Forum 05/22/2003

“Fabrication of Polymer Materials from their Cyclodextrin Inclusion Complexes”

Min Wei, Research Assistant –┬áNorth Carolina State University

Cyclodextrins are cyclic compounds consisting of six to eight glucose units, which are called alpha-, beta-, and gamma-cyclodextrin, respectively. They are known to form inclusion complexes with various low-molecular-weight compounds, ranging from nonpolar aliphatic molecules to polar amines and acids. In this decade, many published work have shown that cyclodextrin (CD) can form molecular assembly-inclusion complex (IC) with not only small molecules but also various high molecular polymers. In these tubular inclusion complexes, the guest polymer chains occupy narrow cylindrical channels (Diameter ~ 0.5-1.0nm) created by the stacking of cyclodextrins in the crystalline lattice. As a consequence, the included guest polymer chains are constrained to assume highly extended conformations and are generally segregated from neighboring included polymer chains by the channel walls of the host crystalline lattice. When these complex crystals are treated to remove the host, but without damaging or dissolving the guest polymers, they are forced to coalesce into a polymer solid retaining extended conformational chains confined by cyclodextrin cylinder. Our recent works have demonstrated that polymers coalesced from their cyclodextrin inclusion complexes have distinguished properties from polymers in bulk.