Mechanical and thermal characterization of laminar carbon/epoxy composites modified with magnesium oxide microparticles

Abstract

Abstract This paper investigates the effects of magnesium oxide (MgO) microparticles on the mechanical and thermal properties of laminated carbon fiber reinforced polymer composites. The polymer epoxy matrix was modified with 0% (pure), 2 wt%, and 4 wt% MgO fillers. Then the laminar composites were manufactured with the vacuum bag method. The energy absorption capacity and impact strength were determined from the Charpy impact tests, whereas the flexural characteristics were evaluated by conducting three‐point bending experiments. Scanned electron microscopy was used to examine both the dispersion of microparticles and the fracture surface of experimentally tested specimens. Thermal performance of the polymer composites with and without MgO additives was analyzed comparatively by performing the thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The decomposition temperatures and glass transition temperatures of the composites were obtained. Approximately 30% increment in impact strength was achieved thanks to the MgO fillers. However, although the flexural strength decreased since the MgO particles caused stress concentration, the flexural modulus was not affected due to the decrease of elongation at break. The TGA and DSC instrumentations showed that the decomposition temperatures increased, and curing behaviors were improved depending upon the MgO content.