Barium stearate is in the form of white fine powder. The melting point is 160℃ and the relative density is 1.15. It is insoluble in water, insoluble in cold ethanol, soluble in hot ethanol, benzene, toluene and other non-polar solvents. It is water-absorbent in the air. It is heated and dissolved in organic solvents and turns into a gel after cooling. When encountering strong acid, it decomposes into stearic acid and the corresponding barium salt. Barium stearate is toxic, with a toxicity coefficient T=2. Typical symptoms of poisoning are vomiting, abdominal pain, diarrhea, increased blood pressure, and pulse disorder.
Preparation method:
1. Combine stearic acid and barium carbonate or barium hydroxide, or sodium stearate solution and dilute barium chloride Prepared by solution reaction.
2. It is prepared by reacting stearic acid with sodium hydroxide solution and then reacting with barium chloride solution.
3. Preparation of sodium stearate. Add stearic acid to the reaction kettle, dissolve it with 20 times (mass) hot water under stirring, and add caustic soda with a density of 1074kg/m3 at about 80°C. A dilute sodium stearate solution is produced.
4. Preparation of barium stearate. Add a barium chloride solution with a density of 1074kg/m3 to the sodium stearate solution prepared above, and conduct a metathesis reaction at about 70°C to produce barium stearate. Has precipitated out. After filtering, washing, and drying at 100 to 110°C, the finished product is obtained.
5. Suspend 48g of barium hydroxide [Ba(OH)2·8H2O] in 300mL of water at a temperature of 23°C. Then dissolve 95.3g stearic acid in 400mL water at 25°C, and add 4g ammonia water with a concentration of 28% to 29% to make an emulsion. Gradually add the stearic acid emulsion to the barium hydroxide suspension under full stirring within 1.5 hours. After obtaining a white insoluble product, filter it out and dry it to obtain the barium stearate product.
Usage:
This product can be used as a heat stabilizer for polyvinyl chloride and vinyl chloride copolymer, with excellent lubricity and long-term heat resistance. Good, the stabilizing effect is greater than calcium stearate, but not as good as lead stearate. It has good synergistic effect when used together with cadmium soap, zinc soap or epoxy compounds. The general dosage is 0.1~2%. Used together with a small amount of lead stabilizer, it can improve the electrical properties of the product.
Used as high temperature resistant lubricant for machinery and high temperature resistant powder for rubber products. It can be used as a stabilizer and lubricant for polyvinyl chloride. Among all stearates of alkaline earth metals, this product has the best long-term heat resistance.
Barium stearate is mainly used in transparent films, sheets, artificial leather, hard plates and pipes, etc. In soft products, it is often combined with cadmium, cadmium-zinc or cadmium-lead soaps.
Often used together with zinc soap in the formulation of vulcanization-resistant artificial leather. It is often combined with basic lead salt and lead soap in pipe and cable materials.
In corrugated plates, it is often combined with cadmium soap, lead soap and salt-based lead salts.
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