A comparative study on thermal conductivity and permittivity of composites based on linear low-density polyethylene and poly(lactic acid) filled with hexagonal boron nitride

Thermal conductivity (lambda) and permittivity (epsilon ') of polymer composites based on linear low-density polyethylene (LLDPE) and poly(lactic acid) (PLA) filled with hexagonal boron nitride (hBN) were considered in this work. It is found that all developed composites possess dielectric properties and enhancement thermal conductivity compared with neat polymer matrices. Unlike carbonaceous materials (carbon black, graphite, graphene, carbon nanotubes), hBN is a good insulator and is therefore more applicable as a filler for heat-releasing materials with a purely white appearance. At the same time, both LLDPE/hBN and PLA/hBN composites at 40 wt% filler content possess the comparable value of lambda about 0.7 W/(m K), which is almost 95% and 250% higher than those for the neat LLDPE and PLA, respectively.