均相与非均相法合成的纤维素乙酸酯结构与性能的比较研究  

Comparative Study on Structure and Properties of Cellulose Acetate Synthesized by Homogeneous and Heterogeneous Acetylation

作　　者：吕玉霞[1] 张金明[2] 王飞俊[1] 邵自强[1] 张军[2] 

机构地区：[1]北京理工大学材料学院,北京100081 [2]中国科学院化学研究所,北京100190

出　　处：《高分子学报》2016年第3期324-329,共6页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号51303013);北京理工大学基础研究基金(基金号20130942004)资助项目

摘　　要：研究了离子液体中均相反应制备纤维素乙酸酯(CA_(Homo))与非均相反应制备纤维素乙酸酯(CA_(Hete))的化学结构,进而比较了化学结构差别对纤维素乙酸酯性能的影响.均相与非均相法制备的CA化学结构存在显著差异,CA_(Homo)相比CA_(Hete)具有更好的均匀性,且CA_(Homo)和CA_(Hete)的取代基分布不同,CA_(Homo)的乙酰基取代顺序为C-6>C-3>C-2,CA_(Hete)的乙酰基取代顺序为C-3>C-2>C-6.同时对CA_(Homo)和CA_(Hete)的结晶行为、溶解性和热性能进行研究,结果表明,不同化学结构对CA的这些宏观性能影响较小,CA_(Homo)和CA_(Hete)均为无定型结构,可溶解于极性有机溶剂中,玻璃化转变温度和热稳定性相近.因此,通过离子液体均相制备的CA与现有非均相法制备的CA具有相似的物理性能,但均相法制备的CA结构均匀性更好.The structure and properties of cellulose acetate（ CA） prepared by homogeneous acetylation in ionic liquids（ CAHomo） and heterogeneous acetylation（ CAHete） were investigated. The characterizations of CAs such as molecular weight,molecular weight distribution,degree of substitution（ DS）,distribution of acetyl groups and the partial DS at C-2,C-3 and C-6 were determined by GPC,^1H- and13C-NMR. The DS of CAHomo and CAHetewas about 2. 50 calculated by^1H-NMR. The distribution of acetyl groups calculated by13C-NMR was C-6 〉C-3〉 C-2 for CAHomoand C-3〉 C-2〉 C-6 for CAHete,respectively. In addition,the structure of CAHomohad better uniformity than that of CAHete. Subsequent property studies showed that the chemical structure differences of CAs had tiny effect on their properties,such as crystallinity,solubility and thermal properties. CAHomoand CAHetewere all amorphous structure,and they had better solubility in polar organic solvents. The glass transition temperature and thermal stability were similar for these CAs samples. Therefore,CAHomosynthesized by homogeneous acetylation in ionic liquids had similar physical properties as those of CAHeteprepared by heterogeneous acetylation,but the structure of CAHomohad better uniformity than that of CAHete.

关 键 词：纤维素乙酸酯 结构表征 乙酰基分布 结构与性能 

分 类 号：O636.1[理学—高分子化学]