Improving the Flexural Properties of E-Glass Fibers/Epoxy Isogrid Stiffened Composites through Addition of 3-Glycidoxypropyltrimethoxysilane Functionalized Nanoclay

This research work investigates the effect of silane functionalized nanoclay on the flexural response of E-glass/epoxy isogrid stiffened composite (IGSC). To do so, the sodium montmorillonite nanoclay were functionalized by 3glycidoxypropyltrimethoxysilane as a silane coupling agent. In the following, by using the mechanical stirrer and ultrasonic waves, the surface functionalized nanoclay particles with the different weight percentages (0, 1, 3, and 5 wt.%) were dispersed into the epoxy resin. After that, the IGSC panels containing the functionalized nanoclay were made by combining the filament winding and hand lay-up methods. By using the Fourier transform infrared (FT-IR) analysis, the functionalizing trend of nanoclay particles was characterized. It was realized that by adding 5 wt.% functionalized nanoclay to IGSC, the flexural load, flexural stiffness and energy absorption of that were reached to 1402 MPa, 82.6 N/mm and 233.9 J/kg, respectively, which were the maximum improvement of those properties. By using electron microscopy examinations from the fracture surfaces of IGSC structures, it was found that the presence of silane functionalized nanoclay particles improved the interfacial adhesion between the epoxy matrix and E-glass fibers.