纤维在NaOH-尿素体系中的溶解性能

Dissolution Property of Pulp Fibers in NaOH-urea Solvent

采用NaOH-尿素体系对针叶木浆纤维进行溶解处理,探讨了不同溶解条件对纤维溶解性能的影响,分析了经不同温度处理后未溶解纤维的形态变化,并通过傅里叶红外光谱(FT-IR)、扫描电子显微镜(SEM)和X-射线衍射(XRD)分析,对纤维和再生纤维素纤维的结构和性能进行了表征。结果表明,纤维在NaOH-尿素体系中的最佳溶解温度为-10℃,其溶解过程属于非衍生化性溶解;经碱性溶剂润胀和溶解处理后,纤维形态参数发生明显变化,纤维平均长度值变小和平均宽度值变大,其表面出现一定程度的破坏,纤维素晶型由纤维素I型向纤维素II型转变;与纤维相比较,溶解后再生纤维素的结晶度由66.77%降低到30.47%,并且转化成为纤维素II型。

NaOH-urea solvent was used to dissolve softwood pulp fibers in the study. The effects of different conditions on dissolution properties of dissolving pulp fibers were investigated. The morphology changes of undissolved fiber at different temperatures were analyzed. And the structure and properties of raw material fibers and regenerated cellulose fibers were characterized by using the FT-IR, SEM and XRD. The results indicated that the optimal dissolving temperature of pulp fibers in NaOH-urea solvent system was - 10℃, and its dissolution process was non-derivatization dissolution. Fiber morphology parameters changed significantly after alkaline solvent swelling and dissolution treatment, the value of the average fiber length became smaller and width value became larger, the fiber surface was damaged in a certain degree, and cellulose crystal transformed from cellulose I to cellulose II. Compared with the raw material fibers, regenerated fibers, crystallinity decreased from 66. 77% to 30. 47%.