Dissolution behavior and molecular dynamics study of cellulose in quaternary ammonium hydroxide/ethylenediamine solvent system

In this paper, a new green solvent system \(\text{TEAH/EDA/H}_{2}\) O is used to study the dissolution behavior of microcrystalline cellulose. Through FT-IR, XRD, TG, DSC and other characterization methods and molecular dynamics simulation experiments, the results show that this solvent system has excellent solubility for cellulose at low concentrations. When the concentration of the solvent system is 18.75 wt% at room temperature, its solubility for cellulose can reach 13.79 wt%, which greatly improves the solubility of cellulose, and the solubility region is increased. It is also found that EDA increased the solubility of cellulose in the solvent by destroying the crystal structure of cellulose in the early stage of the dissolution process. Molecular dynamics (MD) simulation studies have shown that EDA quickly changes the crystal structure and destroys the interchain hydrogen bonds, and forms an elliptical columnar inclusion complex with \(\text{OH}^{-}\) , \(\text{H}_{2}\) O, \(\text{TEA}^{+}\) and cellulose chains to regulate the hydrophilicity of cellulose, thereby achieving efficient dissolution of cellulose in \(\text{TEAH/EDA/H}_{2}\) O solvents.