Synthesis and Characterization of a Few Amino-Functionalized Copolymeric Resins and Their Environmental Applications

The synthetic copolymeric resins acrylonitrile/divinylbenzene/vinylbenzyl chloride (AN/DVB/VBC), styrene/divinylbenzene/vinylbenzyl chloride (ST/DVB/VBC), and vinylbenzyl chloride/divinylbenzene (VBC/DVB) have been prepared by suspension polymerization. These polymeric matrixes were aminated with ethylenediamine (ED) and then protonated to increase their selectivity toward Cr(VI). The experiments were carried out in batch mode to optimize various influencing parameters, namely, contact time, pH, other interfering co-ions, and temperature. The chromium removal capacity (CRC) of AN/DVB/VBC ED resin was found to be higher than those of the other prepared copolymers. The mechanism of chromium removal was governed by electrostatic-adsorption-coupled reduction and complexation. The polymeric resins and chromium-sorbed resins were characterized by FTIR, SEM-EDAX, BET, elemental analysis, and EPR studies. The adsorption data were fitted with Freundlich and Langmuir isotherms. The calculated values of thermodynamic parameters indicated the nature of chromium sorption.