Polymer‐based nanocomposites with ultra‐high in‐plane thermal conductivity via highly oriented boron nitride nanosheets

Abstract

Novel polymer‐based materials with highly thermally conductive and high‐mechanical properties have attracted extensive attention in the field of electronic packaging as thermal interface materials (TIMs), due to the development of electronic equipment to miniaturization and higher power density. However, how to achieve high‐thermal conductivity (exceed 5 W/m·K) with low‐filling content (below 30 vol%) is still the focus of attention. Herein, polymer‐based materials with excellent in‐plane thermal conductivity were prepared by a simple hot‐pressing strategy, and a series of nanocomposites with different orientations were controlled by the hot‐pressing times. As expected, compared with that of randomly dispersed 25 vol% BNNS/P(VDF‐HFP) nanocomposite and pristine P(VDF‐HFP), the in‐plane thermal conductivity of oriented 25 vol% BNNS/P(VDF‐HFP) is promoted by 249% and 3057%, respectively. In contrast to randomly dispersed composites, oriented BNNS/P(VDF‐HFP) at loadings above 10 vol% begin to show an encouraging upward trend. This is because the orientation of BNNS can significantly reduce the percolation threshold and construct an efficient heat conduction network under low‐filling volume. Therefore, this technology can provide new ideas for the development of electronic packaging technology.

AWI-Assembled TPU-BNNS Composite Films with High In-Plane Thermal Conductivity for Thermal Management of Flexible Electronics

“…Hence, this architecture rendered the composite with a high in-plane thermal conductivity. In traditional methods, such as solution casting, most nanofillers were randomly dispersed into the polymer matrix, and more phonon scattering occurred at the interfaces of adjacent fillers with a small contact area, as well as poor compatibility and mismatch at filler–polymer interfaces . In addition, the in-plane thermal conductivity of the AWI-assembled TPU-BNNS nanocomposite film with 30 wt % BNNSs was tested under repeating heating and cooling cycles between 25 and 100 °C, as shown in SI, Figure S8, exhibiting a good thermal stability.…”

“…In traditional methods, such as solution casting, most nanofillers were randomly dispersed into the polymer matrix, and more phonon scattering occurred at the interfaces of adjacent fillers with a small contact area, as well as poor compatibility and mismatch at filler−polymer interfaces. 39 In addition, the inplane thermal conductivity of the AWI-assembled TPU-BNNS nanocomposite film with 30 wt % BNNSs was tested under repeating heating and cooling cycles between 25 and 100 °C, as shown in SI, Figure S8, exhibiting a good thermal stability. Moreover, to further evaluate the potential of the composite for the thermal management of flexible/stretchable electronics, the in-plane thermal conductivity of the AWI-assembled TPU-BNNS composite film with 30 wt % BNNSs was assessed under cyclic mechanical bending and stretching, as shown in Figure 2c.…”

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

“…Usually, fillers with high thermal conductivity, such as aluminum nitride (AlN), 15 boron nitride (BN), 16–18 alumina (Al 2 O 3 ), 19 graphene, 20,21 and diamond, 22,23 are incorporated into polymeric materials as thermally conductive fillers and the thermal conductivity of polymeric materials can be enhanced by physical blending. This approach is considered the easiest way to enhance the thermal conductivity of polymeric materials 24–27 .…”

Epoxy composites with high thermal conduction routes via in situ constructing “pea‐pod‐like” alumina‐boron nitride 3D structure

“…[19][20][21] So far, graphene, aluminum oxide (Al 2 O 3 ), and boron nitride (BN) have been widely used to improve the thermal conductivity of polymers due to their excellent thermal management behavior. [22][23][24][25][26][27][28][29][30][31] However, traditional methods, such as simple blending, make their enhancement of the thermal conductivity of polymers extremely limited due to the difficulty of forming effective thermal conductivity networks and the great interfacial thermal resistance between thermally conductive fillers and polymers.…”