Chlorine-free alternatives to the synthesis of ionic liquids for biomass processing

Gurau, Gabriela; Wang, Hui; Qiao, Yun; Lu, Xingmei; Zhang, Suojiang; Rogers, Robin D.

doi:10.1351/PAC-CON-11-11-10

Pure Appl. Chem., 2012, Vol. 84, No. 3, pp. 745-754

http://dx.doi.org/10.1351/PAC-CON-11-11-10

Published online 2012-02-10

Chlorine-free alternatives to the synthesis of ionic liquids for biomass processing*

Gabriela Gurau¹, Hui Wang¹, Yun Qiao², Xingmei Lu², Suojiang Zhang² and Robin D. Rogers^1,2*

¹ Department of Chemistry and Center for Green Manufacturing, The University of Alabama, Tuscaloosa, AL 35487, USA
² Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China

Abstract: Ionic liquids (ILs) are desirable for use in a large number of applications because of their unique properties; however, compositions comprising only a single IL are expensive to synthesize and difficult to purify, and the widely used chloride-based ILs can be toxic and corrosive. Therefore, there is a need for new IL compositions that minimize common disadvantages encountered with single IL composition and synthetic methods which avoid halide intermediates. In this study, IL mixtures, which are chloride-free, were synthesized by a one-pot process, and the mixtures were used to dissolve biopolymers. The synthesized IL mixtures show high capability to dissolve the two exemplary biopolymers, cellulose and chitin.

*Pure Appl. Chem. 84, 411–860 (2012). A collection of invited papers for the IUPAC project 2008-016-1-300 “Chlorine-free Synthesis for Green Chemistry”.