Polymerisation of β-cyclodextrin with succinic anhydride. Synthesis, characterisation, and ion flotation of transition metals

β-Cyclodextrin (β-CD) polymers were prepared by cross-linking β-CD with succinic anhydride (SA) in anhydrous N,N-dimethylformamide (DMF) in the presence of NaH. The weight-average molecular weight (M_w) and the chemical structure of the polymers were determined using high performance size exclusion chromatography (HPSEC) with refractive index (RI) detector, and ¹H NMR spectroscopy. The molecular weight of the polymer increased with reaction temperature. ¹H NMR spectra revealed that the CD polymers contained both mono- and diesters of butanodioic acid. In the case of fractions with higher molecular weight, about two diester moieties groups are linkages for CD molecules. Results of competitive ion flotation of copper(II) obtained with the use of nonylphenol polyoxyethyl glycol ether as an non-anionic surfactant and β-CD polymers as complexation agent, show that the removal of metal decreases with higher molecular mass of β-CD polymers. The competitive ion flotation of Cu²⁺, Zn²⁺, and Cd ²⁺ cations from diluted aqueous solutions in the presence β-CD polymers is presented.