Document Type : Original Article
1 Iranian Space Research Center, Space Transportation Institute, Tehran, Iran
2 Tehran University, Tehran, Iran
3 Department of Chemical Engineering, Tehran University, Tehran, Iran
One of the methods for improving thermal conductivity of epoxy adhesives is the incorporating of conductive ceramic, metal or carbon fillers. As the main goal of this research, is to improve thermal conductivity of epoxy resin and keep its electrically insulating property, Alumina (Al2O3) ceramic filler, individually and in combination with Boron Nitride (BN) ceramic filler with high thermal conductivity and electrical resistivity. Scanning Electron Microscopy (SEM) observations showed a good dispersion and an acceptable connection between fillers. Thermal diffusivity measurements revealed that by incorporating conductive ceramic fillers, either individually or in combination with each other, regardless of the type of the hardener, thermal diffusivity would increase as a result of the formation of thermal conductive networks. Although, in hybrid system, because of bridging effect between particles, thermal diffusivity will notably increase. Therefore, using hybrid system of Alumina/BN along with long chain polyamine curing agent is a suitable choice for the preparation of thermally conductive yet electrically insulating epoxy adhesives in space industries. The results show that the thermal conductivity of hybrid system of Alumina/BN have been raised to 1.7 (W/mK) instead of 0.4 (W/mK) which is belong to pure epoxy system. The most important point of this work is that the good thermal conductivity obtained by kept of mechanical properties, dielectric constant, as well as lap shear strength of Alumina/BN hybrid system meet all acceptable range of thermal conductive adhesive for space application.