Preparation And Characterization Of Interface Self-healing PBO Fibers Composites

Advanced resin matrix composite materials have excellent properties such as low density,high strength,high temperature resistance and impact resistance,but the interface structure of composite materials is easy to destroyed,resulting in different size micro-cracks,and the microcracks are difficult to detect and repair,which cause damage and failure of the composite.Self-healing materials based on photothermal conversion have the advantages of simple preparation,high repair efficiency and can fulfill multiple repairs in the same area,which have attracted wide attention of researchers.However,there are still few studies on self-healing of interfaces.PBO fiber is a high performance fiber and a commonly used reinforcing material.In this paper,the graphene oxide and metal organic framework with excellent light responsiveness are simultaneously introduced onto the surface of PBO fiber,and a modified layer with photothermal conversion function is formed on the surface of the fiber to realize the interface self-healing of PBO fiber monofilament composite material,while improving the UV resistance of PBO fiber.Graphene oxide and UIO-66 were synthesized by Hummers method and microwave method,respectively.After hydrothermal self-assembly,static adsorption and thermal contraction,rGO/UIO-66@PBO?PGU?fibers with coaxial structure were prepared.The results show that PGU fiber exhibits excellent self-healing properties as well as UV resistance with a slight decrease of mechanical properties.The modified fiber has a tensile strength of 4.32 GPa and a self-healing efficiency of 85.8%.After repairing the same area for 5 times,it can maintain a relatively stable repair efficiency of 85.3%.After UV irradiation for 288 h,the tensile strength retention of the monofilament of the PGU fiber was 73%.NH₂-MIL-88Fe is another metal-organic framework with excellent light responsiveness.Based on the above studies and the coordination of Fe³⁺with carboxyl groups and the electrostatic assembly of graphene oxide with NH₂-MIL-88Fe,in-situ growth and the dynamic adsorption methods are uplized to introduce a composite structure of GO/NH₂-MIL-88Fe on the surface of PBO fiber to prepare GO/NH₂-MIL-88Fe@PBO?PGF?fiber.The results show that PGF fiber also shows good self-repairing properties and UV resistance.The self-repairing efficiency is 81.33%,and the same area can still be repaired after 5 times self-healing maintain self-repair efficiency at 80%.The tensile strength retention of the monofilament of the PGF fiber was 56.1%after 288h ultraviolet light irradiation.