It is understood that stearic acid is a white flake, bead or block solid at room temperature. It is composed of saturated fatty acids mainly C16 and C18. It is insoluble in water, slightly soluble in benzene and carbon disulfide, easily soluble in hot ethanol, non-toxic and tasteless, and has the general chemical properties of organic carboxylic acids. Stearic acid is a fatty acid widely found in nature. Almost all oils contain stearic acid in varying amounts. The content is higher in animal fats. For example, the content in butter can reach 24%, and in vegetable oils it is less. , tea oil is 0.8%, palm oil is 6%, but the content of cocoa butter is as high as 34%. There are two main production methods for industrial stearic acid: fractionation method and pressing method. A decomposing agent is added to the hardened oil, and then it is hydrolyzed to obtain crude fatty acids, which are then washed, distilled, and decolorized to obtain the finished product, while glycerol is produced as a by-product.
Stearic acid is used as an additive in various types of PVC plastics and rubber:
It is used as a raw material for additives and raw materials for daily chemical products Stearic acid is widely used in the manufacture of PVC plastic pipes, plates, profiles, and films. It is a PVC heat stabilizer with good lubricity and good light and heat stabilization.
In plastic PVC pipes, stearic acid helps prevent “scorching” during processing. It is an effective heat stabilizer added in PVC film processing and can prevent exposure to vulcanization. Discoloration of finished films caused by chemicals in rubber industry Stearic acid plays an important role in the synthesis and processing of rubber.
Stearic acid is a widely used vulcanization activator in natural rubber, synthetic rubber and latex. It can also be used as a plasticizer and softener. In the process of producing synthetic rubber, stearic acid needs to be added as an emulsifier. When manufacturing foam rubber, stearic acid can be used as a foaming agent. Stearic acid can also be used as a release agent for rubber products.