氯化铵改性Lyocell纤维的制备及其热处理

研究了不同NH4Cl含量的纤维素／NMMO·H2O溶液的流变性能，在此基础上制备了NH4Cl改性Lyocell初生纤维，并探讨了NH4Cl添加量及后续热处理对纤维结构与性能的影响。结果发现：随着NH4Cl添加量的增加，纤维素溶液体系的表观黏度、结构化程度、表观相对分子质量增加而表观相对分子质量分布变窄。结合广角X-射线衍射和双折射分析结果还发现：对Lyocell纤维采用NH4Cl改性或进一步结合热处理，都可以有效提高纤维的结晶度和取向度，完善最终纤维的聚集态结构。对纤维的性能分析结果表明：在本研究条件下，当NH4Cl添加量为5％时，经适当条件热处理后，最终得到Lyocell纤维断裂强度7．21cN／dtex、初始模量92．6cN／dtex、干热收缩率小于0．8％，并且蠕变率也有一定的下降．

Preparation and Heat Treatment of Lyocell Fiber Modified by Ammonium Chloride

The effect of ammonium chloride(NH_4Cl) content on the rheological behaviors of cellulose/ NMMO·H_2O solution and on the structure and properties of the resultant Lyocell fiber were investigated. Moreover,the heat treatment of as-spun NH_4C1 modified Lyocell fiber were studied.It was found with the increasing NH_4Cl content,the apparent viscosity,structural degree and apparent relative molecular weight of the cellulose solution were increased while molecular weight distribution became narrow.The results from WAXD and birefringence showed that the crystallinity and orientation of Lyocell fiber could be improved by both the modification using NH_4Cl and the further heat treatment.In case that never dried as-spun Lyocell modified by 5%NH_4C1 was heat-treated under an appropriate condition,the tensile strength and initial modulus of resultant Lyocell fiber could reach 7.21 cN/dtex and 92.6 cN/dtex, respectively,and its dry heat shrinkage was lower than 0.8%.Furthermore,its creep ratio could also be improved.