A two-step strategy promotes the dissolution of corn stover-based lignocellulosic biomass in DBU/CO2/DMSO solvent system.

The dissolution and homogeneous processing of lignocellulosic biomass presents a significant challenge for advanced biorefineries. In this work, we firstly investigated the dissolution behavior of corn stover-based lignocellulose in 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU)/CO2/DMSO solvent system. The dissolution proportion reached 74.3 % via a two-step procedure, which involved pretreating of corn stover in DBU/DMSO solvent at 140 °C for 4 h, followed by dissolution at 50 °C for 6 h under 5 MPa CO2. Furthermore, the solubility of the corn stover can be improved by ball-milling treatment. Rheological behavior revealed that the solution viscosity and the intermolecular interactions decreased following ball-milling treatment. Subsequently, a small amount of wood pulp cellulose was incorporated to produce mechanically robust, fully UV-shielding, and all-biomass composite films. The tensile strength of the composite film containing 50 wt% wood pulp cellulose reached 47 MPa. This study provides significant insights into the development of green dissolution systems for lignocellulose and the development of lignocellulose-based advanced materials.