|Tubular Polymers: Syntheses and Properties
Department of Materials Science and Engineering, Nagoya Institute of Technology, Showa-ku, Nagoya, Japan
Nippon Gomu Kyokaishi,(2009),82(6),264-271 General Review in Japanese
A tubular structure, which has highly anisotropic space, causes unique character and functionality. This review article deals with syntheses and some properties of polymer molecules having tubular structures. There are summarized three synthetic approaches (A, B, and C) for such polymers. A) Layered bridging of macrocyclic compounds: A cyclodextrin tube is easily prepared with the aid of the sledding polymer template and used as a host for an alkyl chain or a linear polymer. The tubular oligomers of calixarenes with oxyethylene linkages are examined for shuttling of a metal cation. The well-defined tubular polymers have not yet been prepared from calixarene and crown ether. B) Coupling of two wagon-head molecules: A couple of ladder silsesquioxanes are interconnected with each other through hydrosilylation, however, producing an imperfect tube. C) Removal of the internal core from a columnar core-shell molecule: The columnar alignment of the dendrimer by linking the tin-porphyrin core is followed by cross-linking the outer allylic groups to fix the column structure. Then, the porphyrin core is removed by the ester exchange reaction to give the tubular molecule.
Tubular Polymer, Cyclodextrin, Calixarene, Crown Ether, Silsesquioxane, Dendrimer