Polymerization of β-cyclodextrin with 1,2,3,4-butanetetracarboxylic dianhydride: Synthesis, structural characterization, and bisphenol A adsorption capacity

Water-soluble and water-insoluble β-cyclodextrin polymers (β-CDPs) were prepared from β-CD using 1,2,3,4-butanetetracarboxylic dianhydride (BTCA) as a cross-linker. The structures of the synthesized water-soluble and water-insoluble β-CDPs were characterized in detail using FT-IR, solution- and solid-state NMR, and 1H diffusion-ordered spectroscopic techniques. The water solubility of β-CDP was dependent on the reaction temperature as well as the initial feed ratio of β-CD and BTCA. The BTCA content and the ratio of BTCA molecules cross-linked and grafted to β-CD were also found to influence the water solubility of the polymers. Insoluble β-CDPs were effective in adsorbing bisphenol A (BPA) from aqueous media, with this absorption being highest in materials of low BTCA content, which corresponds to material of high β-CD content per unit mass of β-CDP.