In polyethylene PE, stearic acid metal salt is widely used They are calcium stearate and zinc stearate, and in polypropylene PP, calcium stearate is the most widely used.
Polypropylene, referred to as PP, is a colorless, odorless, non-toxic, translucent solid material. Polypropylene (PP) is a thermoplastic synthetic resin with excellent properties. It is a colorless, translucent thermoplastic lightweight general-purpose plastic. It has chemical resistance, heat resistance, electrical insulation, high-strength mechanical properties and good high wear-resistance processing properties. This has made polypropylene rapidly used in machinery, automobiles, electronic appliances, construction, textiles, and packaging since its advent. It has been widely developed and applied in many fields such as agriculture, forestry, fishery and food industry.
The following suppliers of calcium stearate will take you to learn about calcium stearate and its role in polypropylene:
Calcium stearate It is a white powder, insoluble in water, cold ethanol and ether, soluble in hot benzene, benzene, turpentine and other organic solvents, slightly soluble in hot ethanol and ether. 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 lubricant, sliding agent, heat stabilizer, release agent, accelerator, etc. in plastics, machinery, rubber, paint and ink and other industries.
Calcium stearate is used as β-crystalline nucleating agent and halogen absorber for polypropylene.
Calcium stearate in polyacetal resin is used as a co-stabilizer and its acid capture ability can neutralize the formic acid produced during the oxidation of formaldehyde. The addition of stearic acid metal salt improves melt stability in composite extrusion. The relative decrease in volume melt index can be attributed to the reorganization of macromolecular radicals. The reorganization of macromolecular radicals leads to the formation of branched chains and gels. Therefore, formulas containing calcium stearate show better stability against “free radical recombination” than formulas containing zinc stearate. Calcium stearate is used in polypropylene to eliminate the negative effects of residual catalyst on resin color and stability.
PS: Calcium stearate is used as a heat stabilizer. The initial coloring effect of calcium stearate is very good, but its long-term effect is not very good. When zinc stearate is used as a heat stabilizer, the early coloring effect is not very good. Good, but the long-term effect is very good, so manufacturers generally use the two of them to produce calcium-zinc composite non-toxic stabilizers. Stearate can also be used as a lubricant in plastics to increase the processing flow of plastics.
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