Effect of preparation conditions for poly(ethylene glycol)/cyclodextrin polyrotaxane on modes of end-capping reactions and decomposition of the yielded polyrotaxane

摘要

PEG/CD polyrotaxane was prepared under seven conditions with different temperature and presence/absence of different types of end-capping molecules (adamantanamine or diphenylethylamine). The polyrotaxane was synthesized even without the addition of end-capping molecules, via undesirable esterification between terminal carboxyls of PEG and hydroxyls in CDs. Decomposition behavior of the obtained polyrotaxanes were characterized by means of gel permeation chromatography (GPC), ~1H NMR and alkaline hydrolysis examination. The GPC results suggested that the ester-capped polyrotaxanes were found to be decomposed over months at room temperature and humidity.