Synthesis of new side-chain polyrotaxanes via free radical polymerization of a water-soluble semi-rotaxane monomer consisting of 2,6-dimethyl-β-cyclodextrin and 3-O-(11-acryloylaminoundecanoyl)cholic acid

The synthesis of a new water-soluble semi-rotaxane monomer consisting of threaded 2,6-dimethyl-β-cyclodextrin on a 3-O-(11-acryloylaminoundecanoyl)cholic acid guest component is described. This new monomer complex was polymerized in water as a solvent in the presence of a free radical redox initiator, yielding a side-chain polyrotaxane. Two main fractions of the resulting polymeric product were isolated by extraction with water. About 50 wt.-% of the polymer material contains approximately 40 mol-% of noncovalently anchored cyclodextrin with regard to the amount of side-chain units. This fraction is not soluble in water. Additionally, a smaller water-soluble fraction with a significantly lower degree of polymerization was isolated bearing nearly one cyclodextrin on each side-chain unit.