Design of high impact-resistant PBO fiber/epoxy vitrimer composites: Multi-scale energy dissipation strategy

The development of lightweight and high-performance fiber-reinforced composite protective equipment holds great significance for national defense and personal safety. Composite materials necessitate a matrix resin exhibiting both strength and toughness, while the design and application remains significant challenge. Herein, a new composite material with multi-scale energy dissipation structure is designed based on the failure mechanism of composite materials under impact, the impact resistance of the obtained material (129.2MJ·m −3 ) is significantly improved by 34 % compared with traditional composite material (96.5 MJ·m −3 ). The incorporation of epoxy vitrimer with dynamic non-covalent bonds imparts an impact-stiffening effect to the originally brittle matrix, thereby meeting higher requirements for impact resistance. The addition of carbon nanotubes in the epoxy vitrimer matrix improves its strength and toughness. The reinforcement consists of high-performance PBO fiber that is surface treated with oxygen plasma. The composite material exhibits excellent interface bonding, which directly contributes to the improvement of interlaminar shear strength from 7.84 MPa to 11.56 MPa. This composite material structure design based on multi-scale energy dissipation mechanism confirms the possibility of further lightweight and high-performance bulletproof composite materials.