(240b) Impact of Methoxy Group Component of Lignin-Derived Deep Eutectic Solvents on the Biomass Pretreatment Performance

Deep eutectic solvents (DESs) can be readily synthesized with relatively low costs compared to ionic liquids (ILs). We have investigated lignin-derived DESs as a green technology for biodegradability and biocompatibility along with the valorization of lignin. The chemical structure of hydrogen bonding donor (HBD) and hydrogen bonding acceptor (HBA) are crucial to determine the performance of DESs. In this study, lignin-derived HBDs which are methoxy-substituted phenol structures were applied to synthesize DESs, and hydrogen bonding formation and physical and thermal properties of DESs were studied. In addition, the impacts of HBD structure on each DES performance with biomass conversion were investigated. DESs including phenol, guaiacol, and syringol as a model compound were evaluated by differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), rheometer, and nuclear magnetic resonance (NMR). The performances of DESs on sugar maple were evaluated by the chemical compositions and sugar conversion of cellulose-rich fraction after DESs pretreatment. The recovered lignin was characterized with the GPC and 2D HSQC.