Structure and characteristics of chitosan-based fibers containing chrysotile and halloysite |
| |
Authors: | I P Dobrovol’skaya P V Popryadukhin A Yu Khomenko E N Dresvyanina V E Yudin V Yu Elokhovskii S N Chvalun N N Saprykina T P Maslennikova E N Korytkova |
| |
Institution: | 1.Institute of Macromolecular Compounds,Russian Academy of Sciences,St. Petersburg,Russia;2.Karpov Institute of Physical Chemistry,Moscow,Russia;3.Institute of Silicate Chemistry,Russian Academy of Sciences,St. Petersburg,Russia |
| |
Abstract: | With the use of the methods of X-ray diffraction and electron microscopy, chitosan fibers prepared by coagulation into an
alcohol-alkali mixture are shown to possess a two-phase structure containing C- and O-type crystallites. These fibers and
composite fibers containing halloysite and Mg chrysotile nanotubes are characterized by anisotropic structure, i.e., by the
orientation of both chitosan crystallites and Mg chrysotile particles along the fiber axis. A comparison of the rates of shear
induced by passing of a polymer solution through a die and the data of rheological studies allows the conclusion that the
structuring of chitosan solution under the applied field of shear stresses and the orientation of polymer macromolecules and
filler nanotubes occur. An increase in the draw ratio during fiber spinning does not assist orientation of polymer crystallites
but, in contrast, increases surface defectiveness and leads to the nucleation of longitudinal cracks; as a result, the strength
of fibers decreases. The introduction of 5 wt % Mg chrysotile into the chitosan matrix markedly increases the mechanical characteristics
of the composite fibers owing to the reinforcing action of oriented filler nanotubes. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|