Preparation of Hydrophobic Cellulose Composites via Carbonation and Their Application in PLA-Based Biocomposites

Poly(lactic acid) (PLA) is a biodegradable polymer with notable environmental benefits; however, its inherent brittleness limits its broader application.Microfibrillated cellulose (MFC) has been widely investigated as a reinforcing filler owing to its high strength and stiffness; however, the poor interfacial compatibility between hydrophilic MFC and hydrophobic PLA typically leads to filler agglomeration and inefficient stress transfer.Herein, MFC was modified using in situ-synthesized CaCO 3 followed by fatty-acid treatment to improve its compatibility with PLA.The resulting MFC-CaCO 3 composite filler was incorporated into PLA, and its influence on the mechanical and thermal properties of the resulting composites was evaluated.The incorporation of MFC-CaCO 3 markedly enhanced the tensile properties of PLA compared with those of pristine PLA and PLA-MFC composites.Fracture surface analysis revealed more uniform filler dispersion and stronger interfacial adhesion, indicating more effective stress transfer between the composite filler and the PLA matrix.Thermogravimetric analysis showed a slight reduction in thermal stability, which was attributed to alkaline