Interfacial engineering of bacterial cellulose composites with enhanced mechanical robustness and environmental stability via itaconic acid–based poly(urethane-amide)

초록

Bacterial cellulose (BC) is a promising sustainable polysaccharide material owing to its hierarchical nanofibrillar structure and high crystallinity; however, its inherent brittleness and moisture sensitivity limit its practical applications in flexible structural materials. Herein, an interfacial engineering strategy is developed to enhance the structure–property relationships of BC by impregnating its porous network with an itaconic acid (IA)–based bio-poly(urethane-amide) (PUA). The enhanced performance is attributed to conjugation-mediated electronic modulation, which strengthens interfacial noncovalent interactions between the elastomeric matrix and cellulose nanofibers, thereby improving load transfer efficiency within the composite. As a result, the composite exhibits a nearly 100-fold increase in elongation at break and an approximately 15-fold improvement in toughness compared to pristine BC. In addition, the material demonstrates a modulus of ~272 MPa at 2% strain and a tensile strength of 9.7 MPa, comparable to conventional synthetic leathers. The composite also shows excellent elastic recovery with negligible permanent deformation and a crease recovery of 86.1%, along with stable mechanical performance under exposure to water, ultraviolet irradiation, and representative solvents. These results demonstrate that interfacial engineering of bio-based polymers provides an effective and scalable route to design mechanically robust BC composites for sustainability-oriented structural material applications.

키워드