Journal of Applied Polymer Science, Vol.116, No.5, 3070-3078, 2010
Influence of the Matrix Porosity on the Synthesis and Adsorption Behavior of Dithiocarbamate Styrenic Resins Toward Zinc(II) and Cadmium(II) Ions
The dependence of the adsorption behavior toward Zn2+ and Cd2+ on the synthesis conditions of dithiocarbamate styrenic resins was investigated. We synthesized styrene-divinylbenzene copolymers with different kinds of porous structures by varying the divinylbenzene (DVB)-to-styrene ratio and the dilution degree of the monomers with n-heptane. The porous structure of these materials was characterized. The introduction of the dithiocarbamate moiety on the copolymers followed a synthetic pathway based on the nitration reaction, reduction of the nitro group to the amino one, and finally, the addition of the amino group to CS2. All of the synthesis steps were monitored by Fourier transform infrared spectroscopy. Only the addition reaction to CS2 was greatly influenced by the copolymer porosity. The effect of the dilution degree on the reaction extension was more pronounced than the effect of the DVB content. The more porous materials with higher dithiocarbamate contents adsorbed a higher amount of ions in a faster way, with Zn2+ being preferable over Cd2+ ions. The difference between the Zn2+ and Cd2+ adsorption rates was enhanced with the copolymer porosity, and also enhanced was the difference between the amounts of ions adsorbed by the copolymer; this suggested that the selectivity toward these ions could be controlled by the copolymer porous structure. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 116: 3070-3078,2010