Effect of the draw ratio in dry jet-wet spinning on aromatic copolysulfonamide fibers  

作　　者：Jian-Ning Wang Yu-Mei Zhang Xiao-Yun Li 

机构地区：[1]State Key Laboratory for Modification of Fibers and Polymer Materials,College of Material Science and Engineering,Donghua University,Shanghai 201620,China [2]Shanghai Synchrotron Radiation Facility,Shanghai Advance Research Institute,Chinese Academy of Sciences,Shanghai 201210,China

出　　处：《Nuclear Science and Techniques》2020年第7期1-11,共11页核技术（英文）

基　　金：financially supported by the National Natural Science Foundation of China(Nos.11079015,51273039 and 11705269);the Fundamental Research for the Central Universities(No.CUSF-DHD-2016044);Shanghai Sailing Program(No.17YF1423800)。

摘　　要：Aromatic copolysulfonamide(co-PSA)fiber produced via wet spinning exhibits poor mechanical properties.Hence,dry jet-wet spinning was introduced to prepare the co-PSA fiber.Dry jet-wet spinning exhibits the advantage of positive stretching to the extruded fiber before coagulation.The fibers were spun at different jet draw ratios and second draw ratios and were examined for scanning electron microscopy,mechanical properties,sound velocity,small-angle X-ray scattering(SAXS),and wide-angle X-ray scattering(WAXS).The results revealed that all the fibers exhibited a uniform and dense structure and nearly round cross section at different drawing conditions.The strength and orientation of the fiber increased slightly as the jet draw ratio was increased to the second draw ratio of 2.0.Furthermore,the fibers formed a periodic ordered structure along the fiber axis.However,the strength of the fibers decreased significantly when the jet draw ratio continued to increase and the second draw ratio decreased year-on-year to maintain the total draw ratio at11.0.Additionally,the fibers exhibited lower orientation because the molecular chain segments could not continue to extend and orient even at larger jet draw ratios,and thus they could not be further well-stretched at subsequent lower stretching ratios.Meanwhile,the periodic ordered structure disappeared and more content of entanglement structure existed in the fibers.During the heat drawing process,the results of SAXS and WAXS indicated that the better ordered molecular chain segments within the fiber were easier to arrange and reconstruct to significantly improve the content of crystalline and mesophase structures in the fibers.Hence,after the heat drawing process,the strengths of co-PSA-H2 and co-PSA-H3 fibers increased to more than 620 MPa,which is significantly higher than those of commercialized fibers and fibers reported in extant studies.

关 键 词：fibers SPINNING STRETCHING 

分 类 号：TQ340.64[化学工程—化纤工业]