Synthesis and chelating properties of resins with methylthiourea, guanylthiourea and dithiocarbamate groups

Three types of reactive groups: methylthiourea, dithiocarbamate and guanylt hiourea are introduced into the structure of ion-exchange/coordinating resi ns having vinylbenzyl chloride/divinylbenzene matrix. All of them contain s ulphur atom(s), and the presence of this element changes the affinity of th e resins towards the investigated cations (Cu(II). Cd(II), Zn(II), Ni(II), Pb(II), Ag(I)). It has been found that the introduction of purely coordinat ing groups leads to the decrease in the distribution coefficients for all t he investigated metal cations compared to the starting resin with amino gro ups. Introduction of dithiocarbamate groups results in a very high uptake o f the metal ions at both the pH studied. The highest affinity displayed by this resin is towards silver for which log K-d was 4.42 at pH 5.6. The poly meric resins were characterized using elemental analysis for nitrogen and s ulphur, swelling and FTIR. (C) 2000 Elsevier Science Ltd. All rights reserv ed.