不同碱/尿素水体系处理对纤维的影响

Effects of the pretreatment using different alkali/urea aqueous systems on the properties of fiber

利用不同碱/尿素水体系对纤维进行了预处理.探讨了相同摩尔比时不同碱(NaOH、LiOH和KOH)/尿素水体系对纤维润胀性能的影响;同时,还采用光学显微镜、纤维质量分析仪和扫描电镜等对处理前后的纤维形态进行了分析,测定了处理前后纤维聚合度的变化情况,并使用傅里叶红外光谱对其进行了结构表征.研究结果表明:NaOH、LiOH和KOH等3种碱/尿素水体系均可提高纤维的润胀性能,经处理后3种纤维的纤维形态和各形态参数均发生了不同程度的变化,聚合度也均有降低.其中,NaOH/尿素水体系对纤维的润胀性能、纤维形态以及纤维聚合度的影响最大;经3种碱/尿素水体系处理后,纤维的分子结构并没有发生明显变化,但其结晶区却被部分破坏,并且Na纤维的结晶结构可能向纤维素Ⅱ转变.

The fiber was pretreated by using different alkali/urea aqueous systems, and the effects of the different alkali （NaOH,LiOH and KOH）/urea aqueous systems in same mole ratio on the swelling property of fiber was discussed. At the same time, the changes of the liber morphology before and after pretreatment were analysed by using the optical micro-scope, fiber quality analyzer and SEM,the changes of the degrees of polymerization of these fibers were determined,and the Fourier-IR spectrum analysis was conducted for the charac-terization of fiber structure. The results showed that the alkali/urea aqueous systems of NaOH,LiOH and KOH all could improve the swelling properties ofthe fiber, and the fiber morphology and the morphology parameters of three kinds of treated fibers had changes invarying degrees,and the degrees of polymerization of these fibers were all decreasing. Among these, the effects of NaOH/urea aqueous system on the swelling property, morphology and the degree of polymerization of fiber were all most prominent. After treatment in three kinds of alkali/urea aqueous systems, the molecular structures of treated fiber had no obvious change,but its crystalline regions were partially destroyed, with the crystalline structure of Na-fiber transformed to cellulose Ⅱ .