Development and characterization of self-healing cellulose nanofiber reinforced polyurea composite materials based on multiple dynamic interactions

Abstract Inspired by the spontaneous healing of natural skin wounds, self-healing materials have become the focus of research. The repulsive conflict between mechanical and healing properties makes it challenging to optimize them simultaneously. Without sacrificing the healing properties, cellulose nanofiber (CNF)/polyurea (PU) composite materials with high mechanical strength were prepared using CNFs as filler and polyamine as cross-linking agent. To further improve the healing and repeated processing performance of the materials, dynamic disulfide bonds were also introduced into the CNF/PU composite materials. And the effects of disulfide bonds and cross-linking agents on the properties of CNF/PU composite materials were explored in detail. Among them, the tensile strength of CNF/PU-S-NH 2 is 14.51 MPa, the self-healing efficiency is 95.44%, and the tensile strength is 88.08% of the initial strength after four repeated processing. This research is of great significance for extending the service life of materials, slowing down the generation of waste materials, reducing environmental pollution, and making full use of renewable resources. Graphical abstract