Preparation and properties of polyrotaxane from α-Cyclodextrin and Poly (ethylene glycol) with Poly (vinyl alcohol)

Poly (ethylene glycol) makes a reversible complex inclusion compound with α– cyclodextrin. Meanwhile, cyclodextrins (CDs) are a series of natural cyclic oligosaccharides composedof 6, 7, or 8 D(+)-glucose units which are connected through α-1,4-bondings namely α-, β-, or γ-CD, respectively. Variousmolecules can be fitted into the cavities of CDs to form supramolecular inclusion complexes, which have been widelystudied as models to explain mechanism of the molecularidentification. The current work aims to prepare and examine regularly shaped, hexagonal complexes of α-CD using PEG inthe presence of PVA. The sonic energy was found to have major effect on the formation of discrete size microcrystals forcomplex inclusion compounds of PEG-α-CD in PVA solution. Both the time and the sonic energy at room temperature(250C) were effective factors of this process. Right concentration of PVA could facilitate the formation of discrete hexagonal microcrystals