• 2022-05-23

(3)Suspension Crosslinking Copolymerization method Suspension polymerization is a method for preparing spherical polymers. Copolymerization is one of the ways to prepare binary or ternary copolymers and improve the properties of polymers. Suspension Crosslinking Copolymerization is a unique polymerization reaction used to prepare ion exchange resin skeleton copolymers. Suspension polymerization is...

• 2022-06-21

In addition to conventional ion exchange resins, micron fine-grained ion exchange resins are also developing rapidly. This kind of resin is mainly used for chromatographic separation. Therefore, a sufficiently small particle size (100~400 mesh) and a relatively narrow particle size distribution are key technical indicators. Suspension polymerization can prepare spheres with diameters ranging from ...

• 2022-10-12

The aforementioned suspension crosslinking copolymerization is an important method for preparing polymers. The copolymerization is carried out in a dispersed small ball. In fact, this is a micro bulk polymerization, and the product is a gel type transparent sphere. If a certain amount of inert solvent or linear polymer (collectively referred to as porogen) is added to the comonomer, the porogen wi...

• 2022-10-13

As a result, the preparation of macroporous ion exchange resin copolymer spheres can be divided into the following types: (1) Suspension copolymerization of macroporous ion exchange resin with non good solvent as porogen: the method is to mix monomer, initiator and porogen together for suspension copolymerization. From a single sphere, this is a micro precipitation copolymerization reaction. At th...

• 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 ...

• 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...

• 2022-10-17

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...

• 2022-10-19

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...

• 2022-10-20

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...

• 2022-10-24

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...

• 2022-10-25

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...

• 2022-10-26

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...