Abstract
Fracture toughness and other mechanical properties of epoxies modified with nano-slica
particles were measured to elaborate effects of nano-additives on fracture behaviour of the modified
epoxies. Interlaminar fracture behaviours of the nano-silica modified CF/EP composites were
subsequently investigated by conducting Mode-I and Mode-II interlaminar fracture toughness tests as
well as transverse tension tests. It was found that the fracture toughness of the nano-silica modified
epoxies and the interlaminar fracture toughness of nano-silica modified CF/EP composites have been
increased significantly (>50%), while the strength and modulus of the materials remain unchanged or
slightly higher. In particular, the nano-silica modified epoxies showed only very little reduction in the
glass transition temperature (Tg).