Novel epoxy/cyclic olefin copolymer/carbon structural composites with electro‐activated self‐healing properties

Abstract

Multifunctional self‐healing composites have great potential in several applications, i.e., from automotive to aerospace. This study examines the self‐healing behavior of carbon fiber reinforced composites by depositing jet‐spun cyclic olefin copolymer (COC) meshes on dry carbon fiber plies before lamination with epoxy resin (EP). Three different laminates were prepared, including neat EP/CF and two composites with 4 wt.% and 8 wt.% of COC in the form of a jet‐spun network as a healing agent. The introduction of COC mesh reduced flexural stress by 26% and interlaminar shear strength by 50%. Mode I interlaminar fracture toughness (GI) was evaluated and specimens were mended at 110°C by resistive heating generated by an electrical current flowing within the samples. The laminates containing 8 wt% COC reported a healing efficiency, evaluated as the ratio between the GI and as the ratio of the maximum load (PMAX) of virgin and healed samples, of 9.4% and 33.7%, respectively. Fractography analysis highlighted the poor adhesion between the COC mesh and EP matrix, and several COC microfibers were trapped inside the epoxy matrix, hindering their diffusion inside the crack zone, which limited the healing capability of the prepared laminates.

Effect of particle size distribution on the cryogenic mechanical properties of triple‐base propellants

“…[1][2][3] The enhancement of material performance is one of the main goals of particle composites. [4][5][6] By choosing the right particle and matrix combinations, specific performance improvements can be made, such as enhanced strength, 7 thermal conductivity, 8 electrical conductivity, 9 wear resistance, [10][11][12][13] and more. The performance of materials at the macroscopic level is entirely different from the performance of the elements 14 ; it is not merely the sum or average of the specific qualities of various components inside the structure.…”

“…The composition of particle‐reinforced composite materials typically consists of a base matrix material into which additional particles are inserted to improve or alter the qualities of the material 1–3 . The enhancement of material performance is one of the main goals of particle composites 4–6 . By choosing the right particle and matrix combinations, specific performance improvements can be made, such as enhanced strength, 7 thermal conductivity, 8 electrical conductivity, 9 wear resistance, 10–13 and more.…”

Enhancing interfacial adhesion of carbon fiber/poly(phthalazinone ether ketone) composites by the hybrid sizing agent of hydroxyapatite‐reinforced PAEK‐COOH

“…Carbon fiber reinforced polymer (CFRP) has gained popularity because of its advantages, which include a rapid cycle of production, high toughness, outstanding thermal stability and fatigue resistance. CFRP is an adaptable material that has several applications in clinical, aerospace, military, building, and other fields 1–5 . The fascinating properties of CFRP, including its exceptional strength and high stiffness, low thermal expansion coefficient, and biological compatibility, account for its broad use 6–9 .…”