Preferred uptake of Cu(II) and Cd(II) by novel pyrazole-functionalized chelating polymers

✍ Scribed by D.A. Roozemond; F. den Hond; J.B.J. Veldhuis; H. Strasdeit; W.L. Driessen

• Publisher: Elsevier Science
• Year: 1988
• Tongue: English
• Weight: 413 KB
• Volume: 24
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(88)90161-9

✦ Synopsis

The synthesis and characterization of two novel pyrazole-functionalized chelating polymers are reported. Functionalization ofp-aminomethyl substituted poly(styrene-co-divinylbenzene) was effected by treatment with 3,5-dimethyl-l-hydroxymethylpyrazole (product: LDp) and l-hydroxymethylpyrazole (product: LPz), respectively. For LDp a chelating group with one dimethylpyrazole per amine nitrogen resulted; in the case of LPz both amine hydrogen atoms were substituted by pyrazole groups. The capacities for Cu 2+ and for Cd 2÷ and their distribution coefficients appeared to be substantially larger than those for Ca :+, Co 2+, Ni 2+ and Zn 2+ for both chelating polymers in the pH range 3.5--5.5. These results were confirmed by competitive experiments between pairs of metal ions.

Regeneration (stripping) of Cu 2+-loaded LPz with strong mineral acids resulted in the decomposition of the chelating ligand, In contrast, the capacity of LDp was unchanged after several cycles of consecutive loading (with Cu 2+ ) and stripping. Sulphuric acid (0.5 M) was the most suitable stripping reagent.