Mechanical Properties of Polylactic Acid Nanofiber Films Reinforced by Modified Cellulose Nanocrystals

In this study, the surface of cellulose nanocrystals was first modified with citric acid, and the resultant modified cellulose nanocrystals (MCNC) were subsequently utilized as a reinforcement phase for polylactic acid (PLA). Findings indicated that MCNC interacted with PLA through hydrogen bonding, resulting in improved thermal stability, mechanical properties, and surface hydrophobicity of PLA nanofiber films. Specifically, the thermal degradation temperature, tensile strength, elongation at break, and contact angle of the nanofiber films increased by 19°C, 30.04%, 49.11%, and 11.22°, respectively, with a 3% addition of MCNC. Subsequently, utilizing PLA/MCNC as the base material and kaempferol as the active ingredient, a preliminary exploration into its potential as an active packaging material was carried out. When the addition amount of kaempferol was 10%, the DPPH and ABTS free radical scavenging ability of the nanofiber film reached more than 90%, demonstrating its application potential as an active packaging material. These results offer a promising strategy for the effective dispersion of CNC within PLA matrices, thereby expanding the potential applications of PLA in the field of active packaging.