Investigating the effect of silica aerogel content on the mechanical properties of epoxy resin system

Nowadays, silica aerogels have been widely used in many applications due to their extremely low density, low thermal conductivity and high specific surface area. Many researchers have proved that the addition of the nanoparticles into thermoset polymers resin has influenced the mechanical properties of the composites. Epoxy resins are one of the mostly used thermoset polymers. Although they have superior mechanical strength, they are usually suffered from their fragile structure. There are several additives such as carbon nanotubes, nanoclay, calcite etc. that can be added to epoxy resins to enhance their mechanical properties such as tensile strength, modulus of elasticity, break strain. In this study, the silica aerogels were added as nano-fillers into epoxy to investigate the effect of the silica aerogel content on the mechanical performance of silica aerogel–epoxy composites. Two different silica aerogel–epoxy composites were produced with various silica aerogel content (0.5 and 1 wt. %) and effect of aerogel amount on the mechanical and structural properties of final nanocomposites was investigated. Silica aerogels used in the study were synthesized by traditional sol gel method to obtain versatile silica aerogel–epoxy composites. Apart from the classically synthesized silica aerogels, aerogels in the present study contain short chained ionic liquid (IL) as porogenic agents. The effect of the addition of the silica aerogel on the tensile and flexural properties of final composites were observed by the measurement of the tension and three-point bending tests, respectively according to ASTM standard. The results have shown that the mechanical behavior of the epoxy resin was significantly influenced by the silica aerogel addition. The mechanical strength of epoxy composite with silica aerogel addition was improved compared to that of the neat epoxy.