Zinc stearate is a white powder, insoluble in water, soluble in heat It contains organic solvents such as ethanol, benzene, toluene, and turpentine; it decomposes into stearic acid and corresponding salts when exposed to acids; it is a fire hazard under dry conditions, with an auto-ignition point of 900°C; it is hygroscopic. Zinc stearate is mainly used as a lubricant and release agent for styrene resin, phenolic resin, and amine resin. At the same time, it also has the functions of vulcanization activator and softener in rubber.
Identification method of zinc stearate:
1. Take about 25g of this product, heat 200ml of water and 60ml of dilute sulfuric acid, heat to make the fatty acids become Separate the oil layer and keep it aside; add dilute sulfuric acid to the water layer to acidify it, add 1 drop of 0.1% copper sulfate solution and a few drops of ammonium mercury thiocyanate test solution to form a purple precipitate.
2. Take the oil layer under identification (1) and wash it with boiling water until the washing liquid does not show sulfate reaction. Collect the oil layer in a small beaker, let it cool, discard the water layer, and heat the oil layer. Melt, filter while hot, and dry at 105°C for 20 minutes. Determine the freezing point according to law (General Rule 0613), it should not be lower than 54°C.
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