Synthesis and Characterization of Poly(Lactic Acid) (PLA)/Chitosan/Microcrystalline Cellulose (MCC) Composite Filament

Abstract

This study develops an industrially applicable composite by combining polylactic acid (PLA) with chitosan (CS) for antimicrobial properties and microcrystalline cellulose (MCC) for enhanced mechanical performance. Mechanical behaviour, microstructure, and morphology were analysed using tensile tests, scanning electron microscopy (SEM), and X‐ray diffraction (XRD). Antibacterial activity was evaluated against Gram‐positive and Gram‐negative bacteria. The samples were prepared by heating thermoplastic polylactic acid (PLA) and subsequently molding them into test specimens in accordance with ASTM D638. Results showed that adding MCC increased tensile strength and modulus, with the highest values in PLA (A) containing 2% MCC and 2% CS. Higher MCC content caused agglomeration, reducing mechanical properties. SEM and XRD revealed that MCC increased crystallinity, while CS decreased it. PLA/MCC/CS composites demonstrated stronger antibacterial activity than pure PLA. The findings indicate that the composites offer both improved mechanical properties and enhanced antibacterial function, making them promising for biomedical applications. Further optimization is needed to improve interfacial adhesion and reinforcement dispersion.