High-performance biodegradable polylactide films with nano-reinforced stereo-complex polylactide and layered crystalline structures for eco-friendly packaging applications.

The development of high-performance biodegradable polylactide (PLA) packaging materials with enhanced barrier properties and transparency is essential for sustainable food packaging applications. In this study, a layer-by-layer self-assembly approach was employed to construct layered crystalline structures and induce the formation of nano-reinforced stereo-complex polylactide (sc-PLA), leading to the successful fabrication of high-performance biodegradable PLA films. The continuous sc-PLA crystal layers functioned as nanostructured barriers, extending the diffusion path of gas molecules and significantly enhancing the barrier properties. Specifically, this research achieved a precisely optimized oxygen transmission rate (OTR) of 1.55 ± 0.17 cc·mil/(m·day·atm), the water vapor transmission (WVT) of 47.71 ± 5.69 g/(m·day), the nanoscale crystals improved visible light transmittance, resulting in a film transparency of 92.45 %. These results demonstrate that the biodegradable PLA barrier films exhibit exceptional overall performance. Importantly, the synergistic effect between the layered crystalline structures and the nano-reinforced sc-PLA crystals formed an efficient "nano-barrier wall" effectively addressing the inherent limitations of biodegradable PLA films. This study provides a novel strategy for designing high-performance biodegradable PLA films with self-reinforced sc-PLA and layered crystalline structures, advancing the development of eco-friendly packaging materials.