Sustainable and High Performing Biocomposites with Chitosan/Sepiolite Layer-by-Layer Nanoengineered Interphases

Biocomposites encompassing biopolymers and natural fibers represent potential candidates for the replacement of fossil-based polymers in many application fields. However, due to poor matrix/fiber interphase produces insufficient mechanical properties for practical application. In this Letter, we use the Layer-by-Layer assembly technique in order to modify the surface of natural fibers and produce a nanostructured interphase capable of improving the mechanical properties of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)/hemp fibers biocomposites. Chitosan and sepiolite nanorods have been selected as interphase constituents. When assembled on hemp fibers, this chitosan/sepiolite system conformally coats every fiber yielding a nanostructured coating that subsequently becomes the matrix/fiber interphase during composite preparation. Thanks to the LbL assembled interphase, the biocomposites achieve impressive mechanical properties with elastic moduli up to 2.6 GPa, which is 70% and 30% better of the neat matrix...