Description
A water soluble gum commonly used in binding media of paints. Gum arabic is the amorphous exudate from the stem of several species of Acacia trees, especially Acacia senegal and Acacia arabica, found in tropical and subtropical areas of the world. Most gum arabic coming from the sub-Sahara region in Africa. Gum arabic contains arabinose, galactose, rhamnose, and glucuronic acid. It is sold in the form of round lumps, granules, thin flakes or as a powder; all of which may be white or slightly yellowish. Gum arabic is completely soluble in hot and cold water, yielding a viscous solution. However, heating a gum arabic solution to the boiling point will cause it to darken and will change its adhesion properties. Aqueous solutions of gum arabic will precipitate or gel with the addition of ferric salts, borax, alcohol, or sodium silicate. Gum arabic is used in watercolor paints, inks, lithographs, and for textile sizing. The earliest known inks consisted of gum arabic and lampblack.
Synonyms and Related Terms
goma arábiga (Esp.); gomme d'acacia (Fr.); gomme arabique (Fr.); gomma di acacia (It); gomma arabica (It); kordofan; picked turkey; white sennar; senegal gum; ghezineh gum; gomme blonde; gomme blanche; gum acacia, East India gum; kami; wattle gum
| 9000-01-5 |
| 1.35-1.49 |
| 1.476 (solid) |
Other Properties
Soluble in hot and cold water, glycerol and propylene glycol. Insoluble in ethanol and hydrocarbon solvents. Very little autofluorescence. Produces no color in iodine.
Hazards and Safety
Skin contact and inhalation may cause allergic reactions. Nonflammable.
Mallinckrodt Baker: 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.
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Last updated on: 12/30/2009 7:03:42 AM
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