Gum tragacanth

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Description

An exudate from several species of shrubs of the genus Astragalus (especially Astragalus gummifer) found in the dry regions of Iran, Iraq, Syria, and Turkey. Gum tragacanth consists of a complex mixture of acidic polysaccharides containing galacturonic acid, galactose, fucose, xylose, and arabinose. Tragacanth gum is available in the form of dull white, translucent plates (fiori) or as a yellowish powder (biondo). A soluble fraction, tragacanthin, dissolves when added to water, whereas an insoluble fraction, bassorin (60-70% by wt.) swells to a gel-like state. A solution of gum tragacanth is prepared by wetting the powder with alcohol, then adding water and shaking. Aqueous solutions are slightly acidic with a pH of 5-6. Gum tragacanth is used for textile sizing and printing, pastel crayon production, leather curing, and furniture polishes.

Synonyms and Related Terms

goma de tragacanto (Esp.); gomma adragante (It); gomma tragacante (It); olibanum; tragacanth; gum dragon; gomme adragante; Smyrna tragacanth; Anatolian tragacanth; Persian tragacanth; gum elect; fiori; biondo

FTIR

MFA- Gum Tragancanth.jpg


Other Properties

Water swellable after wetting with ethanol. Soluble in alkali and hydrogen peroxide. Insoluble in ethanol.

CAS 9000-65-1
Density 1.25-1.384

Hazards and Safety

Combustible. Inhalation and skin contact may cause allergies.

Fisher Scientific: MSDS

Additional Information

R.Newman, M.Serpico, "Adhesives and Binders" in Ancient Egyptian Materials and Technology, P.Nicholson, I.Shaw (eds.), Cambridge University Press, 2000, p. 475-494.

Sources Checked for Data in Record

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