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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 chemical structure of cellulose acetate (CA_ (Homo)) prepared by homogeneous reaction in ionic liquid and the heterogeneous reaction of cellulose acetate (CA_ (Hete)) were studied. The effects of different chemical structure on the cellulose (Homo), CA_ (Homo) and CA_ (Hete) were better than that of CA_ (Hete) , The order of acetyl substitution in CA Homo is C-6> C-3> C-2, and the substitution order of acetyl in CA Hete is C-3> C-2> C-6. At the same time, the crystallization behavior, solubility and thermal properties of Homo and CA_ (Hete) were studied. The results showed that the different chemical structures had little effect on the macroscopic properties of CA. Both Homo and CA_ The amorphous structure is soluble in polar organic solvents and has similar glass transition temperature and thermal stability. Therefore, the CA homogeneously prepared by ionic liquid has similar physical properties to the CA prepared by the current heterogeneous method, however, Homogeneity of CA structure prepared by homogeneous method is better.