Properties of chelating resins prepared by addition of 1,4,8,11‐tetraazacyclotetradecane‐5,7‐dione to epoxy groups of poly(glycidyl methacrylate)s crosslinked with oligoethylene glycol dimethacrylates

Abstract

In order to improve Cu(II) adsorption ability of chelating resins based on a macrocyclic ligand 1,4,8,11-tetraazacyclotetradecane-5,7-dione (L) bound to crosslinked copolymers, the resins were prepared by reaction of L with poly(glycidyl methacrylate)s crosslinked with ethylene glycol dimethacrylate (1G), tetraethylene glycol dimethacrylate (4G) or nonaethylene glycol dimethacrylate (9G). By systematically changing the amounts of each crosslinker (degree of crosslinking) and of isobutyl acetate (IBA) as diluent in the suspension polymerization of the monomers, precursory copolymers with various degrees of crosslinking as well as with different specific surface areas (SSAs) were prepared, and then L was introduced into them. Ligand contents, SSAs, and Cu(II) adsorption abilities of the resulting resins were evaluated, and it was clarified that resins derived from precursors (prepared by using 4G or 9G in the presence of 120–160 vol % of IBA) exhibit high capacities for Cu(II), whereas the capacities of resins crosslinked with 1G are not so high. Further detailed study on the uptake of metal ions using the resins RG4D(10)-140 and RG9D(10)-140 (derived from the precursors prepared by using 10 mol % of the respective crosslinkers 4G and 9G in the presence of 140 vol % of IBA) showed that RG9D(10)-140 is much superior to RG4D(10)-140 in the column-mode adsorption of Cu(II). These results indicate that not only the selection of the suitable crosslinker but also the use of a pertinent amount of the diluent are very important in improving the complexing abilities of the polymer-bound L. © 1996 John Wiley & Sons, Inc.