State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu 610065, China.
State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu 610065, China.
Carbohydr Polym. 2014 Nov 26;113:83-90. doi: 10.1016/j.carbpol.2014.07.005. Epub 2014 Jul 11.
In this paper, we demonstrated that acidic ionic liquids (ILs) can be used as "quasi-homogeneous" catalysts for the efficient acetylation of cellulose. Unlike existing techniques that use large amount of ILs as solvent to dissolve and acetylate cellulose, a small amount of acidic ILs was used as catalyst in this study to overcome the low efficiency associated with relatively high viscosity and costs of ILs during homogeneous acetylation. Fully substituted cellulose acetate with a conversion of 88.8% was obtained by using only 9 mol% IL 1-vinyl-3-(3-sulfopropyl) imidazolium hydrogen sulfate as catalyst, which is much higher than that of common commercialized solid acid catalysts. The degree of substitution and solubility of the obtained cellulose acetate can be facilely controlled by varying the concentration of ILs and reaction time. The dual function of swelling and catalyzing of acidic ILs for the acetylation of cellulose is responsible for the excellent catalytic performance.
在本文中，我们证明了酸性离子液体（ILs）可用作“准均相”催化剂，以有效地乙酰化纤维素。与现有的技术不同，这些技术使用大量的 ILs 作为溶剂来溶解和乙酰化纤维素，在这项研究中，少量的酸性 ILs 被用作催化剂，以克服在均相乙酰化过程中与 ILs 的相对高粘度和高成本相关的低效率。仅使用 9 mol%的 IL 1-乙烯基-3-(3-磺丙基)咪唑𬭩硫酸氢盐作为催化剂，即可获得转化率为 88.8%的完全取代的纤维素醋酸酯，这远高于常见的商业化固体酸催化剂的转化率。通过改变 ILs 的浓度和反应时间，可以方便地控制所得纤维素醋酸酯的取代度和溶解度。酸性 ILs 对纤维素乙酰化的溶胀和催化双重功能是其优异催化性能的原因。
