Influence of Carboxylate Anions on Phase Behavior of Choline Ionic Liquid Mixtures

Molecules

PeterS. Schulz¹  Peter Wasserscheid¹  Mikhail Gantman²  Gunnar Nurk³  Kaija Põhako-Esko⁴  Fred Elhi⁴  Alvo Aabloo⁴ 

[1] Department of Chemical and Biological Engineering (CBI), Institute of Chemical Reaction Engineering, University of Erlangen-Nuremberg, Egerlandstraße 3, 91058 Erlangen, Germany;Forschungszentrum Jülich GmbH, Helmholtz Institute Erlangen-Nürnberg for Renewable Energy (IEK-11), Egerlandstr. 3, 91058 Erlangen, Germany;Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia;Institute of Technology, University of Tartu, Nooruse 1, 50411 Tartu, Estonia;

关键词: choline;    eutectic mixture;    differential scanning calorimetry;    ionic liquid;    phase diagram;   

DOI  :  10.3390/molecules25071691

来源: DOAJ

【 摘 要 】

Mixing ionic liquids is a suitable strategy to tailor properties, e.g., to reduce melting points. The present study aims to widen the application range of low-toxic choline-based ionic liquids by studying eight binary phase diagrams of six different choline carboxylates. Five of them show eutectic points with melting points dropping by 13 to 45 °C. The eutectic mixtures of choline acetate and choline 2-methylbutarate were found to melt at 45 °C, which represents a remarkable melting point depression compared to the pure compounds with melting points of 81 (choline acetate) and 90 °C (choline 2-methylbutarate), respectively. Besides melting points, the thermal stabilities of the choline salt mixtures were investigated to define the thermal operation range for potential practical applications of these mixtures. Typical decomposition temperatures were found between 165 and 207 °C, with choline lactate exhibiting the highest thermal stability.

【 授权许可】

Unknown