Fabrication, Characterization, and Antimicrobial Activity of PLA/Chitosan Composites Reinforced With Sugarcane Bagasse–Derived Fillers

ABSTRACT

This study developed polylactic acid (PLA) composites reinforced with chitosan (CS) and sugarcane bagasse‐derived fillers, including untreated sugarcane bagasse (SCB), ultrasound‐assisted‐alkaline‐treated sugarcane bagasse (UASCB), and ultrasound‐assisted‐alkaline‐acid‐treated (UAASCB). The objective was to improve the structural and functional properties of PLA composites through fiber treatment and chitosan incorporation. Fiber treatments significantly increased the cellulose content and crystallinity of SCB, with the best result reaching 71.7% cellulose and 91.36% crystallinity after 30 min of 4 wt% NaOH treatment followed by 45 min of 2 N sulfuric acid treatment. Composite characterization was carried out using FTIR, XRD, SEM, and tensile testing. In this study, pure PLA showed a tensile strength of MPa and a tensile modulus of MPa. The PLA–CS–UASCB composite showed a comparable tensile strength () MPa with a slight increase in tensile modulus () MPa. In contrast, the PLA–CS–UAASCB composite displayed lower tensile strength () MPa and tensile modulus () MPa. The PLA–CS–UASCB composite demonstrated the highest antimicrobial activity, reducing the growth of E. coli by 20.28% and S. aureus by 28.33%. This research offers a promising foundation for further development of sustainable PLA‐based biocomposites tailored for multifunctional and environmentally friendly applications.