Anion exchange resin preparation method (1)

[Preparation]

Industrial currently most anion exchange resins are crosslinked polystyrene as a skeleton

Chloromethylation has the advantages of mild reaction conditions, high yield, easy to obtain anion exchange resins with high exchange capacity and stable performance, low cost and easy industrial production, but it also has some disadvantages

(1) Chloromethyl method using long-chain chloromethyl ethers

This method uses long-chain chloromethyl ethers instead of chloromethyl ether to avoid the use of chloromethyl ether

(2) Amido methylation method

The specific process of this method is to introduce amido methyl groups on cross-linked styrene through amido methylation reaction, and then hydrolyze to obtain a primary amine type weak base resin containing amino methyl groups, and then subject the weak base resin to tertiary amination or quaternary ammonium Reactions such as chemical reaction to obtain the corresponding weak base or strong base resin

The law was first proposed by Corte in 1961

Bayer AG announced a process for preparing anion exchange resin in patent 3882153: styrene-diethylene copolymer beads are first soaked in vinyl chloride, and diphthalimidoethylene and ferric chloride are added for condensation reaction.

Zhang Xiaotian and others also used N-methylolformamide to carry out the amide methylation reaction and prepared an anion exchange resin with a greater degree of cross-linking

The anion exchange resin prepared by the amide methylation method has the advantages of high exchange capacity, high mechanical strength, and good permeability, but the price of amide methylation reagent is high, the reaction conditions are relatively harsh, the requirements for equipment are high, and the energy consumption is high.