Compósitos de estruturas sanduíche de fibra de carbono e honeycomb em matriz epóxi aditivada com nanolâminas de grafite expandida.

Abstract

In the present work there was the development of a structural sandwich panel with bidirectional 3k carbon fiber faces, PN1 aramid fiber honeycomb core of regular geometry and as adhesive material is used epoxy resin of the modified HEX 135 system. Such modification was carried out by adding expanded graphite nanosheets (EGN). The Top-down method was used to obtain expanded graphite with chemical treatment from natural graphite in flakes, using sulfuric and nitric acids, respectively, with a dosage of 4:1v/v for graphite exfoliation, being filtered, expanded at 800ºC followed by an ultrasound bath process to generate the expanded graphite nanosheets. Its characterization was analyzed by the methods of Infrared Spectroscopy (FTIR), Raman Spectroscopy, X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive XRay Spectroscopy (EDS). The fabrication of the structural panels was done by hand lay and vacuum bag lamination. The addition of nanoparticles in the adhesive material has an initial dose of 0.5%, varying in an increasing way until reaching 1%, also making samples with pure epoxy resin for comparison (0%, 0.5% and 1%) through the in situ method. In order to characterize the pure epoxy resin and additivated with nanoreinforcement, FTIR, Raman, XRD, SEM, EDS analyzes were carried out and, to evaluate the mechanical performance of the composite specimens, mechanical tensile and bending tests were performed, which were later verified with ANOVA analysis and Tukey test. The results of the process of obtaining the EGN are satisfactory. The characterizations referring to the method to add to the epoxy resin point to efficiency and higher carbon concentration in the additivated samples, although low. As for the mechanical tests, it indicates a reduction in the performance of the mechanical properties of bending and traction, respectively.