Parametric studies on the synthesis of amidoximated adsorbent resins

The main goal of this study was to obtain acrylonitrile (AN)‐divinylbenzene (DVB) copolymer beads that can serve as the matrix for preparation of amidoxime resins. AN‐DVB amidoxime resin was synthesized via suspension polymerization and the effect of different parameters such as the speed of stirrer, the amounts of suspending agent, hydrophilic agent, diluent agent, and initiator on its properties was investigated by fractional factorial (Taguchi) experimental design method. This method gives much‐reduced variance for the experiments with optimum control parameters setting and provides a set of minimum experiments compared to the conventional methods. The results showed that the most effective parameters on the amidoximation of resins were hydrophilic agent content, speed of stirrer, and the amount of suspending agent, respectively. Furthermore, anion‐exchange capacity of the amidoxime resins was utilized as a criterion for the evaluation of amidoxime adsorbent groups and the adsorption potential of the synthesized resins was determined by cation‐exchange capacity. The amount of methylacrylate as a hydrophilic agent had the most significant effect on the ion‐exchange capacity of the final product. Swelling ratio was also measured to evaluate the adsorption capacity of the synthesized resin. The results showed that the amounts of hydrophilic and diluent agents had significant effects on swelling ratio of resin. Finally, cation‐exchange capacity and swelling ratio of amidoxime resin were changed greatly because of alkaline treatment, but it had no significant effect on the anion‐exchange capacity of the synthesized resin. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012