PREPARATION OF SELF-ASSEMBLED CHITIN NANOFIBERS AND THEIR COMPOSITES WITH CELLULOSE DERIVATIVES

摘要

Of the many kinds of polysaccharides, chitin is one of the most abundant polysaccharides. The author found that an ionic liquid, 1-allyl-3-methylimidazolium bromide (AMIMBr), dissolved chitin in concentrations up to～5% (w/w) and mixtures of the higher amounts of chitin with AMIMBr gave ion gels. When the ion gel of chitin with AMIMBr was immersed in methanol, followed by sonication, the regenerated chitin formed nanofibers according to self-assembling procedure.The SEM image of the dispersion showed morphology of the nanofibers in with ca.20-60 nm in width and several hundred nanometers in length. On the basis of the above studies, the preparation of chit in nanofiber/ carboxymethyl cellulose (CMC) composite films was investigated by their electrostatic interaction. CMC is one of the representative cellulose derivatives and has acidic nature. The CMC films, which were prepared by casting technique, were immersed in the aforementioned chitin nanofiber dispersions with methanol, followed by centrifugation to obtain the desired composite films. The amounts of the absorbed chitin nanofibers on the films were calculated by the weight increases after the above compatibilization procedure. The SEM and IR of the products suggested the presence of chitin nanofibers on the films. The mechanical properties of the composite films were evaluated by tensile testing, which suggested the reinforcing effect of chitin nanofibers present on the CMC films.