Removal of transition metal cations and their counteranions by crosslinked epoxy-amine polymer

Reaction of epichlorohydrin with ethylenediamine is very exothermic, and severe explosions occur, even when a few milliliters of the reagents are interacted without solvent. A controlled reaction has been achieved safely by suspension polycondensation of epichlorohydrin with ethylenediamine. 1,2-Diaminoethane units in the resulting crosslinked polymer provide high chelating ability for transition metal ions, such as Cu(II), Ni(II), Co(II), Cd(II), Fe(III), and Cr(III). Having all-amine ligating groups, the polymer represents unique properties and can sorb not only metal cations but also their counteranions, such as chloride, sulphate, nitrate, and acetate. The crosslinked polymer is stable hydrolytically and regenerable by acid without losing its activity. It can be recycled and offers a means of simultaneous removal of cations and anions fi om aqueous solutions. (C) 1998 John Wiley & Sons, Inc.