Long LI, Meng-fan WANG, Na JIAO, Liang-hua XU, Wei-yu CAO. The Effect of the Force Field on the Crystalline and Orientation Structure of PAN Nascent Fiber during Dry Jet Wet-Spinning and Wet-Spinning Processes[J]. Polymer Bulletin, 2014,27(1):43-58.
Long LI, Meng-fan WANG, Na JIAO, Liang-hua XU, Wei-yu CAO. The Effect of the Force Field on the Crystalline and Orientation Structure of PAN Nascent Fiber during Dry Jet Wet-Spinning and Wet-Spinning Processes[J]. Polymer Bulletin, 2014,27(1):43-58.DOI:
Wide angle X-ray diffraction (WAXD) was applied to study the Hermann orientation factor and crystallinity of PAN nascent fiber obtained by dry jet wet-spinning and wet-spinning methods
respectively. Based on the azimuthal scan results
it was indicated that with the increasing of shear rate and drawing ratio
the Hermann orientation factor of the nascent fiber gradually improved. At the same shear rate and drawing ratio
compared with the nascent fiber made by dry jet wet-spinning
the orientation factor of the nascent fiber produced by wet spinning is higher. During the dry jet wet- spinning process
the crystallization was occurred under weak stretching since the drawing force was focus on the soft part in air layer. Therefore
the Hermann orientation factor was reduced. However
in the wet-spinning process
the crystallization occurred immediately after extrusion
the drawing force induced the increasing of the orientation for crystalline region. The model for the evolution of the aggregation state of PAN molecular chains was proposed.
关键词
PAN初生纤维干湿法湿法晶区取向结构
Keywords
PAN nascent fiberDry jet wet-spinningWet-spinningHermann orientation factor