High Thermal Conductive Natural Rubber Composites Using Aluminum Nitride and Boron Nitride Hybrid Fillers

Herein, we investigated the thermal conductivity and thermal stability of natural rubber composite systems con­taining hybrid fillers of boron nitride (BN) and aluminum nitride (AlN). In the hybrid system, the bimodal distribution of polygonal AlN and planar BN particles provided excellent filler-packing efficiency and desired energy path for phonon transfer, resulting in high thermal conductivity of 1.29 W/mK, which could not be achieved by single filler composites. Fur­ther, polyethylene glycol (PEG) was compounded with a commonly used naphthenic oil, which substantially increased ther­mal conductivity to 3.51 W/mK with an excellent thermal stability due to facilitated energy transfer across the filler-filler interface. The resulting PEG-incorporated hybrid composite showed a high thermal degradation temperature (T2) of 290℃, a low coefficient of thermal expansion of 26.4 ppm/℃, and a low thermal distortion parameter of 7.53 m/K, which is well over the naphthenic oil compound. Finally, using the Fourier''s law of conduction, we suggested a modeling methodology to evaluate the cooling performance in thermal management system.