Calcium stearate white powder, insoluble in water, soluble in hot benzene , benzene and turpentine and other organic solvents, slightly soluble in hot ethanol and ##. It decomposes slowly when heated to 400°C and is flammable. It decomposes into stearic acid and corresponding calcium salts when exposed to strong acid and is hygroscopic. Used as a non-toxic heat stabilizer for polyvinyl chloride and has excellent lubricity.
What is the thermal stabilization effect of calcium stearate?
Although the thermal stability effect is not as good as barium stearate, lead stearate, tin stearate and cadmium stearate. But it is cheap and easy to obtain, has low toxicity and good processing performance. It has a synergistic effect when used together with zinc soap and epoxy compounds to improve thermal stability.
Commonly used in food packaging films, medical equipment and other soft products that require non-toxicity. Used together with salt-based lead salt and lead soap in hard products, it can increase the gelation speed. Used in polyethylene and polypropylene to eliminate the negative effects of residual catalyst on resin color and stability.
It should be noted that the disadvantage of calcium stearate is that it has initial coloration. When heated above 100℃ for a long time, the white polyvinyl chloride plastic will turn reddish, especially in the formula The coloring is particularly serious when titanium dioxide is present. At this time, if you add 0.06~0.12%Na2CO3 or 0.09~0.19NaHCO3, this shortcoming can be overcome. However, because these substances are too alkaline, they are not often used in practice.
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