4,4′-Methylenedianiline (MDA) is an organic compound with the formula CH2(C6H4NH2)2. It is a colorless solid, although commercial samples can appear yellow or brown. It is produced on an industrial scale, mainly as a precursor to polyurethanes.
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| Names | |
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| Preferred IUPAC name
4,4′-Methylenedianiline | |
| Other names
4,4′-Diaminodiphenylmethane; 4,4′-Methylenebisbenzenamine; MDA; para,para′-Diaminodiphenylmethane; Dianilinomethane; 4,4′-Diphenylmethanediamine; Bis(4-aminophenyl)methane
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| Identifiers | |
3D model (JSmol)
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| ChEBI | |
| ChEMBL | |
| ChemSpider | |
| ECHA InfoCard | 100.002.705 |
| EC Number |
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| KEGG | |
PubChem CID
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| RTECS number |
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| UNII | |
| UN number | 2651 |
CompTox Dashboard (EPA)
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| Properties | |
| C13H14N2 | |
| Molar mass | 198.269 g·mol−1 |
| Appearance | Colorless solid |
| Odor | faint, amine-like[1] |
| Density | 1.05 g/cm3 (100°C) |
| Melting point | 89 °C (192 °F; 362 K) |
| Boiling point | 398 to 399 °C (748 to 750 °F; 671 to 672 K) |
| 0.125 g/100 ml (20 °C) | |
| Vapor pressure | 0.0000002 mmHg (20°C)[1] |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards
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potential carcinogen[1] |
| GHS labelling: | |
  
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| Danger | |
| H317, H341, H350, H370, H373, H411[2] | |
| P201, P260, P273, P280, P308+P313[2] | |
| Flash point | 190 °C; 374 °F; 463 K[1] |
| NIOSH (US health exposure limits): | |
PEL (Permissible)
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TWA 0.010 ppm ST 0.100 ppm[1] |
REL (Recommended)
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Ca[1] |
IDLH (Immediate danger)
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Ca [N.D.][1] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Synthesis and applications edit
In the industrial production, MDA is produced by reaction of formaldehyde and aniline in the presence of hydrochloric acid.[3]
MDA is a common monomer in the synthesis of polymer materials. These include polyamides,[4] polyimides and polyimines.[5] MDA is also used extensively as a precursor to Methylene diphenyl diisocyanate (MDI). Here, MDA is treated with phosgene to produce MDI. MDI, in turn, is a precursor to many polyurethane foams.[6][7] Lower quantities are used as hardeners in epoxy resins and adhesives, as well as in the production of high-performance polymers.[3] Additionally, hydrogenation of MDA can be performed to produce 4,4,diaminodicyclohexylmethane, which is also used in polymer chemistry.[8]
Safety edit
MDA is considered a potential occupational carcinogen by the US National Institute for Occupational Safety and Health. The Occupational Safety and Health Administration has set a permissible exposure limit at 0.01 ppm over an eight-hour time-weighted average, and a short-term exposure limit at 0.1 ppm.[9]
It is suspected carcinogen.[6] It is included in the "substances of very high concern" list of the European Chemicals Agency (ECHA).[7] The compound was blamed in a mass poisoning in the vicinity of Epping, Essex, United Kingdom during 1965 during which 84 individuals were poisoned through accidental contamination of flour used to make bread.[10]
Related compounds edit
References edit
- ^ a b c d e f g NIOSH Pocket Guide to Chemical Hazards. "#0415". National Institute for Occupational Safety and Health (NIOSH).
- ^ a b Record of 4,4'-Diaminodiphenylmethane in the GESTIS Substance Database of the Institute for Occupational Safety and Health, accessed on 12 February 2021.
- ^ a b "Data on manufacture, import, export, uses and release of 4-4' diaminodiphenylmethane" (PDF). Archived from the original (PDF) on 2011-10-01.
- ^ Endo T, Higashihara T (2022). "Direct Synthesis of Thermally Stable Semiaromatic Polyamides by Bulk Polymerization Using Aromatic Diamines and Aliphatic Dicarboxylic Acids". ACS Omega. 7 (10): 8753–8758. doi:10.1021/acsomega.1c06983. PMC 8928493. PMID 35309482.
- ^ Schoustra S, De Heer Kloots M, Posthuma J, Van Doorn D, Dijksman J, Smulders M (2022). "Raman Spectroscopy Reveals Phase Separation in Imine-Based Covalent Adaptable Networks". Macromolecules. 55 (23): 10341–10355. Bibcode:2022MaMol..5510341S. doi:10.1021/acs.macromol.2c01595. PMC 9753755. PMID 36530523.
- ^ a b "ToxFAQs for 4,4'-Methylenedianiline". Agency for Toxic Substances and Disease Registry.
- ^ a b "Background document for 4,4'-Diaminodiphenylmethane (MDA)" (PDF). European Chemicals Agency. Archived from the original (PDF) on 2017-08-22. Retrieved 2015-02-24.
- ^ Roose P, Eller K, Henkes E, Rossbacher R, Höke H (2005). "Amines, Aliphatic". Ullmann’s Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a02_001. ISBN 3-527-30673-0.
- ^ "4,4'-Methylenedianiline". NIOSH Pocket Guide on Chemical Hazards.
- ^ Kopelman H, Robertson MH, Sanders PG, Ash I (February 1966). "The Epping jaundice". British Medical Journal. 1 (5486): 514–6. doi:10.1136/bmj.1.5486.514. PMC 1843808. PMID 5902696.
External links edit
- "International Labour Organization". icsc1111.
- "NIOSH Pocket Guide to Chemical Hazards". Centers for Disease Control and Prevention.
- "European Union Risk Assessment Report" (PDF). Archived from the original (PDF) on 2007-03-17.
- Petersen JH, Mortensen SK, Pedersen GA (12 October 2004). "An acute case of primary aromatic amines migrating from cooking utensils" (PDF). Memorandum for the Danish Veterinary and Food Administration on. Danish Institute for Food and Veterinary Research.[dead link]