| 摘要 |
PURPOSE: A sulfonation process suitable for both macroporous bead polymers and for monodisperse-gel-form bead polymers is provided which gives the sulfonated products the increased osmotic and mechanical stability required to meet current standards and at the same time reliably provides high exchange capacity. CONSTITUTION: The sulfonation process for preparing macroporous or monodisperse-gel-type cation exchangers includes the step of (a) feeding a macroporous or monodisperse-gel-type bead polymer, without swelling agents, into sulfuric acid at temperatures of from 110 to 140 deg.C; (b) stirring the sulfuric-acid-treated bead polymer at a temperature of 110 to 140 deg.C. until complete sulfonation takes place; (c) subjecting the sulfonated bead polymer to cycles of stepwise dilution with sulfuric acids of decreasing concentration; and (d) washing the bead polymer with demineralized water.
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