Chemical characteristics of heterogeneous lignocellulosic microfines prepared using the glycol ether-organosolv process: dissolution properties in an NaOH–urea aqueous solution

Abstract

Abstract In this study, heterogeneous lignocellulosic microfines (LCMFs) with different physicochemical properties were prepared from softwood by adjusting the reaction conditions of a glycol ether-organosolv process. The dissolution properties of heterogeneous LCMFs in an NaOH–urea aqueous solution were evaluated. As the reaction time increased, the yield and residual lignin content decreased. As the amount of chemical solution used to prepare LCMFs increased, more lignin than carbohydrates were removed, but the degree of polymerization (DP) was maintained. Finally, LCMFs with different residual lignin content, DP, and crystallinity were prepared via the glycol ether-organosolv process under various conditions. It was observed that lower the lignin content of heterogeneous LCMFs, higher were their solubilities in the NaOH–urea solution. The effect of DP on solubility was not significant; however, the hemicellulose content of LCMFs had a greater effect on their solubilities in the NaOH–urea aqueous solution than the sugar composition of hemicellulose. The chemical properties of lignin present in LCMFs had no significant effect on their solubilities in the NaOH–urea aqueous solution.