Study on Bone-like Microstructure Design of Carbon Nanofibers/Polyurethane Composites with Excellent Impact Resistance

Abstract

It is a challenge to develop cost-effective strategy and design specific microstructures for fabricating polymer-based impact-resistance materials. Human shin bones require impact resistance and energy absorption mechanisms in the case of rapid movement. The shin bones are exciting biological materials that contain concentric circle structures called Haversian structures, which are made up of nanofibrils and collagen. The “soft and hard” structures are beneficial for dynamic impact resistance. Inspired by the excellent impact resistance of human shin bones, we prepared a sort of polyurethane elastomers (PUE) composites incorporated with rigid carbon nanofibers (CNFs) modified by elastic mussel adhesion proteins. CNFs and mussel adhesion proteins formed bone-like microstructures, where the rigid CNFs are served as the bone fibrils, and the flexible mussel adhesion proteins are regarded as collagen. The special structures, which are combined of hard and soft, have a positive dispersion and compatibility in PUE matrix, which can prevent cracks propagation by bridging effect or inducing the crack deflection. These PUE composites showed up to 112.26% higher impact absorbed energy and 198.43% greater dynamic impact strength when compared with the neat PUE. These findings have great implications for the design of composite parts for aerospace, army vehicles, and human protection.

Effects of process parameters on mechanical properties and interface of 3D printed bamboo‐inspired CCFR‐PLA/TPU composites

“…For instance, Meng et al 6 were inspired by the hierarchical structure in the hinge of Cristaria plicata, and designed soft and hard composite microstructures with deformability and fatigue resistance, providing insights into the development of fatigue‐resistant structural materials. Gao et al 7 successfully prepared carbon nanofiber‐reinforced polyurethane elastomers (PUE) composites with exceptional impact resistance by drawing inspiration from the tibia structure. These kinds of composites optimized by different materials are widely used in aerospace, automotive, and marine fields due to their excellent properties 8–11 .…”