Schiff base-grafted bacterial cellulose-PCL composites: Humidity/temperature-driven hydrogen bond reconfiguration for mechanically adaptive nanofiber

A novel graft copolymer BC-g-PCL was synthesized and characterized by integrating bacterial cellulose (BC) with polycaprolactone (PCL) to improve mechanical performance and sustainability. Molecular dynamics simulations reveal that hydrogen bonding is crucial for improving the strength and toughness of the material, with temperature fluctuations affecting the interactions of the polymer chains. The BC-g-PCL exhibits notable water plasticity and solvent responsiveness, enabling reversible transitions between dry and wet states due to the high surface wettability from exposed hydroxyl groups. Mechanical testing demonstrates that BC-g-PCL retains excellent ductility and strength across varying humidity conditions due to the dynamic formation of hydrogen bonds. Furthermore, recyclability and biodegradability assessments indicate substantial stability against organic solvents and successful regeneration via N , N -dimethylacetamide (DMAC)/lithium chloride (LiCl) dissolution, while maintaining robust mechanical properties even after multiple recycling cycles. These results make BC-g-PCL a promising eco-friendly alternative to traditional plastics, highlighting its potential for advanced functional materials and sustainable engineering applications derived from biological resources.