| 摘要 |
An aldehyde galactomannan gum is produced by oxidation of galactomannan gum with an aqueous solution of periodic acid or an alkali metal periodate in an amount of 0,01 to 1,0 mole, preferably 0,05 to 0,25 mole, per mole of anhydrohexose unit. Only the anhydrogalactose units may be oxidized. The gum may be guar or locust bean gum. The reaction may take place in the presence of acetic acid. A water-insoluble product may be produced in the presence of methanol, isopropanyl alcohol, tert-butyl alcohol, or acetone; or by mixing 1 part of gum containing less than 20% of water with 1-3 parts of aqueous periodic acid or periodate. The water-insoluble product may be made water-soluble by reaction with sodium bisulphate. A dry mixture of galactomannan gum and the oxidizing agent may be added to an aqueous medium having a pH of 4-7.
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