Polymerization of beta-cyclodextrin with maleic anhydride and structural characterization of the polymers

beta-Cyclodextrin (beta-CD) polymers were prepared by cross-linking beta-CD with maleic anhydride (MA) in anhydrous N,N-dimethyl formamide (DMF) in th e presence of NaH. The weight-average molecular weight (M-w) and the chemic al structure of the polymers were determined using high performance size ex clusion chromatography (HPSEC) with refractive index (RI) and multiangle la ser-light scattering (MALLS) detectors, and H-1 NMR spectroscopy. The molec ular weight of the polymer increased as the reaction temperature was raised . With a reaction of 4 h at 130 degrees C at a molar ratio of 1:7:7 for bet a-CD:NaH:MA, the reaction products were water-insoluble, and contained majo r polymer fractions with M-w greater than 200 kDa. Smaller and water-solubl e polymer fractions were produced at 100 degrees C or lower reaction temper ature. H-1-NMR spectra revealed that the CD polymers contained both mono- a nd diesters of butenedioic acid, and diesters became prevalent as the react ion time and temperature were raised. (C) 2000 Elsevier Science Ltd. All ri ghts reserved.