Sulfonation of styrene divinylbenzene

Low-capacity cation-exchange resins are obtained by superficial sulfonation of styrene-divinylbenzene copolymer beads. The resin beads are treated with concentrated sulfuric acid and a thin layer of sulfonic acid groups is formed on the surface. The final capacity of the resin is related to the thickness of the layer and is dependent on the type of resin, the bead diameter, and the temperature and time of contact with the sulfuric acid. Typical capacities range from 0.005 to 0.1 mequiv g . ... 

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