Enhancing the Mechanical Properties of Biodegradable Poly(lactic acid) Fibers through Melt Spinning with Cellulose Propionate from Rice Straw

In this study, propionate cellulose (CP) derived from rice straw was successfully prepared via propionic anhydride modification. Subsequently, a biodegradable fiber of poly(lactic acid) (PLA) physically modified by incorporating CP was obtained using the melt spinning method. The results demonstrated that the addition of 5 wt % CP significantly enhanced the tensile strength and elastic modulus of the propionate cellulose/polylactic acid-1 (CP/PLA-1) composite fiber to 150.9 MPa and 3.43 GPa, respectively, higher than pure PLA (67.7 MPa and 2.73 GPa). CP also had a dramatic effect on the drafting of composite fibers. The tensile strength and elastic modulus of CP/PLA-1 further improved to 423.5 MPa and 11.3 GPa, respectively, after the drawing process. In terms of degradation, the mass loss rates of PLA, CP/PLA-1, CP/PLA-2, and CP/PLA-3 remained below 3% after five months of natural degradation. Notably, a significant mass loss of 11.1% was observed in CP/PLA-4, which was only achievable when the CP content reached 20 wt %. This study sheds light on the promising mechanical and degradation properties of CP/PLA composite fibers, making them potential candidates for environmentally friendly applications.