Fabrication and characterization of the carbon nanotube and SiO2 nano particle reinforced three dimensional glass fiber-epoxy composite

In this study, nano particle reinforced 3 dimensional (3D) glass fiber/epoxy composite manufactured, mechanical, thermal and micro structural specifications were investigated. The 3D composites were reinforced at 0.3 wt.%; 0.5 wt.%; 1 wt.%; 2 wt.% ratios with multi walled carbon nano tube (MWCNT) and at 0.5 wt.%; 1 wt.%; 2 wt.%; 3 wt.% ratios with nano SiO2. 3D composites were manufactured with the hand lay-up method and vacuum infusion method and have been examined for the resin absorption, bubble formation, weight and dimensional stability specifications in order to find the best method. It is understood that the vacuum infusion method has proven to be the most efficient method with the most homogeneous resin absorption, lowest bubble formation and better dimensional stability results. 3D composites were produced both in the weaving direction (warp) and the perpendicular to weaving direction (weft). The hardness measurement, three-point bending, low-speed impact and tensile tests were performed to examine the mechanical properties of the nano particle reinforced 3D composites. The applied scanned electron microscopy (SEM) and energy dispersive spectroscopy (EDS) to the cracked surfaces, the fracture mechanism and nano particle dispersion were investigated. The effect of the nano particle reinforced on the 3D composites thermal properties researched with the differential scanning calorimeter DSC, thermal gravimeter and dynamic mechanical analysis. According to the mechanical test results, the addition of the MWCNT and nano SiO2 particles to the 3D glass fiber/epoxy composite increased the bending strength, tensile strength and impact strength of the composite. The obtained increase was detected in both warp and weft directions. The highest bending and tensile strength were obtained at 1 wt.% MWCNT and at 1 wt.% nano SiO2 ratios, the highest impact results obtained at 0.5 wt.% MWCNT and at 2 wt.% nano SiO2 ratios. According to the SEM and EDS analysis the MWCNT and nano SiO2 particles homogenously dispersed by the used ultrasonic mixing method. The damage seen in 3D composites between lower battery and the surface mesh connection as the matrix cracks and then revealed that develops as the breaking of the composite. According to the results of the thermal analysis, the MWCNT and nano SiO2 particle reinforcement of the 3D composites increase the glass transition and thermal decomposition startup temperature. Accordingly, the addition of the nano particles to the 3D composite was found to extend the operating temperature range of the material. It has been detected in DMA studies the elasticity of the particle reinforced 3D composites were improved. The same results were obtained by the mechanical test. The composites that giving higher tanδ value at the reference temperature proved that could withstand higher temperatures without losing the properties. All detailed manufacturing studies, wide range test and analysis carried out under the thesis work revealed that the addition of the MWCNT and nano SiO2 particle to the 3D glass fiber/epoxy composites improve the mechanical, thermal and microstructure properties. At the end of studies the reference material acquired superior properties and has been turned into a more qualified new composite product.