![]() HBP strongly increase the fracture toughness and impact strength of the hosting matrix but, on the other hand, they can reduce the thermomechanical properties. ![]() Besides these reported benefits, inorganic nanoparticles can lead to a significant increase of the resin viscosity due to their high specific surface area, which inevitably will detrimentally affect the level processability of the hosting system in manufacturing composite materials and structures. have demonstrated that the addition of silica nanoparticles up to 10 wt% causes a remarkable enhancement in the fracture toughness and an increase in the critical crack length for the onset of crack propagation. Inorganic fillers are also widely employed as tougheners in the epoxy matrix Ragosta et al. ![]() have demonstrated an enhancement of the epoxy thermal stability with the incorporation of silica in particular, all the temperatures of degradation, i.e., Td 10 (10% weight loss), Td 50 (50% weight loss), and T max (maximum weight loss), have increased with the growth in silica domains of the hybrid epoxy–silica polymer. by adding 10% by weight of sepiolite, and, therefore, a remarkable improvement of the hosting epoxy matrix fire behavior and thermal stability was achieved. A significant reduction of the PHRR (Peak of Heat Release Rate) was observed by Zotti et al. ![]() reported the increase of thermal stability and the reduction of the mass loss rate by the addition of fumed silica to an epoxy matrix. In particular, silica and inorganic clays (e.g., montmorillonite and sepiolite ) are the most used inorganic fillers to improve the thermal and mechanical properties of epoxy resins. Inorganic fillers are generally used in thermosetting resins in order to reduce the coefficient of the thermal expansion of finished products and to increase the thermal stability of the composite system. Finally, fracture toughness analysis revealed that both the critical stress intensity factor (K IC) and critical strain energy release rate (G IC) increased with the CSNPs content, reporting an increase of about 32% and 74%, respectively, for the higher filler loading. The Kissinger Method was employed in order to study the thermal stability of the nanocomposites the degradation activation energies that resulted were higher for the sample loaded with low filler content with a maximum increase of both degradation step energies of about ~77% and ~20%, respectively. Although the incorporation of 2.5 wt% of CSNPs induces a ~4 ☌ reduction of the hosting matrix glass transition temperature, a slight increase of the storage modulus of about ~10% was also measured. An aeronautical epoxy resin was loaded with the synthesized CSNPs at different percentages and thermal properties, such as thermal stability and dynamic mechanical properties, were investigated with the use of different techniques. A core diameter of about 250 nm with a 15 nm thick shell was revealed using TEM images. CSNPs were characterized by Fourier Transform Infrared (FTIR) spectroscopy, Transmission Electron Microscopy (TEM), and Thermogravimetric Analysis (TGA). Synthesized silicon oxide (silica) nanoparticles were functionalized with a hyperbranched polymer (HBP) achieving a core/shell nanoparticles (CSNPs) morphology.
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