Thermal Conductivity of Epoxy Composite Consisting of Hybrid Boron Nitride Nano Sheets and Nano Spheres

Enhancement of thermal conductivity of polymer materials has many potential applications in the industry such as thermal interface materials, electronic packaging and electronic substrates. In this work thermal conductivity of epoxy composite with hybrid filler of 2 dimensional boron nitride nano sheets and 0 dimensional boron nitride nano spheres has been investigated up to 0.5 volume loading. It was shown that in the higher filler loading range hybrid filler shows completely different behavior in thermal conductivity compared to single filler. Synergistic effect in thermal conductivity enhancement was observed in lower filler loading range (<10% volume), however for higher loading fraction synergistic effect in thermal conductivity enhancement was absent. In addition it was observed that percolation threshold changes from 0.25 volume loading for pure boron nitride nano sheet to 0.15 volume loading for hybrid boron nitride nano sheets and boron nano spheres. Our results provide better understanding in mechanism of thermal conductivity enhancement for composite materials.

Keywords:

Thermal conductivity , Epoxy composite , Boron nitride nanoparticles , Thermal percolation