作　　者： ; ; ; ; (周冠成）;

机构地区： 南京林业大学轻工科学与工程学院江苏省制浆造纸科学与技术重点实验室

出　　处： 《高分子学报》 2014年第4期491-498,共8页

摘　　要： 以绿色环保的碱脲体系溶解天然纤维素,并采用高压静电喷雾法制备再生纤维素微球.主要探讨了表面张力、静电力、溶液黏度和推进速度对微球形态和粒径的影响,并用扫描电镜、红外光谱和X射线衍射图谱进行了表征.结果表明,溶液表面张力的降低会使得微球粒径减小,其中粒径减小的程度与溶剂体系的挥发程度和溶液的均一性相关;同时,微球粒径随着静电力的增大呈减小趋势,而随着推进速度增加粒径呈单调上升趋势;微球形态与溶液黏度密切相关,当溶液黏度下降时,微球球形度下降,由球形变为楔形甚至带状结构,并且平均粒径有所减小,粒径分布增大.此外,再生后的纤维素微球具有良好的多孔性结构,纤维素化学性质没有发生改变,但晶型从纤维素Ⅰ转变为纤维素Ⅱ. Regenerated cellulose microspheres were prepared by means of electrospraying technology from environmental-friendly NaOH/urea aqueous system. The effects of processing parameters including surface tension, electrostatic force, solution viscosity and flow rate on the morphology and size of cellulose microspheres were investigated. The properties of microspheres were characterized by SEM, FTIR and XRD. The results indicate that microspheres with small particle size were prepared from cellulose solutions with low value of surface tension. The particle size is related to the homogeneity of solution and the volatility of solvent system. There is an obvious decrease in the particle size with an increase in the electrostatic force, while the particle size increases with increasing flow rate. The shape of microspheres depends on solution viscosity significantly. With decreasing solution viscosity, the shape of particles may change from sphere to wedge and even strip. Meanwhile ,the particle size decreases and size distribution increases. In addition, the regenerated cellulose microspheres have good porosity. The molecular structure of cellulose remains but the crystal structure changes from cellulose I into cellulose Ⅱ in the process of dissolving and regenerating.

关 键 词： 静电喷雾 碱脲体系 纤维素微球 表面张力 静电力 溶液黏度

领　　域： [理学] [理学]