Investigation of Mechanical and Thermal Properties of Modified Silica Aerogels/Epoxy/Aramid Composites

Due to its high pore size and low density, amine-modified silica aerogel (XSA) is an excellent candidate for the secondary reinforcement material of polymer matrix composites. In this study, the mechanical, thermal, and morphological properties of amine-modified silica aerogel-reinforced aramid/epoxy composite (EAFS) produced by the hand lay-up method were investigated. According to the resin weight, 1 wt.% (EAFS-1), 2 wt.% (EAFS-2), and 3 wt.% (EAFS-3) XSA reinforcements were dispersed into the epoxy resin by ultrasonic mixer. Tensile, three-point bending, compression, and shear tests were performed to determine the mechanical properties, while thermal properties were determined by dynamic mechanical analysis and thermogravimetric analysis. The mechanical properties demonstrated an upward trend up to EAFS-2, after which a decline was observed at EAFS-3. Tensile strength, modulus of elasticity, flexural strength, flexural modulus, and compressive strength of EAFS-2 increased by 20.43%, 30.91%, 10.09%, 24.01%, and 3.62%, respectively, compared to EAFS-0. Furthermore, the incorporation of XSA reinforcement resulted in a delay in the onset and endset of the degradation temperature.