Preparation And Properties Of Epoxy/Al₂O₃Nanocomposites

Epoxy resin is one of the most important thermosetting polymer materials. It hasmany excellent properties, such as high thermal stability, adhesion, me-chanical andelectrical properties. It is widely used in coating, adhesives, aero-space,microelectronic and electrical industries etc. However, it is well known that thecommonly used epoxy resin is rather brittle due to its highly cross linked structure.Its poor fracture toughness limits further application. The emergence of nano-particles provided new ways for modification of epoxy resin.In this dissertation, nano-Al₂O₃were successfully synthesized from aluminumisopropoxide（AIP） by hydrothermal process, and then epoxy/Al₂O₃nanocompositeswere prepared using methyl tetrahydro phthalic anhydride （MeTHPA） and1,2-methylimidazole （D-MI-1,2） as curing agent and cure accelerator by blendingprocess. The structure, fractured surface morphology, thermal stability, mechanicalproperties and dielectric properties of the hybrid materials were characterized.The results indicate that dielectric coefficient decreases with increasingfrequency and increases with increasing doping content, the dielectric loss increasesslightly with increasing frequency, but it is still remain a lower level. Dielectricstrength of the composites increases from17.04kV/mm to18.36kV/mm by addingAl₂O₃to3wt%.The impact strength and bending strength of the nano-composites first increasesand then decreases with the content increasing. The impact strength and bendingstrength of the nano-composites increase from11.78kJ·m-2,80.321MPa to17.23kJ·m-2,110.167MPa, respectively by adding Al₂O₃to7wt%. The thermal stability of the nano-composites first increases and then decreaseswith the content increasing. But it is still higher than that of the neat EP. When thecontent of the Al₂O₃particles is7wt%, the thermal stability reaches to408.7℃.