Notch effect in clay-modified epoxy: a new perspective on nanocomposite properties

In this work, an experimental investigation of the notch effect on clay-modified epoxy resins is carried out, discussing the results from Single Edge Notch Bending tests and Double Edge Notch Tension tests on notched components. It is found that when the notch root radius is greater than a limit value, which depends on the clay content, the brittle failure of notched nanomodified specimens is controlled by the material strength. Under this circumstance nanomodification, while enhancing the polymer fracture toughness, might have a detrimental effect on the strength of notched components. This study brings to light a new feature of nanomodification according to which particular care should be used when using nanomodified resins for structural applications in the presence of notches or holes.