木纤维素浆粕在1-丁基-3-甲基咪唑氯盐中的溶解特征

Dissolution mechanism of wood pulp in[BMIM]Cl

为探究1-丁基-3-甲基咪唑氯盐([BMIM]Cl)对木纤维素浆粕的溶解能力,讨论其溶解纤维素的过程及条件,首先采用偏光显微镜和扫描电子显微镜表征再生纤维素的形貌变化,采用傅里叶红外光谱测试再生纤维素的化学结构变化。其次,在不同溶解条件下将木浆粕纤维溶解在[BMIM]Cl离子液体中,为了得到最佳溶解条件,采用X射线衍射仪、热重分析仪对再生纤维素进行表征,研究搅拌速率、溶解温度以及3种前处理方式对纤维素在[BMIM]Cl离子溶液中溶解后的聚合度、降解度和结晶度的影响。结果表明:木纤维素在[BMIM]Cl离子溶液中的最佳溶解条件为搅拌速率100 r/min、溶解温度80℃,超声波处理1 h,再生纤维素聚合度948,降解度5.77%,结晶度67.24%。

In order to investigate the dissolution feasibility of wood pulp fiber in ionic liquid,and to discuss the process and conditions of dissolving cellulose,firstly,the morphological changes of regenerated cellulose were characterized by polarizing microscope and scanning electron microscope,and the chemical structure of regenerated cellulose was revealed by fourier transform infrared spectroscopy.Then,wood pulp was dissolved in[BMIM]Cl ionic liquid under different dissolution conditions.In order to obtain the optimal dissolution conditions,the regenerated cellulose was characterized by X-ray diffractometer and thermogravimetric analyzer to reveal the effects of stirring rate,dissolution temperature and pretreatment methods on the degree of polymerization,degradation and crystallinity of cellulose dissolved in[BMIM]Cl ionic liquid.The results show that the best dissolution conditions for wood pulp in[BMIM]Cl ionic liquid are agitation rate of 100 r/min,dissolution temperature of 80℃,and ultrasonic treatment for 1 h,the degree of polymerization and crystallinity of regenerated cellulose are 948 and 67.24%,the degradation degree is 5.77%,respectively.