纤维素在离子液体中均相酰化反应动力学

Kinetics of cellulose acylation in ionic liquid

以离子液体1-烯丙基-3-甲基咪唑氯盐（AmimCl）为反应媒介,以微晶纤维素为原料,研究了离子液体中纤维素与酸酐均相酰化反应的动力学,通过实验考察了纤维素初始羟基浓度（0.21~0.85 mol.L-1）及反应温度（353~373 K）对酰化反应速率的影响。结果表明,随着离子液体中纤维素羟基浓度的增大和反应温度的升高,纤维素酰化反应的速率都呈增大趋势。通过实验得到了纤维素均相酰化反应的动力学方程,纤维素乙酐酰化及乙酐、丁酐混合酸酐酰化反应的反应级数均为1,表观活化能分别为19.03 kJ.mol-1和20.04 kJ.mol-1。

Using ionic liquid 1-allyl-3-methylimidazolium chloride（AmimCl）as reaction media,microcrystalline cellulose as raw material,the kinetics of homogeneous acylation of cellulose in ionic liquid was studied.The effect of initial cellulose hydroxyl concentration from 0.21 mol·L-1 to 0.85 mol·L-1 and temperatures from 353 K to 373 K on the acylation rate were measured.Results showed that the acylation rate increases with increasing initial cellulose hydroxyl concentration and reaction temperatures.The reaction kinetic equations were determined based on the experimental data.The reaction order for both acylation by acetic anhydride and by mixture of butyric anhydride and acetic anhydride is first-order,and their apparent activation energies are 19.03 kJ·mol-1 and 20.04 kJ·mol-1 respectively.