Keratin-Based Biocomposites Reinforced and Cross-Linked with Dual-Functional Cellulose Nanocrystals

Abstract

Green composites from naturally derived polymers have gained more and more research interests recently due to their sustainable and environmentally friendly nature. In this work, biocomposite films based on keratin reinforced by surface-functionalized cellulose nanocrystals are prepared for the first time. Dialdehyde groups were successfully introduced onto the surface of cellulose nanocrystals with their reinforcing and cross-linking effects on the properties of keratin biocomposites systematically studied. Ouali and Halpin–Kardos models were applied to elucidate reinforcing mechanism of the nanofillers. The functionalized nanofillers which could improve interfacial interactions facilitated not only formation of percolating nanofiller network in keratin matrix but also effective interfacial stress transfer, leading to significantly improved mechanical properties of the biocomposites. This reinforcing as well as cross-linking strategy by functionalized cellulose nanocrystals could enrich the exploration of high-performance composites and extend exploration of the applications of keratin materials in the fields of tissue engineering or drug delivery.