The manufacturing process can generally be divided into two stages (take the synthesis of styrene-type ion exchange resins as an example): (1) Synthesis of cross-linked polymer masterbatch. Styrene and divinylbenzene are copolymerized by suspension to produce a cross-linked structure of granular styrene-divinylbenzene copolymer, resin particles with a diameter of 0.1 to 2.0 mm. The weight percentage of styrene-divinylbenzene in the monomer is customarily referred to as the "degree of cross-linking". Generally, it is 4 to 12%. (2) Introduction of functional groups with ion exchange capacity. Granular resin is sulfonated with concentrated sulfuric acid, and sulfonic acid group is introduced into the benzene ring of polymer chain, then it becomes strongly acidic cation exchange resin; when quaternary ammonium salt group is introduced into the benzene ring, then it becomes strongly alkaline anion exchange resin; when chelating group is introduced, such as -N(CH2COOH)2, then it produces chelating ion exchange resin.
