Fiber‐reinforced sustainable biomimetic Bouligand structures for hot and humid environments

Abstract The mechanical properties of existing materials can be improved with the Bouligand structure. However, most current studies mainly focus on improving material properties with Bouligand structure in ambient temperature environments and neglect the weakening of the properties in hot and humid environments. Thus, we chose bamboo, which is highly hydrophilic with a natural unidirectional structure, as the raw material to prepare bamboo composite laminates with the Bouligand structure. The effect of humid and hot environments on the mechanical properties of laminated materials with the Bouligand structure was investigated. The results showed that the Bouligand structure was greatly affected by the humid–hot environment, and the smaller the laying angle of the spiral, the lesser the effect of the humid–hot environment on the mechanical properties. Additionally, in the hot and humid environment, the bending strength and impact strength of the laminated materials decreased by 11.45% and 11.57%, respectively, at a layup angle of 10° compared with those at room temperature, indicating that the spiral layup angle greatly impacted the mechanical properties in hot and humid environments. This study provides insight into the application of the Bouligand structure in improving material properties in hot and humid environments. Highlights Exploring the performance changes in the bionic Bouligand structure in hot and humid environments. Exploring the optimal angular mechanical properties of the Bouligand structure by changing the helical layup angle in both wet and dry environments. Developing a novel green biomass material with a biomimetic Bouligand structure using the unique natural unidirectional structure of bamboo, expanding the application fields of biomaterials.