Abstract:

This study investigates the effect of reed powder particle size and morphology on the mechanical properties of polylactic acid （PLA） composites. The impact strength and flexural modulus were optimized at a particle size of 50 μm， achieving notched Izod impact strength of 3 kJ/m² at 23 °C and a flexural modulus of 3 690 MPa. Conversely， the 20 μm particles yielded the poorest performance. Furthermore， the use of a reed masterbatch （pre⁃compounded with white oil） was explored as a strategy to enhance processability. While the masterbatch effectively improved the melt flow rate of the composite， it resulted in a trade⁃off： impact performance increased compared to composites with directly added reed powder， but flexural strength decreased. The flexural modulus， however， exhibited a more pronounced increase. The investigation of masterbatch loading （10~30 wt%） demonstrated that increasing content led to higher density and flexural modulus， but reduced bending and tensile strength. Scanning electron microscopy of impact fracture surfaces indicated strong interfacial adhesion between the reed powder and the PLA matrix， confirming the potential of reed as a viable bio⁃filler for enhancing specific properties of PLA composites.

Key words: reed powder, polylactic acid, degradable, composite material