Morteza Ehsani - Iran polymer and petrochemical institute-Tehran-Iran
Zeinab Farhadinejad - Iran polymer and petrochemical institute,Tehran-Iran
Samad Moemen-bellah - Iran polymer and petrochemical institute,Tehran-Iran
Seyed Mohhamad Bagher alavi - Iran polymer and petrochemical institute,Tehran-Iran

More recently, epoxy-micro silica composites are used as insulators in dry type distribution transformers. Using of nano alumina particles in these composites is a strenuous topic of research due to effects of these nano particles on electrical, physical and thermal properties of such systems. Alumina, which is a hard spherical material, could be an appropriate option for reinforcing epoxy resin since it has properties like high stiffness, significant thermal conductivity and dielectric characteristic. The objective of the current paper is to investigate the influence of nano alumina particles on electrical, dynamic mechanical and thermal properties as well as morphological behavior of the cast epoxy/micro silica/nano alumina composite. To accomplish this purpose, different weight percent of nano alumina were added to the epoxy resin cured with anhydride type hardener and filled with micro silica. Then different tests including dielectric strength, loss factor and specific volume resistivity of prepared samples at different temperatures,

Nano alumina, cast epoxy system, dielectric strength, thermal stabilitydispersion of particles, Dynamic-mechanical properties