Highly thermally conductive polymer composite enhanced by constructing a dual thermal conductivity network

Abstract

Constructing interconnected thermally conductive networks in a polymer matrix is essential for efficient heat transport in thermally managed materials. Thermally conductive network structures typically have meager thermal resistance, and heat transfer into the material is rapidly exported along such networks. However, increasing the thermally conductive networks inside the polymer matrix is still challenging. This paper prepared high thermal conductivity composites with “primary‐secondary” thermal conductivity networks by combining two processes: constructing three‐dimensional thermally conductive skeletal networks and physically blending fillers, using epoxy resin as the matrix. The performance test results showed that the thermal conductivity of the composites reached 1.65 W/(m K) when the boron nitride (BN) content reached 33.5 wt%, which was 842.8% and 150% higher than that of pure epoxy (EP) and composites with randomly dispersed fillers. This highly efficient heat transfer behavior is mainly due to the synergistic effect of the two‐level thermally conductive network, which weakens the scattering effect of phonons to a great extent. Also, the dielectric properties of the composite material, especially the transport of carriers inside the material under strong electric fields, were discussed in this paper. This work provides ideas and methods for preparing electrical and electronic devices applied to high power density.

Multifunctional boron nitride nanosheets/fluorinated‐polyimide composites with ultra‐low dielectric constant and high thermal conductivity

“…In addition, the amorphous nature of polymer materials means that they have lack an effective thermal conduction path inside, which leads to the low thermal conductivity (TC). Thus, it is essential to establish an effective thermal conductivity network in polymer composites to enhance the heat dissipation 11,12 …”

Castor oil‐based polyurethane ternary composites with enhanced thermal conductivity and mechanical properties by using liquid metal as second filler

“…With the rapid development of the microelectronic technique towards higher packing and power density, thermal conductivity composites are playing an increasingly decisive role in the heat dissipation and lifespan extension of devices. [1][2][3][4][5][6][7] Polyurethane (PU)-based thermal conductivity composite has aroused deep concern due to its high mechanical properties. 8 However, one of the problems of PU is the petroleum feedstock, which leads to the depletion of fossil resources and aggravation of environmental problems.…”