The matrix of ion exchange resin (ionresin), the main raw materials for manufacturing are styrene and acrylic acid (ester). They respectively react with the crosslinking agent divinylbenzene to form a long molecular backbone and crosslink A polymer with a chain network backbone structure. Styrene resin is used first, acrylic resin is used later.
Both types of resins have good adsorption performance, but they have different characteristics. Acrylic resin can exchange and adsorb most ionic pigments, has a large decolorization capacity, and the adsorbate is easy to wash out, which is convenient for regeneration. It can be used as the main decolorization resin in sugar factories. Styrene resins are good at adsorbing aromatic substances and polyphenolic pigments in sugar juice (including negatively charged or uncharged); however, it is difficult to elute during regeneration. Therefore, the sugar solution is coarsely decolorized with acrylic resin and then finely decolorized with styrene resin, which can give full play to the advantages of both.
“The degree of crosslinking of the resin, that is, the percentage of divinylbenzene used in the polymerization of the resin matrix, has a great influence on the properties of the resin. Generally, resins with a high degree of cross-linking polymerize relatively tightly, are firm and durable, have higher density, have fewer internal voids, and are more selective for ions; while resins with a low degree of cross-linking have larger pores and stronger decolorization ability , The reaction speed is faster, but the swelling property is greater during work, the mechanical strength is slightly lower, and it is relatively brittle and fragile. The cross-linking degree of ionic resins used in industrial applications is generally not less than 4%; the cross-linking degree of resins used for decolorization is generally not higher than 8%; the cross-linking degree of resins used solely to adsorb inorganic ions can be higher.
“In addition to the above two series of styrene and acrylic, ion exchange resins can also be made by polymerizing other organic monomers. Such as phenolic (FP), epoxy (EPA), vinyl pyridine (VP), urea-formaldehyde (UA), etc.