Welan gum

Welan gum is an exopolysaccharide used as a rheology modifier in industrial applications such as cement manufacturing.[1] It is produced by fermentation of sugar by bacteria of the genus Alcaligenes. The molecule consists of repeating tetrasaccharide units with single branches of L-mannose or L-rhamnose.[2] In solution, the gum exhibits viscosity retention at elevated temperature, and is stable in a wide pH range, in the presence of calcium ion, and with high concentration of glycols.[3][4][5]

Welan gum
Identifiers
ECHA InfoCard 100.118.859
Properties
Appearance white to cream colored powder
Density 26.25 lbs/ft³ (bulk)
Hazards
Safety data sheet
NFPA 704 (fire diamond)
Flammability code 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilHealth code 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineReactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
1
1
0
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

See also

References
  1. US patent 5004506, "Welan gum in cement compositions", issued 2 April 1991, assigned to Merck & Co., Inc.
  2. Kaur, Varinder; Bera, Manav B.; Panesar, Parmjit S.; Kumar, Harish; Kennedy, J.F. (2014). "Welan gum: Microbial production, characterization, and applications". International Journal of Biological Macromolecules. 65: 454–461. doi:10.1016/j.ijbiomac.2014.01.061. ISSN 0141-8130.
  3. "CP Kelco Welan Gum". CP Kelco. Retrieved 17 Sep 2010.
  4. "Welan gum". Colltec. Retrieved 17 Sep 2010.
  5. "Welan gum". Fritz Industries. Retrieved 17 Sep 2010.


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