Material science
Sajede Aghasi; Seyed Hassan Jafari; Mahdi Golriz
Abstract
One of the methods for improving thermal conductivity of epoxy adhesives is the incorporation of conductive ceramic, metal or carbon fillers. As the main goal of this research is to improve the thermal conductivity of epoxy resin and keep its electrical insulating property, the effect of Alumina (Al2O3) ...
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One of the methods for improving thermal conductivity of epoxy adhesives is the incorporation of conductive ceramic, metal or carbon fillers. As the main goal of this research is to improve the thermal conductivity of epoxy resin and keep its electrical insulating property, the effect of Alumina (Al2O3) ceramic filler individually, and in combination with Boron Nitride (BN) ceramic filler with high thermal conductivity and electrical resistivity is investigated. Scanning Electron Microscopy (SEM) observations showed a proper dispersion and an acceptable connection between fillers. The results of the thermal diffusivity measurements revealed that by incorporating conductive ceramic fillers, either individually or in combination, regardless of the type of the hardener, thermal diffusivity would increase due to 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 showed that the thermal conductivity of hybrid system of Alumina/BN has raised to 1.7 (W/mK), which is about 0.4 (W/mK) for epoxy system without filler. The most important achievement of this research is to achieve proper thermal conductivity while keeping mechanical properties, dielectric constant, and lap shear strength of Alumina/BN hybrid system within acceptable range of thermal conductive adhesive for space applications
