit, 4.5 hr) 4567 ppm (guinea pig, 5 hr) |
| US health exposure limits (NIOSH): | |
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PEL (Permissible)
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TWA 100 ppm (410 mg/m3) |
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REL (Recommended)
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TWA 100 ppm (410 mg/m3) |
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IDLH (Immediate danger)
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1000 ppm |
| Supplementary data page | |
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Refractive index (n), Dielectric constant (εr), etc. |
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Thermodynamic
data |
Phase behaviour solid–liquid–gas |
| UV, IR, NMR, MS | |
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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 (what is   ?) |
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| Infobox references | |
Methyl methacrylate (MMA) 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. ACH is produced by condensation of acetone and hydrogen cyanide. The cyanohydrin is hydrolyzed in the presence of sulfuric acid to a sulfate ester of the methacrylamide, Methanolysis of this ester gives ammonium bisulfate and MMA. Although widely used, the ACH route coproduces substantial amounts of ammonium sulfate.
In fact the sulfate ester of the amide is initially produced as an adduct with sulfuric acid ((CH3)2C(OSO3H)C(O)NH2. H2SO4), which is removed in a cracking step. The sulfate ester is then methanolyzed (reacted with methanol):
As indicated in the last reaction, each kilogram of methyl methacrylate produced yields 2.5 kg of ammonium hydrogen sulphate, Disposal of this salt is energy intensive. This technology affords more than 3 billion kilograms per year.
The economics of the ACH route have been heavily optimized.
Given the scale of production, many methods have been developed starting from diverse two- to four-carbon precursors.
Ethylene is first hydroformylated to give propanal, which is then condensed with formaldehyde to produce methacrolein, The condensation is catalyzed by a secondary amine. Air oxidation of methacrolein to methacrylic acid completes the synthesis of the acid:
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