4,4'-Methylenedianiline
Chemical compound
From Wikipedia, the free encyclopedia
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.
| Names | |
|---|---|
| Preferred IUPAC name
4,4′-Methylenedianiline | |
| Other names
MDA dadpm | |
| 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 |
potential carcinogen[1] |
| GHS labelling: | |
| 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) |
TWA 0.010 ppm ST 0.100 ppm[1] |
REL (Recommended) |
Ca[1] |
IDLH (Immediate danger) |
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
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]
MDA can also be applied as a bidentate (bridging) ligand in the formation of metal-coordination complexes.[9]
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 0.1 ppm.[10]
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.[11]
