Tannic acid is mainly used as a mordant in dyeing. It is also used to prepare citric acid and pyroic acid. It can also be used to make leather tanning agents, rubber coagulants, protein and alkaloid precipitants, and to measure antimony, aluminum and nickel. A reagent for metals such as copper.
The tannic acid powder is pale yellow to light brown amorphous powder obtained by evaporation and drying of the extract of Galla chinensis is industrial tannic acid, containing more than 80% tannic acid, and also contains a small amount of gallic acid, m-gallic acid, and three galls. Acid and pentayl gluconate and the like. Tannic acid is based on 1,3,4,6-tetra-O-galloyl-2-poly-O-galloyl-β-D glucose, and one molecule of glucose is combined with 8-9 gallic acid. The ester formed. Tannic acid is easily hydrolyzed by acid or enzyme, and the hydrolyzed product is gallic acid and glucose.
The main effects of industrial tannic acid:
1. It is used as raw material for gallic acid and pyrogal acid.
2. Mordant. Used for fiber fixing or dyeing, as a base-based dye.
3. Ore flotation agent. Rare metal smelting, extracting from lead-zinc ore, extracting rare metals such as bismuth and antimony from solution, and extracting lead and copper from chalcopyrite.
4 . Conversion coatings. Aluminum and its alloy plates, steel, copper, zinc surface corrosion protection.
5. Food additives. Such as food antioxidants, beverage clarifiers, advanced inks and inks.
6. Drilling mud thinner.
7. Synergist. Synthesis of 2,4-diamino-5-(3,4,5-trimethoprimam), referred to as TMP or sulfonamide synergist.
8. Deodorant. It is used for smells such as ammonia in refrigerators, warehouses and toilets.
Medical use of tannic acid:
In addition, tannic acid can also be used to synthesize cardiac diseases such as keguandiamine and keguanzhuo; synthetic biphenyl diester for the treatment of hepatitis B; and synthetic bismuth-273 for the treatment of schistosomiasis.
Tannic acid can inhibit bacterial growth and intestinal toxin absorption, and can be used for preventing and treating diarrhea. Medicinal tannins can be directly used in beverages, frozen products, confectionery, ice cream, meat products; as a burn, burn wound astringent, gastrointestinal hemostatic agent to prevent infection; can be made into glycerin, citrate, tannic acid Ointments, anti-cold agents (N-biguanidinomorpholine tannins), health promoters, insect repellents, insecticides, anti-radiation agents, contraceptives and special toothpastes.