More is the aqueous solution polymerization method. The quality requirements for acrylic acid monomers are relatively high, and the amount of initiator required is small, generally 0.01%~1.00% of the relative monomer mass; the reaction temperature should be lower at 20°C~60°C, and a suitable one should be selected. pH and monomer concentration. The acrylic acid is neutralized with NaOH solution to pH 10.5~11.0 after distillation to remove the polymerization inhibitor, and the initiator, anti-crosslinking agent fatty acid salt and retarder aniline compound are added; Polymerization at high temperature, the obtained colloid is dried in vacuum and crushed to obtain the product.
Acrylic acid is neutralized with sodium hydroxide solution, refined by cation exchange resin to prepare a quantitative concentration solution, and adjusted to pH = 10; under the condition of nitrogen flow, add 0.1% monomer mass of ammonium persulfate and 0.05% sodium bisulfite , Stir evenly and pour into the stainless steel tank. Stand still at 30°C to initiate polymerization, and use a 20°C water-cooled steel tank to remove the heat of polymerization in the lower part, so that the system temperature does not exceed 60°C, and keep warm for 2 hours to obtain a sodium acrylate glue with a relative molecular mass of more than 10 million.
Sodium Acrylate with medium and high relative molecular weight is easily soluble in water, and its COO-adsorption and the influence of steric effect on the structure make a small amount of positively charged ions in the solution precipitate out in the form of precipitation. Therefore, sodium polyacrylate with medium and high relative molecular weight can be used as a flocculant in the purification of electrolytic salt water, the separation of red mud in alumina production, and the treatment of industrial sewage. Sodium Acrylate with medium and high relative molecular weight has special effects on the flocculation of animal and plant proteins in biology, and can be used to recover a large amount of protein in food industry wastewater. Sodium polyacrylate with high relative molecular weight can produce a wide range of viscosity and fluidity, low addition amount can produce high viscosity, and the product viscosity is less affected by the ambient temperature. It can also permanently suspend insoluble components in the system, which helps to improve the stability of the product and prolong the storage period of the finished product. Therefore, it is often used as a thickener for cosmetics (such as facial masks, skin creams, etc.) in the daily chemical industry, and plays a very important role in the stability of cosmetic emulsions. Curative cosmetics tend to be more functional and diversified; use its film-forming properties to make hair styling agents, gel water, etc. It can also be used as a food preservative. Because medium and high sodium polyacrylates are non-toxic and soluble in water, they can be removed by washing before eating. Moreover, sodium polyacrylate can form a layer of polymer film on the surface of food, which can isolate food from air. The chelating effect of sodium polyacrylate on metal ions also helps to prevent food from spoiling. In the field of oilfield chemistry in the petroleum industry, it can be used as a viscosifier for drilling fluid, fluid loss reducer and clay stabilizer; in metallurgy, it can be used as a sand binder in the casting process to make the sand mold durable and of good quality; in textiles On the one hand, it can be used to modify synthetic fibers to make the printing and dyeing of chemical fibers firm, light-resistant and bright; it can be added to the ceramic body as a ceramic slurry water reducer, and it can enhance the dry strength of the body to a certain extent. In addition, it can also be used as a binder for wall materials, an anti-floating agent for pesticides, a thickener for acidifying liquids and pharmaceuticals, etc.
