4,4'-Methylenedianiline
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IUPAC name
Bis(4-aminophenyl)methane
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Other names
4,4'-Diaminodiphenylmethane; 4,4'-Methylenebisbenzenamine; MDA; para, para'-Diaminodiphenyl-methane; Dianilinomethane; 4,4'-Diphenylmethanediamine
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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 | Pale brown, crystalline 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] |
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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4,4'-Methylenedianiline (MDA) is an organic compound with the formula CH2(C6H4NH2)2. It is a colorless or white solid. It is produced on industrial scale as a precursor to polyurethanes.
Synthesis and applications
In the industrial production, MDA is produced by reaction of formaldehyde and aniline in the presence of hydrochloric acid.[2] This reaction consumes the majority of aniline produced worldwide.[3]
MDA is consumed mainly as a precursor to 4,4 ́-methylene diphenyl diisocyanate (MDI). MDA is treated with phosgene to give MDI. MDI is a precursor to many polyurethane foams.[4][5] Lower quantities are used as hardeners in epoxy resins and adhesives, as well as in the production of high-performance polymers.[2] MDA is hydrogenated to give 4,4-diaminodicyclohexylmethane, which is also used in polymer chemistry.[6]
Safety
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 0.10 ppm.[7]
It is suspected carcinogen.[4] It is included in the "substances of very high concern" list of the European Chemicals Agency (ECHA).[5] 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.[8]
References
- ^ a b c d e f g NIOSH Pocket Guide to Chemical Hazards. "#0415". National Institute for Occupational Safety and Health (NIOSH).
- ^ a b Data on manufacture, import, export, uses and release of 4-4’ diaminodiphenylmethane as well as ... [1] Archived 2011-10-01 at the Wayback Machine
- ^ Christian Six; Frank Richter (2005). "Isocyanates, Organic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a14_611.
- ^ a b ToxFAQs for 4,4'-Methylenedianiline, Agency for Toxic Substances and Disease Registry
- ^ a b Background document for 4,4’-Diaminodiphenylmethane (MDA)
- ^ Karsten Eller; Erhard Henkes; Roland Rossbacher; Hartmut Höke (2005). "Amines, Aliphatic". Ullmann’s Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a02_001.
- ^ [2] NIOSH Pocket Guide on Chemical Hazards
- ^ Kopelman, H; Robertson, MH; Sanders, PG; Ash, I. "The Epping jaundice". Br Med J. 1: 514–6. doi:10.1136/bmj.1.5486.514. PMC 1843808. PMID 5902696.
External links
- International Labour Organization icsc1111
- Centers for Disease Control and Prevention NIOSH Pocket Guide to Chemical Hazards
- European Union Risk Assessment Report
- J.H. Petersen, S.K. Mortensen, G.A. Pedersen, Memorandum for the Danish Veterinary and Food Administration on An acute case of primary aromatic amines migrating from cooking utensils[permanent dead link], Danish Institute for Food and Veterinary Research, 12 October 2004