Hexamethylenediamine

Last updated
Hexamethylenediamine [1] [2]
1,6-diaminohexane-2D-skeletal.svg
1,6-diaminohexane-3D-balls.png
1,6-diaminohexane-3D-vdW.png
Names
Preferred IUPAC name
Hexane-1,6-diamine [3]
Other names
  • 1,6-Diaminohexane
  • 1,6-Hexanediamine
Identifiers
3D model (JSmol)
1098307
ChEBI
ChEMBL
ChemSpider
DrugBank
ECHA InfoCard 100.004.255 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 204-679-6
2578
MeSH 1,6-diaminohexane
PubChem CID
RTECS number
  • MO1180000
UNII
UN number 2280
  • InChI=1S/C6H16N2/c7-5-3-1-2-4-6-8/h1-8H2 X mark.svgN
    Key: NAQMVNRVTILPCV-UHFFFAOYSA-N X mark.svgN
  • NCCCCCCN
Properties
C6H16N2
Molar mass 116.208 g·mol−1
AppearanceColourless crystals
Density 0.84 g/mL
Melting point 39 to 42 °C (102 to 108 °F; 312 to 315 K)
Boiling point 204.6 °C; 400.2 °F; 477.7 K
490 g L−1
log P 0.386
Thermochemistry
−205 kJ mol−1
Hazards
GHS labelling:
GHS-pictogram-acid.svg GHS-pictogram-exclam.svg
Danger
H302, H312, H314, H335
P261, P280, P305+P351+P338, P310
NFPA 704 (fire diamond)
3
2
0
Flash point 80 °C (176 °F; 353 K)
Explosive limits 0.7–6.3%
Lethal dose or concentration (LD, LC):
  • 750 mg kg−1(oral, rat)
  • 1.11 g kg−1(dermal, rabbit)
Related compounds
Related alkanamines
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Hexamethylenediamine is the organic compound with the formula H2N(CH2)6NH2. The molecule is a diamine, consisting of a hexamethylene hydrocarbon chain terminated with amine functional groups. The colorless solid (yellowish for some commercial samples) has a strong amine odor. About 1 billion kilograms are produced annually. [4]

Contents

Synthesis

Hexamethylenediamine was first reported by Theodor Curtius. [5] It is produced by the hydrogenation of adiponitrile:

NC(CH2)4CN + 4 H2 → H2N(CH2)6NH2

The hydrogenation is conducted on molten adiponitrile diluted with ammonia, [6] typical catalysts being based on cobalt and iron. The yield is good, but commercially significant side products are generated by virtue of reactivity of partially hydrogenated intermediates. These other products include 1,2-diaminocyclohexane, hexamethyleneimine, and the triamine bis(hexamethylenetriamine).

An alternative process uses Raney nickel as the catalyst and adiponitrile that is diluted with hexamethylenediamine itself (as the solvent). This process operates without ammonia and at lower pressure and temperature. [4]

Applications

Hexamethylenediamine is used almost exclusively for the production of polymers, an application that takes advantage of its structure. [7] [8] It is difunctional in terms of the amine groups and tetra functional with respect to the amine hydrogens. The great majority of the diamine is consumed by the production of nylon 66 via condensation with adipic acid. Otherwise hexamethylene diisocyanate (HDI) is generated from this diamine by phosgenation as a monomer feedstock in the production of polyurethane. [9] [10] The diamine also serves as a cross-linking agent in epoxy resins. [11] [12] [13]

Safety

Hexamethylenediamine is moderately toxic, with LD50 of 792–1127 mg/kg. [4] [14] [15] Nonetheless, like other basic amines, it can cause serious burns and severe irritation. Such injuries were observed in the accident at the BASF site in Seal Sands, near Billingham (UK) on 4 January 2007 in which 37 persons were injured, one of them seriously. [16] [17]

See also

Related Research Articles

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<span class="mw-page-title-main">Epoxy</span> Type of material

Epoxy is the family of basic components or cured end products of epoxy resins. Epoxy resins, also known as polyepoxides, are a class of reactive prepolymers and polymers which contain epoxide groups. The epoxide functional group is also collectively called epoxy. The IUPAC name for an epoxide group is an oxirane.

<span class="mw-page-title-main">Thermosetting polymer</span> Polymer obtained by irreversibly hardening (curing) a resin

In materials science, a thermosetting polymer, often called a thermoset, is a polymer that is obtained by irreversibly hardening ("curing") a soft solid or viscous liquid prepolymer (resin). Curing is induced by heat or suitable radiation and may be promoted by high pressure, or mixing with a catalyst. Heat is not necessarily applied externally, but is often generated by the reaction of the resin with a curing agent. Curing results in chemical reactions that create extensive cross-linking between polymer chains to produce an infusible and insoluble polymer network.

<span class="mw-page-title-main">Hot-melt adhesive</span> Glue applied by heating

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<span class="mw-page-title-main">Hexamethylene diisocyanate</span> Chemical compound

Hexamethylene diisocyanate (HDI) is the organic compound with the formula (CH2)6(NCO)2. It is classified as an diisocyanate. It is a colorless liquid. It has sometimes been called HMDI but this not usually done to avoid confusion with Hydrogenated MDI.

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A thermoset polymer matrix is a synthetic polymer reinforcement where polymers act as binder or matrix to secure in place incorporated particulates, fibres or other reinforcements. They were first developed for structural applications, such as glass-reinforced plastic radar domes on aircraft and graphite-epoxy payload bay doors on the Space Shuttle.

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<span class="mw-page-title-main">Isophorone diamine</span> Chemical compound

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<span class="mw-page-title-main">Tetramethylxylylene diisocyanate</span> Chemical compound

Tetramethylxylylene diisocyanate (TMXDI) is an organic compound is an organic compound with the formula C6H4(CMe2NCO)2 (Me = CH3). The molecule features two isocyanate groups. It was introduced in the 1980s by American Cyanamid. TMXDI is generally classified as an aliphatic isocyanate. Aliphatic isocyanates generally exhibit enhanced UV stability compared to their aromatic counterparts.

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<span class="mw-page-title-main">1,2-Diaminocyclohexane</span> Chemical compound

1,2-Diaminocyclohexane (DACH) is an organic compound with the formula (CH2)4(CHNH2)2. It is a mixture of three stereoisomers: cis-1,2-diaminocyclohexane and both enantiomers of trans-1,2-diaminocyclohexane. The mixture is a colorless, corrosive liquid, although older samples can appear yellow. It is often called DCH-99 and also DACH.

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2-Methylpentamethylenediamine is an organic compound part of the amine family with the formula H2NCH2CH2CH2CH(CH3)CCH2NCH2. A colorless liquid, this diamine is obtained by the hydrogenation of 2-methylglutaronitrile.

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References

  1. Merck Index, 11th Edition, 4614.
  2. MSDS
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  5. Curtius, Theodor and Clemm, Hans (1900) "Synthese des 1,3-Diaminopropans und 1,6-Diaminohexans aus Glutarsäure resp. Korksäure" (Synthesis of 1,3-diaminopropane and 1,6-diaminohexane from glutaric acid and suberic acid, respectively), Journal für praktische Chemie, 2nd series, 62 : 189–211.
  6. "SRIC Report - Report 31C - Advances in Adiponitrile (ADN) and Hexamethylenediamine (HMDA) Processes | IHS Markit". ihsmarkit.com. Retrieved 2019-02-19.
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  10. Hu, Jin; Chen, Zhuo; He, Yong; Huang, Hong; Zhang, Xinya (2017-05-01). "Synthesis and structure investigation of hexamethylene diisocyanate (HDI)-based polyisocyanates". Research on Chemical Intermediates. 43 (5): 2799–2816. doi:10.1007/s11164-016-2795-1. ISSN   1568-5675. S2CID   100565578.
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  16. BBC News
  17. BBC News