It is acquired by polymerizing Carbomer as a monomer in the visibility of an initiator.
How Carbomer is Made
a. The cyanoethanol technique makes use of chloroethanol as basic material, and also sodium cyanide melon to obtain cyanoethanol. In the presence of sulfuric acid, cyanohydrin is hydrolyzed at 175 ° C to get acrylic acid.
Figure 1 reveals the synthesis of Carbomer by cyanoethanol method
b. Acrylonitrile hydrolysis approach Utilizing acrylonitrile as a resources, in the visibility of sulfuric acid, acrylonitrile is hydrolyzed to generate sulfate of acrylamide, and then hydrolyzed to get acrylic acid.
Figure 2 reveals the synthesis of Carbomer by acrylonitrile hydrolysis
c. Repe technique and also modified Repe method Liquify acetylene in tetrahydrofuran, include it to the response kettle after metering. In the existence of a stimulant composed of nickel bromide and also copper bromide, carbon monoxide gas and also water are passed through, as well as the response is carried out at 200-225 ° C. as well as 7.8-9.8 MPa.
Number 3 reveals the synthesis of Carbomer by the Repe method
d. Acrolein oxidation method Mix propylene, air, as well as water in a ratio of 1:10:6 (V), and after that pass into the first fluidized bed to catalyze light weight aluminum, vanadium, phosphorus, iron, aluminum, nickel, and also potassium. At 370 ~ 390 ℃ for 5.5 s, the line rate is 0.6 m/s. Then go into the second fluidized bed, remain for 2.25 s under the catalysis of aluminum-vanadium= tungsten, as well as control the response temperature at 270-300 ° C. The space-time yield of acrylic acid is 55-60 kg/m · h. This method is safe, light in air pollution and also low in expense, and is the main approach for residential as well as international production.
Figure 4 shows the synthesis of Carbomer by acrolein oxidation
Preparation of polyacrylic acid Add deionized water into the polymerization pot, warmth at 60-100 ° C, and start to drop the blended option of ammonium persulfate and also acrylic acid (configured with deionized water). After leaking, continue to keep mixing for 3 to 4 hrs. item. Include 530kg of deionized water to the polymerization kettle, add 41kg of peregal OS-15 and also mix to liquify. After that 4kg of sodium lauryl sulfate was added, and also after mixing and liquifying, 68kg of blended monomers (butyl acrylate, acrylonitrile) were added within 20min. After mixing for 15 mins, add 30 kg of 1.5% ammonium persulfate aqueous remedy, and coating adding within half an hour. After continuing to mix for 15 min, the temperature was slowly elevated to 70 ° C, as well as the mixed monomer (272 kg) was included dropwise, and the decline was finished in about 1 h. After the enhancement, the mix was mixed at 80 ° C for 1 h.
After the reaction is completed, the temperature is lowered to about 40°C, 70kg of peregal OS-15 is added, and after stirring for 15min, the product is filtered, and impurities are removed to obtain product e. The solution polymerization method is adopted, and acrylic acid is used as the raw material. to make. Acrylic acid polymerization is fast and exothermic. In order to control the polymerization process, in the preparation of Carbomer for circulating water treatment, acrylic acid is usually prepared into an aqueous solution of less than 40% for polymerization, and the polymerization temperature is usually controlled at 50 ~ 150 ℃. Commonly used initiators are ammonium persulfate and sodium sulfite. In the polymerization process, a small amount (<5%) of mercaptosuccinic acid and isopropanol are often added as retarders, and hydroquinone or catechol are used as polymerization inhibitors. agent. A certain stoichiometric amount of deionized water was added to the reactor equipped with an electric stirrer, a reflux condenser, a dropping funnel and a thermometer, and the stirring was started and the reaction temperature was raised to about 80°C. Alcohol is added to the reactor to be miscible with water. A stoichiometric amount of ammonium persulfate is prepared into a dilute solution with a metered amount of water, placed in the dropping funnel on the polymerization reactor, the metered amount of acrylic acid (AA) monomer is mixed with a certain amount of water, and placed in the polymerization reactor. in another dropping funnel. When the temperature of the water in the reactor reaches the temperature required for the reaction, the aqueous acrylic acid monomer solution and the aqueous initiator ammonium persulfate solution are added dropwise. After the reaction is completed, the polymer solution is cooled to room temperature, and samples are taken to analyze various technical indicators.