Preparation and characterization of cellulose nanofibrils via surface xanthation.

The growing demand for sustainable materials has driven the development of efficient, energy-saving methods for scalable nanocellulose production. This study presents the synthesis of xanthate-modified cellulose nanofibrils (XCNF) through a xanthate esterification process. Key parameters such as alkali concentration, carbon disulfide (CS2) dosage, and reaction time were optimized to evaluate their effect on the degree of substitution (DS). After xanthate groups were introduced under mild condition, low-energy mechanical fibrillation produced XCNF with high aspect ratios (up to 500) and stable dispersibility. XCNF films were prepared by vacuum filtration of the XCNF suspension, showing significantly improved mechanical properties, particularly higher toughness, while maintaining tensile strength. The XCNF film achieved a tensile strength of 32 MPa while maintaining excellent toughness (320 kJ·m-3) and modulus (1800 MPa). In conclusion, the xanthate esterification method provides a sustainable, cost-effective approach to nanocellulose production, bridging small-scale research and large-scale manufacturing. This study lays a foundation for advancing cellulose-based materials in applications such as nanopaper.