Synthesis and characterization of a polyrotaxane consisting of #beta#-cyclodextrins and a poly(ethylene glycol)-poly(propylene glycol) triblock copolymer

摘要

A polyrotaxane in which many #beta#-cyclodextrins (#beta#-CyDs) are threaded onto a triblock copolymer of poly(ethylene glycol) (PEG) and poly(propylene glycol) (PPG) capped with fluorescein-4-isothiocyanate (FITC) was synthesized as a model of stimuli-responsive molecular assemblies for nanoscale devices. #beta#-CyDs threaded onto the triblock copolymer enhance the solubility of the polyrotaxane and presumably contribute to the prevention of aggregation between PPG segments. The interaction of #beta#-CyDs with a terminal FITC moiety was observed to be significant at 10deg C, however, with increasing temperature, the interaction of #beta#-CyDs with a PPG segment becomes prominent. From these results, it is concluded that the majority of #beta#-CyDs move toward the PPG segment with increasing temperature although some #beta#-CyDs may reside on PEG segments.