• 2022-10-31

3. Synthesis of weakly basic anion exchange resin Chloromethylstyrene divinylbenzene copolymer can be aminated with many amines, and the aminated product with primary amine and secondary amine is weak base anion exchange resin. The hydration ability of weak base group is slightly poor, and the expansion in alkaline solution is also small, so the amination reaction can be faster. Especially, the ma...

• 2022-10-26

2. Synthesis of strong basic anion exchange resin Among anion exchange resins, the yield of quaternary ammonium based strong alkaline resin is the largest. The main variety is gel type resin containing one N+(CH3) 3, with a crosslinking degree of 7 or 8, called strong base type I. Another ion exchange resin containing one N+(CH3) 2CH2CH2OH group is called strong base II. Strong basic anion exchang...

• 2022-10-25

Under the action of catalyst, chloromethylation of chloromethyl ether and polystyrene is easy to proceed. The reaction rate depends on the nature, amount and temperature of catalyst. When ZnCl2 is used as catalyst, the reaction rate constant is proportional to the amount of ZnCl2 used. For AICl3 and SnCl4, the logarithm of the reaction rate constant is proportional to its dosage. It can be seen th...

• 2022-10-24

Anion exchange resins produced in industry are mostly made of styrene divinylbenzene copolymer spheres as the skeleton, and introduced quaternary ammonium groups or other amine groups through chloromethylation and amination. Its varieties and specifications are far more than those of cation exchange resin. Therefore, it is widely used and one of the main strains of ion exchange resin. The basic sy...

• 2022-10-20

4. Swelling agent In industry, dichloroethane is used as swelling agent to prepare strong acid cation exchange resin, but this is not the best choice. Dichloroethane cannot be miscible with sulfuric acid, and the diffusion of sulfuric acid into the resin becomes the control factor of sulfonation rate. Dimethyl sulfoxide can be miscible with sulfuric acid, which is conducive to the diffusion of sul...

• 2022-10-19

2. Composition of crosslinking agent The common crosslinking agent of cation exchange resin is divinylbenzene. The isomer of the crosslinking agent divinylbenzene has a great influence on the structure of the copolymer, so it can significantly affect the rate of sulfonation reaction. The effect of the amount of divinylbenzene on the sulfonation rate of the copolymer is very clear, but the effect o...

• 2022-10-17

Strong acid cation exchange resin is made by sulfonation reaction, introducing sulfonic group into the benzene ring of cross-linked polystyrene. The sulfonation of aromatic rings is a typical electrophilic substitution reaction. In addition to concentrated sulfuric acid and chlorosulfonic acid, sulfur trioxide and oleum can also be used as sulfonating agents. Therefore, in addition to our most com...

• 2022-10-15

(3) Suspension copolymerization with mixed solvent as pore forming agent: macroporous ion exchange resins prepared by suspension copolymerization with good solvent or bad solvent as pore forming agent differ greatly in pore structure and performance, which indicates that the properties of pore forming agent have a very significant impact on the pore structure of copolymer. This effect is mainly at...

• 2022-10-14

When the macroporous ion exchange resins is used as a porogen in a bad solvent, the properties, dosage and crosslinking degree of the porogen have significant effects on the pore structure of the copolymer. With the increase of the amount of divinylbenzene and pore forming agent, the phase separation appeared earlier and the gel point also appeared earlier. The separated macromolecular chains are ...