Transformation of Crystalline Cellulose IIII to Cellulose Iβ in Semi-Flow Hot-Compressed Water Treatment

Abstract

Crystalline cellulose I (a mixture of Iα and Iβ) from cotton linter (Gossypium hirstum L.) was converted into cellulose IIII by ethylenediamine treatment. However, the crystalline cellulose IIII was found to be transformed into cellulose Iβ after semi-flow hot-compressed water (HCW) treatment at a range of temperatures between 20–270°C under 4–10 MPa for 15 min. This transformation, from cellulose IIII to Iβ, was studied by X-ray diffraction (XRD) method. The analysis by the XRD method revealed that the transformation occurred at temperature below 200°C. The XRD peaks showed that the 002 lattice diffraction angles for treated crystalline cellulose IIII were shifted to around 22.5° from about 20.8°. These results confirmed that the conversion process was occurred in the semi-flow HCW system.