Metal ion uptake by ion-exchange/chelating resins modified with cyclohexene oxide and cyclohexene sulphide

A ring opening reaction with either cyclohexene oxide or cyclohexene sulphide has been used in the modification of two types of polymeric resins. Both resins contained amino groups, one being obtained by reacting the vinylbenzyl chloride/divinylbenzene (VBC/DVB) copolymer with ethylenediamine, the second by reacting the VBC/DVB copolymer with diethyl malonate followed by aminolysis with ethylenediamine. Modification resulted in a set of novel chelating resins, which has been characterised and used in metal ion uptake experiments. These resins are highly selective towards copper(II) in acetate buffered solutions. The selectivity of the modified resins decreases in the order, Cu(II)>Cd(II)>Zn(II)>Ni(II), which is different from the Irving–Williams series. The highest affinity towards Cu(II) ions has been found for the resin modified with cyclohexene oxide, for which log Kd was 4.91 at pH 5.6.