Preparation of Hexagonal Boron Nitride-Containing Foam with Improved Thermal Conductivity of Epoxy Resins

Abstract

With the continuous development of electrical and electronic devices, the thermal conductivity of dielectric polymer composites within devices is becoming increasingly important. However, improving the thermal conductivity usually requires the incorporation of a large amount of filler in polymer material, which undoubtedly increases the production cost while destroying the processability and the dielectric properties of the material. In this work, an efficient heat transfer network was constructed inside the resin matrix to overcome this drawback. Using the opposite surface potentials of hexagonal boron nitride (h-BN) and polyethyleneimine (PEI) in solvent, h-BN was anchored on the surface of melamine foam (MF) by an electrostatic self-assembly technique to construct a thermal conductive skeleton with a three-dimensional open pore structure, and the corresponding epoxy (EP) composite was prepared by vacuum-assisted impregnation. This EP–MF@BN composite showed a significant increase in the heat arrival rate at an extremely low filler loading. At a h-BN loading of 2.1 wt %, the thermal conductivity of the composite reached 0.433 W/(m·K), which was 147% higher than that of the pure resin matrix. This is mainly attributed to the unique three-dimensional open-hole structure of the MF foam, which formed a three-dimensional frame structure with extremely low thermal resistance after anchoring by h-BN, thus providing a great degree of weakening of the scattering behavior during phonon transport. In addition, the transport behavior of carriers inside the composite under strong electric field conditions was analyzed in the current study. This strategy of constructing an efficient heat transfer network inside the polymer matrix provides an idea and method for the preparation of composites in the field of electrical insulation.

Thermally Conductive, Electrically Insulating Epoxy Pads with Three-Dimensional Polydopamine-Modified and Silver Nanoparticle-Functionalized Hexagonal Boron Nitride Networks

“…Numerous theoretical models have been developed to investigate the thermally conductive composites. , Among them, Foygel et al introduced a specialized thermal conductivity model tailored for high aspect ratio fillers, with a particular focus on the influence of ITR. This model can be expressed by the following equations: λ c − λ m = φ 0 true( V normalf − V normalc 1 − V normalc true) β R ′ = 1 φ 0 L V c β A = false( 2 D 2 / π false) ln true[ 1 − p − 1 + 1 + p − 1 1 + p − 1 − 1 − p − 1...…”

“…Numerous theoretical models have been developed to investigate the thermally conductive composites. , Among them, Foygel et al introduced a specialized thermal conductivity model tailored for high aspect ratio fillers, with a particular focus on the influence of ITR. This model can be expressed by the following equations: where λ c and λ m represent the TCs of the composite and EP, respectively.…”

Simultaneously Enhanced In-Plane and Out-of-Plane Thermal Conductivity of a PI Composite Film by Tetraneedle-like ZnO Whiskers and BN Nanosheets

“…At present, thermally conductive PI composites are commonly prepared by introducing highly thermally conductive fillers into the PI matrix to improve the thermal conductivity. The widely used thermally conductive fillers mainly include carbon nanotubes (CNTs), graphene, , microdiamond, alumina (Al 2 O 3 ), hexagonal boron nitride (BN), zinc oxide (ZnO), copper (Cu), aluminum nitride (AlN), silicon carbide (SiC), etc. The simple blending method is a general method for preparing polymer matrix composites with high thermal conductivity.…”

Orientation-Dependent Thermal and Mechanical Properties of 2D Boron Nitride Nanoplatelet Foams via Freeze-Drying

“…As a result, thermal and mechanical property control is impossible with this template-based approach. In addition, BN-based foams fabricated via chemical vapor deposition (CVD) ( k = 0.34 W/(m·K)) and self-assembly ( k = 0.18 W/(m·K)) have been reported in the literature. , However, these methods are highly complex, require high processing energy input, and have limited microstructure control.…”

“…In addition, BN-based foams fabricated via chemical vapor deposition (CVD) (k = 0.34 W/(m•K)) and self-assembly (k = 0.18 W/(m•K)) have been reported in the literature. 45,46 However, these methods are highly complex, require high processing energy input, and have limited microstructure control. Finally, it is important to note that studies that investigate the thermal, mechanical, and dielectric properties of BN-based foam-polymer composites have been reported in the literature.…”