制备了4种双磺酸丙基咪唑离子液体，用NMR表征了离子液体的结构，并通过Hammett法研究了离子液体的酸度。考察了离子液体催化甲醇和三聚甲醛合成聚甲醛二甲醚（PODE_n）的催化活性，通过单因素实验确定了最佳反应条件：反应时间为2 h、反应温度为110℃、催化剂质量分数为2%、n（甲醇）：n（三聚甲醛）为2：1。此时，三聚甲醛的转化率和PODE_3~5的选择性分别为96.91%和56.67%。研究表明，双磺酸离子液体的催化活性明显高于单磺酸离子液体，在催化合成PODE_n中更具有优势。

Four kinds of propyl imidazole disulfonate ionic liquids are synthesized,their structures are characterized by NMR spectrometer,and their acidities are determined by UV-Vis spectra.Their catalytic activities are evaluated in the synthesis of polyoxymethylene dimethyl ether (PODE_n) from methanol and trioxane.The optimal reaction conditions are determined through single factor experiments as follows:reaction time is 2 h,reaction temperature is at 110℃,mass fraction of catalyst is 2wt%,and n(methanol):n(trioxane)=2.Under these conditions,the conversion of trioxane and the selectivity to the targeted PODE_3-5 products are as high as 96.91% and 56.67%,respectively.Study shows that the catalytic activity of bis-sulfonic acid ionic liquids is significantly higher than that of sulfonic acid ionic liquid,which owns more advantageous in the catalytic synthesis of PODE_n.

张静(1995-),女,硕士研究生,研究方向为能源化工,1054670689@qq.com