The influence of high content nano-Al₂O₃ on the properties of epoxy resin composites

The nano-alumina (nano-Al₂O₃) particles were modified by silicon coupling agent KH-550, and the epoxy matrix nanocompo-sites were prepared by using nano-Al₂O₃ as reinforcing agent. The dispersion status was studied by transmission electron microscope (TEM). On this basis, effects of nano-Al₂O₃ content on dielectric and mechanical properties of the nanocomposites were studied. Morphologies of the fracture surface of nano-Al₂O₃/epoxy compo-sites were observed by scanning electron microscope (SEM). As a result, the mechanical properties reached to the best when the nano-Al₂O₃ content is 20%. The impact strength, flexural modulus and flexural strength increased by 84%, 29% and 18% respectively. The relative dielectric constant and the dielectric loss tangent were increased with nano-Al₂O₃ content.