Preparation and properties of Al_2O_3 nanosheets/epoxy composites

Al2O3nanosheets were successfully synthesized by hydrothermal process.After modified with coupling agent,Al2O3nanosheets/epoxy composites with different contents of Al2O3 nanosheets were prepared by solution mixing.The effects of Al2O3 nanosheet content on the dielectric and thermal properties of Al2O3nanosheets/epoxy composites were discussed.The fracture morphology of composites was characterized by SEM.The results show that Al2O3 nanosheets uniformly disperse in epoxy matrix.With the increase of Al2O3 nanosheet content,the initial thermal decomposition temperature and the dielectric strength of Al2O3nanosheets/epoxy composites increase.Dielectric strength of composites is 29.58kV/mm with 7wt% Al2O3 adding,which is increased by 30%than that of the pure epoxy.Dielectric constant(3.8-4.5)and dielectric loss(0.015)of Al2O3nanosheets/epoxy composites increase slightly than pure epoxy's,but the dielectric properties still remain at a good level.