Effects of Coagulation Conditions on Tensile Properties of Regenerated Cellulose Fibers

The effects of coagulation conditions on tensile properties of the regenerated cellulose fibers prepared by wet-spinning from NaOH/thiourea/urea(8∶6.5∶8 by weight)aqueous solvent were investigated by tensile tester,X-ray diffraction(XRD),and scanning electron microscope(SEM).The results show that the tensile properties of the as-spun fibers change with the coagualtion concentration,temperature,and time.When the spinning solution is coagulated in 10% H2SO4/12.5% Na2SO4 aqueous solution,the as-spun fibers have a typical structure of cellulose II,a circular cross-section,and homogeneous morphological structure.

LiOH复合溶剂体系直接溶解法制备新型再生纤维素纤维

首次发现纤维素可快速溶解于LiOH/硫脲/尿素水溶液中。通过偏光显微镜进行了观察,纤维素在新溶剂体系中的溶解过程,并通过湿法纺丝技术在10%(质量分数)H2SO4/12.5%(质量分数)Na2SO4的凝固浴中凝固再生纤维素,成功制备了新型纤维素纤维。再生纤维的结构通过扫描电镜和广角X射线衍射进行了表征,研究发现,这种再生纤维分子量较高,形态上具有圆形的截面和光滑的表面,结构上属于典型的纤维素Ⅱ,并具有较高的结晶度。这些形态结构特性保证了新纤维具有较好的力学性能。