No abstract

The present paper focuses on (i) a new synthetic methodology to prepare vinyl ether‐based synthetic glycoconjugates (glycopolymers) with well‐controlled structure, and on (ii) the application of glycopolymers bearing modified disaccharide residue as thermotropic liquid crystalline (LC) materials. Two vinyl ethers (VEs) having pendant glucose residues with their hydroxyl functions protected by acetyl and isopropylidene groups, respectively, were found to undergo living cationic polymerization initiated by a HI/ZnI2‐initiating system. Deprotection of the resultant monodisperse polymers led to water‐soluble polymers bearing a pendant glucose residue. Sequential living block copolymerization of glucose‐containing VE and alkyl VE, and subsequent deprotection afforded an amphiphilic block copolymer of well‐controlled structure. Transmission electron microscopic observation of its cast thin film revealed microphase‐separated surface morphologies that varied with varying segment composition ratio. A VE substituted with a heptadecanoated cellobiose pendant was independently prepared, and was cationically polymerized to give a thermotropic LC polymer. From X‐ray analysis, the mesophase was assigned to a discotic columnar in type, in which each main chain, extended due to the steric repulsion between the neighboring bulky pendants, was surrounded by three discotic columns.

A series of 2,3-O-carboxymethylcelluloses (CMC's), which are regioselectively substituted at the C-2 and C-3 position, were prepared and their water solubility was examined. It was found that the lower limit for the degree of substitution (DS) value of water-soluble 2,3-0-CMC is about 0.3. This value was almost the same as that of CMC prepared in a slurry of isopropyl alcohoVwater with isopropyl chloroacetate and sodium hydroxide, showing that the uniform alkylation is rather important to convert cellulose into watersoluble derivatives.