Chemistry:N,N'-Methylenebisacrylamide

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Short description: Chemical compound, polyacrylamide crosslinker


N,N′-Methylenebisacrylamide
Skeletal formula of methylenebisacrylamide
Ball-and-stick model of the methylenebisacrylamide model
Names
Preferred IUPAC name
N,N′-Methylenedi(prop-2-enamide)
Other names
bis
Identifiers
3D model (JSmol)
ChemSpider
EC Number
  • 203-750-9
MeSH C021221
UNII
Properties
C7H10N2O2
Molar mass 154.169 g·mol−1
Appearance white solid
Melting point 181–182 °C (358–360 °F; 454–455 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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N,N′-Methylenebisacrylamide (MBAm or MBAA, colloquially "bis") is the organic compound with the formula CH2[NHC(O)CH=CH2]2. A colorless solid, this compound is a crosslinking agent in polyacrylamides, e.g., as used for SDS-PAGE.[1][2]

Synthesis

Acrylamide reacts with an aqueous solution of formaldehyde in the presence of copper(I) chloride as a polymerization inhibitor and sulfuric acid as catalyst to form N,N′-methylenebisacrylamide with yields of 60 to 80%.[3][4]

MBA aus Acrylamid.svg

The reaction proceeds via N-hydroxymethylacrylamide, which can be detected in alkaline solution and decomposes in acid to give N,N′-methylenebisacrylamide. Using acrylamide and paraformaldehyde in 1,2-dichloroethane gives a clear solution upon heating, from which MBA crystallizes.

In aqueous media, acrylonitrile also reacts with formaldehyde to give crude N,N′-methylenebisacrylamide, which can be purified by recrystallization with acetone/water.[5]

Reactions and uses

Under basic conditions, MBA reacts further with formaldehyde at the amide nitrogen to give N-hydroxymethyl,N,N′-methylenebisacrylamide. Nucleophiles such as alcohols, amines, or thiols add across the activated vinyl groups, giving mixtures of mono- and disubstituted products.

Addition von Nukleophilen an MBA.svg

As a bifunctional electron-poor dienophile, MBA reacts with electron-rich dienes, such as cyclopentadiene, in Diels–Alder reactions, giving the corresponding norbornene adducts.

Diels-Alder mit MBA.svg

As a symmetric, unconjugated divinyl monomer, MBA can be used with suitable initiators in cyclopolymerizations to create linear, soluble polymers whose backbones are built from five- and seven-membered rings.[6][7] With acrylic and vinylic monomers such as acrylonitrile, acrylamide, and substituted acrylamides, MBA can undergo radical copolymerization to form highly crosslinked gels, using peroxides, UV light, or redox initiators.

Vernetztes Gel.svg

The properties of such gels are determined by the crosslink density, and targeted gel formation using MBA crosslinking gives useful technical properties used in various applications, such as in adhesives, paints, and superabsorbents. In biochemistry, MBA is used for chromatography gels and polyacrylamide gel electrophoresis.

See also

References

  1. Yuan-na Sun (2014). "Super Tough, Ultrastretchable, and Thermoresponsive Hydrogels with Functionalized Triblock Copolymer Micelles as Macro-Cross-Linkers". ACS Macro Letters 3 (5): 496–500. doi:10.1021/mz500221j. PMID 35590790. 
  2. Paez, Julieta I.; Farrukh, Aleeza; Ustahüseyin, Oya; Del Campo, Aránzazu (2018). "Biofunctionalization of Poly(acrylamide) Gels". Biomaterials for Tissue Engineering. Methods in Molecular Biology. 1758. pp. 101–114. doi:10.1007/978-1-4939-7741-3_8. ISBN 978-1-4939-7739-0. 
  3. "Alkylidene-bis-acrylamides" US patent 2475846A, issued 1946-10-31
  4. H., Petersen. Methods of Organic Chemistry, Vol. E20. pp. 1855. ISBN 978-3-13-219004-7. 
  5. Magat, Eugene E.; Faris, Burt F.; Reith, John E.; Salisbury, L. Frank (March 1951). "Acid-catalyzed Reactions of Nitriles. I. The Reaction of Nitriles with Formaldehyde 1" (in en). Journal of the American Chemical Society 73 (3): 1028–1031. doi:10.1021/ja01147a042. ISSN 0002-7863. https://pubs.acs.org/doi/abs/10.1021/ja01147a042. 
  6. Okada, Yukinori; Tanaka, Fumihiko (May 2005). "Cooperative Hydration, Chain Collapse, and Flat LCST Behavior in Aqueous Poly( N -isopropylacrylamide) Solutions" (in en). Macromolecules 38 (10): 4465–4471. doi:10.1021/ma0502497. ISSN 0024-9297. Bibcode2005MaMol..38.4465O. https://pubs.acs.org/doi/10.1021/ma0502497. 
  7. Behari, Kunj; Agrawal, Uma; Das, Rima (October 1993). "Gel Free Polymerization of N,N′-Methylenebisacrylamide Initiated by a Peroxodiphosphate-Thioacetamide Redox System. A Kinetic Study". Polymer Journal 25 (10): 1007–1013. doi:10.1295/polymj.25.1007. ISSN 0032-3896.