In the early 20th century, the study of emulsion polymerization technology was initiated. It means that the polymerization of non water soluble monomers in lotion form emulsion under the action of emulsifier and mechanical agitation. Before the carboxyl group is neutralized, the polymer is insoluble in water and has no thickening effect. After neutralization with alkaline substances such as sodium hydroxide or ammonia, the thickening performance is rapidly improved.
The main advantages of emulsion polymerization are: water in lotion is used as dispersant, organic solvent is not included, the cost is low, there is no problem of three wastes, and it is easy to mix with other waterborne components, and it is easy to mix lotion. The emulsion polymerization process is simple and controllable, and the lotion is stable. Because of the absence of oil-containing dispersing media, thickeners made by emulsion polymerization can be used for textile lotion, as well as for the rheological properties of oilfield water borne coatings, such as oil lotion, etc., and are more widely used than those prepared by inverse emulsion polymerization of oil dispersive media.
Lotion of emulsion lotion: anionic surfactant is produced in emulsion polymerization, and a large amount of foam is produced when mixing. The thickening effect of the unit dosage of the product is not good. Add a certain amount of sodium hydroxide or ammonia before use. The determination of the amount needs to be strictly calculated. Especially when using ammonia, it will produce a strong pungent taste and is not favored.
Although the synthesis of thickeners is mainly based on the inverse emulsion polymerization, the research on thickening agents by lotion polymerization has always been of great lotion at home and abroad. Okubo Masashi and others in Japan studied the synthesis of thickeners by emulsion polymerization. The effect of monomers on lotion of thickeners was discussed. It is concluded that acrylic acid is better than methacrylic acid for copolymerization. American patent US6197871 does not use emulsifiers, but uses lotion of acrylic acid, butyl acrylate and acrylamide to make emulsion thickening agent. Its thickening effect and dispersion stability are all good. Xu Shujiao and other selected ethyl acrylate as soft monomer, methacrylic acid and methyl methacrylate as hard monomers, a polyacrylate thickener was synthesized by emulsion polymerization. The thickening performance of the product is equivalent to that of a commercial thickener. The addition of reactive surfactant also makes the electrolyte resistance of thickeners better than that of commercial products, and can also be used for thickening of styrene acrylic lotion and other coatings, and the lotion effect is good. It has broad application prospects. Ye Gaoyong and other methods were used to synthesize lotion lotion acrylic thickening agent by emulsion polymerization. By adding reactive monomer and acrylate to the product, the thickening and electrolyte resistance of the product were improved. The water thickening agent had excellent electrolyte and thickening ability. Liu Shuling and other researchers have synthesized a polyacrylic acid anion salt thickener by introducing self-made reactive surfactant. The thickening ability of the product is close to that of the United lotion company’s thickener PTF, and its electrolyte resistance is better than that of PTF.
