This work shows how the properties of cured epoxy resins are improved significantly by the addition of surface-modified silica nanoparticles. Addition of nanosilica typically linearly increases both the modulus and the fracture toughness, and compressive strength and fatigue performance can be improved significantly as well. Combining this modification with the classic toughening concept using reactive liquid rubbers or core-shell elastomers leads to hybrid systems, which are characterized by high toughness and stiffness, with further-improved fatigue performance.
Laminates manufactured by using these modified resins exhibit improved performance as well. For the fatigue performance of laminates made from hybrid resins a tenfold increase in cyclic loadings upon failure can be achieved. This makes them especially suitable for highly stressed composites parts such as in automotive applications, aerospace, or wind energy.