| Abstrakt: |
The interplanar spacings and unit cell parameters of CIβ crystallites are not constant but vary within a limited range of values. Such structural changes are caused by the distortion of the crystal lattice. It was shown that the paracrystalline fraction of crystallites introduces the main contribution to the distortion of the crystalline lattice. The decrease in the content of this fraction led to the reduction in distortion parameters, interplanar spacings, and the volume of the crystalline unit cell. As a result, the undistorted crystalline unit cell of CIβ macrocrystals can be proposed with the following parameters: ao= 0.772 nm, bo= 0.815 nm, co=1.040 nm, γo =96.5o. In addition, the specific volume and specific gravity of such macrocrystals, Vc,o = 0.604 cm³/g and Gc,o = 1.655 g/cm³ were calculated. It was also found that by knowing the content of the paracrystalline fraction in the CIβ crystallites, one can predict several important properties of cellulose. [ABSTRACT FROM AUTHOR] |
