AUTHOR=Hong Si , Shen Xiao-Jun , Sun Zhuohua , Yuan Tong-Qi TITLE=Insights into Structural Transformations of Lignin Toward High Reactivity During Choline Chloride/Formic Acid Deep Eutectic Solvents Pretreatment JOURNAL=Frontiers in Energy Research VOLUME=8 YEAR=2020 URL=https://www.frontiersin.org/journals/energy-research/articles/10.3389/fenrg.2020.573198 DOI=10.3389/fenrg.2020.573198 ISSN=2296-598X ABSTRACT=
Understanding lignin structural transformations during DES pretreatment would facilitate to produce lignin with tailor-made properties based on intended applications. To unravel the structural variant of lignin in the DES, the alkali lignin (AL) was pretreated in choline chloride/formic acid (ChCl/FA) (the ratio of 1:2) at 80–120 °C. Characterization of the AL and regenerated lignin samples were determined to understand lignin structure, such as linkage in lignin, phenolic OH content, molecular weight, and aromatic products. ChCl/FA DES pretreatment resulted in large amounts of the dissociation of β-