Fracture Toughening Mechanisms in Epoxy Adhesives

Fracture toughness is generally considered as the main properties of a polymer or apolymer adhesive system for measuring the material resistance to the extension ofcracks. Epoxy adhesives are generally brittle in nature; however, the addition of a seconddispersed phase could induce a remarkable increase of damage tolerance performanceby an enhancement of the material fracture toughness. The fracture behavior of a filledepoxy resin is strongly affected by the dimensions, the shape, and the chemical natureof the considered filler? The chapter describes the different toughening mechanisms forpolymer adhesives with special attention toward innovative nanofiller such as graphenenanoplatelets and hyperbranched polymer nanoparticles.