【 Product name 】 Galla extract -- tannic acid

【 Name in English 】Tannic acid

【 English aliases 】 Chinese tannin;Gallotannic acid;Gallotannin;Galloylglucose;Glycerite;Penta NM digalloyl glucose;Quebracho;Tannins;1,3,6-tris-O-(3,4,5-trihydroxybenzoyl)hexopyranose;1,2,3,4,6-pentakis-O-[(3,4-dihydroxy-5-{[(3,4,5-trihydroxyphenyl)carbonyl]oxy}phenyl)carbonyl]hexopyranose

【CAS number】 1401-55-4

【EINECS number】 215-753-2

【Chemical formula】 C₇₆H₅₂O₄₆

【Molecular mass】 1701.20

【Trait 】 Pale yellow to light brown amorphous powder or loosely shiny scaly or spongy solid that can darken when exposed to air. Odourless, slightly specific odour with strong astringency, exposure to light and darker colour in air. Soluble in water, freely soluble in ethanol, acetone and glycerol, practically insoluble in diethyl ether, benzene, chloroform and petroleum ether. There was a special odor, with a strong astringency.

【 MP 】 210-215 ℃

【 Flash point 】 187 ℃

【 Storage 】 Protect from light is suitable

【 Use 】 Precipitation and gravimetric determination of beryllium, aluminum, gallium, indium, niobium, tantalum, and zirconium. Specific determination of copper, iron, vanadium, cerium and cobalt. Precipitants of proteins and alkaloids. External indicator when titrating lead with ammonium molybdate. Dye mordants. Industrially, tannic acid is heavily applied in tanning with the manufacture of blue ink. Tannins allow proteins to set. People chemically treat raw porcine skin, raw cattle cattle with tannic acid, which allows the soluble proteins in raw skin to solidify. Whereupon, it would have been put a few days of smelling and decaying raw crust into a nice, clean, pliable and enduring leather.

【 Physicochemical properties 】 Flammability substances. Autoignition point 526.6 ° C.