Journal of Polymer Science Part A: Polymer Chemistry, Vol.49, No.10, 2199-2209, 2011
Polyrotaxane Derivatives. II. Preparation and Characterization of Ionic Polyrotaxanes and Ionic Slide-Ring Gels
Four types of ionic polyrotaxane (PR) derivatives, that is, carboxymethylated, sulfoethylated, diethylaminoethylated, and trimethylammoniohydroxypropylated PRs, were successfully prepared starting from the same PR consisting of poly(ethylene glycol) as an axis and alpha-cyclodextrins as ring molecules. The structures of the ionic PR derivatives were analyzed by H-1 and C-13 nuclear magnetic resonance (NMR), attenuated-total reflection Fourier transform-infrared, and colloidal titration. Degrees of substitution of the ionic PRs were calculated from results of H-1 NMR and colloidal titrations; both sets of results satisfactorily agreed. Cross-linking of sulfoethylated and quaternized PRs yielded ionic slide-ring gels carrying sulfoethyl and quaternary ammonium groups on the mobile cross-links, respectively. The former gel showed intriguing phenomena, including a large degree of swelling of up to 1147, drastic change in its swelling ratio by the presence of electrolyte and bending under a moderate applied electric field (7 V/cm). (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 2199-2209, 2011