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Pre-impregnated carbon fiber/epoxy resin (CF/epoxy prepreg) gained its popularity for significant stress applications, especially in the aerospace industry, owing to its excellent resistance and low specific mass. However, these CF/epoxy prepregs have a tendency to crack propagation. A solution for the prepregs fragility is the addition of carbon nanotubes (CNTs), especially those functionalized with amino groups, reinforcing the material due to its exceptional mechanical properties. In this work, the influence of the carbon chain length of two different amino-functionalized CNTs from diverse backgrounds (commercial and laboratory growth CNTs) is studied. The nanofillers were added in CF/epoxy prepregs by dry spraying without solvent aid. CNTs' samples were characterized by X-ray photoelectron spectroscopy, Raman spectroscopy, transmission electron microscopy, and thermogravimetric analysis (TGA), while the composites were analyzed by TGA, dynamic-mechanical analysis, and field emission scanning electron microscopy. The various surface treatment occurred at different levels according to the CNTs background, and all samples exhibited a distinct behavior. These differences were also observed in the composites' thermomechanical performance: CNTs functionalized with larger carbon chain amine presented the best results, with an increase of almost 100% in the storage moduli (E'), confirming the efficiency of aminofunctionalized CNTs in the reinforcement of CF/epoxy prepregs.

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In order to contribute to the corrosion protection of aluminum alloys, silane-based hybrid coatings have been widely studied in the aerospace industry for their good adhesion to aluminum substrates, compatibility with organic paintings and to protect the underlying material, in addition to being much less toxic than the commonly used chromatization process. In this work, hybrid and inorganic sol-gel coatings were evaluated as corrosion inhibitor films for AA2024-T3 alloy. The films were characterized by linear polarization resistance (LPR) and scanning electron microscopy (SEM), which indicated that these coatings provide a lower tendency for the substrate corrosion.