Biomimetic polypropylene-carbon intra-ply hybrid 3D woven composite with enhanced impact resistance

In this study, a nacre-inspired carbon-polypropylene 3D woven composite is developed. The biomimetic ‘brick-and-mortar’ design is implemented by interlacing softer polypropylene yarns with brittle carbon fibres. This novel composite was benchmarked against a standard carbon fibre 3D woven composite with identical weave architecture, examining tensile properties, impact resistance, and shear strength. The comparative analysis was supported by micrographs and μ CT scans. Results showed that the hybrid composite absorbed 16% more impact energy in the weft direction than its purely carbon counterpart. The presence of polypropylene yarns increased crimp within the weave contributing to reduced tensile and shear properties. The study identifies the bulk factor of polypropylene yarns as critical in minimising crimp and structural flaws in the hybrid design. In summary, this work presents a nature-inspired hybrid composite, with an increased impact resistance but with trade-offs in tensile and shear properties. • Polypropylene and carbon fibre yarns were woven in a 3D composite inspired by nacre. • The Charpy impact strength (energy per unit volume) was 16% higher for the novel material. • There was a reduction in tensile and shear properties.