Reorientation of crystalline and noncrystalline regions in regenerated cellulose fibers and films tested in uniaxial tension |
| |
| Authors: | Wolfgang Gindl Moritz Reifferscheid Klaus J. Martinschitz Peter Boesecke Jozef Keckes |
| |
| Affiliation: | 1. Department of Materials Science and Process Engineering, University of Natural Resources and Applied Life Sciences, Vienna, Austria;2. Erich Schmid Institute of Materials Science, Austrian Academy of Sciences and Institute of Metal Physics, University of Leoben, Leoben, Austria;3. European Synchrotron Radiation Facility, Grenoble, France |
| |
| Abstract: | The orientation of molecular chains in regenerated cellulose films and fibers was characterized using in situ wide‐angle X‐ray diffraction and birefringence measurements coupled with tensile tests. Generally, an increase in the degree of preferred orientation in the direction of applied strain was observed during testing. For both types of specimen this relationship was clearly linear, irrespective of whether the volume‐averaged preferred orientation or the orientation in the crystalline and noncrystalline regions was considered. Interestingly, the rate of change in orientation induced by external strain was significantly higher for noncrystalline regions when compared with that of crystalline regions. This difference was more pronounced for cellulose fibers when compared with films. Upon the reversal of straining in cellulose films until zero stress, the degree of orientation diminished in a linear fashion. However, a large part of the orientation, both crystalline and noncrystalline, induced by tensile straining remained permanent and increased further when straining was resumed. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 297–304, 2008 |
| |
| Keywords: | cellulose fibers films mechanical properties orientation |
|
|
