Thermal and Mechanical Characterization of an Aeronautical Graded Epoxy Resin Loaded with Hybrid Nanoparticles

Synthesized silica nanoparticles (SiO2) were coated with a thin polydopamine (PDA)shell by a modified one-step procedure leading to PDA coated silica nanoparticles (SiO2@PDA).Core-shell (CSNPs) characterization revealed 15 nm thickness of PDA shell surrounding the SiO2 core(~270 nm in diameter). Dierent weight percentages of CSNPs were employed as filler to enhancethe final properties of an aeronautical epoxy resin (RTM6) commonly used as matrix to manufacturestructural composites. RTM6/SiO2@PDA nanocomposites were experimentally characterized in termsof thermal stability and mechanical performances to assess the induced eects by the synthesizedCSNPs on pristine matrix. Thermal stability was investigated by thermogravimetry and data weremodelled by the Doyle model and Kissinger methods. An overall enhancement in thermal stabilitywas achieved and clearly highlighted by modelling results. Dynamic Mechanical Analysis hasrevealed an improvement in the nanocomposite performances compared to the neat matrix, with anincrease in the glassy (+9.5%) and rubbery moduli (+32%) as well as glass transition temperature(+10 C). Fracture Toughness tests confirmed the positive eect in damage resistance compared tounloaded resin with an impressive variation in critical stress intensity factor (KIC) and critical strainenergy (GIC) of about 60% and 138%, respectively, with the highest SiO2@PDA content.