Factors affecting thermal conductivities of the polymers and polymer composites: A review

Thermal transport in polymeric materials and across composite interfaces

Construction of multifunctional boron nitride nanosheet towards reducing toxic volatiles (CO and HCN) generation and fire hazard of thermoplastic polyurethane

The effective dissipation of heat is critical to the performance and longevity of high-power electronics, so it is important to prepare highly thermally conductive polymer-based packaging materials for efficient thermal management. Due to the excellent thermal conductivity of boron nitride nanosheets (BNNSs), the hexagonal boron nitride (hBN) powder was dissolved in a mixed solution of isopropanol and deionized water for ultrasonic exfoliation to obtain hydroxylated BN nanosheets. Then, the prepared BNNS was functionalized with (3-aminopropyl)triethoxysilane (APTES) to enhance its dispersibility and interfacial compatibility in the epoxy resin, which play an important role in the improvement of the thermal conductivity of the composites. Finally, APTES-BNNS was uniformly dispersed in the epoxy resin by solvent mixing, and the oriented APTES-BNNS/epoxy composites were prepared through spin-coating and hot-pressing methods. It was found that APTES-BNNS/epoxy composites prepared herein exhibited significant anisotropic thermal conductivity. The results show that the thermal conductivity of APTES-BNNS/epoxy composites reached 5.86 W/mK at a filler content of 40 wt % and these composites have favorable thermal stability and mechanical properties. The APTES-BNNS/epoxy composite prepared in this paper has excellent thermal management capability and can be applied to the packaging of high-power electronic devices.

Novel Functionalized BN Nanosheets/Epoxy Composites with Advanced Thermal Conductivity and Mechanical Properties.

Polymer-based thermal management materials have many irreplaceable advantages not found in metals or ceramics, such as easy processing, low density, and excellent flexibility. However, their limited thermal conductivity and unsatisfactory resistance to elevated temperatures ( 100 MPa, 450 °C) enable effective thermal management for microelectrodes operating at temperatures beyond 200 °C.

Highly Thermoconductive, Thermostable, and Super-Flexible Film by Engineering 1D Rigid Rod-Like Aramid Nanofiber/2D Boron Nitride Nanosheets.

A facile strategy was reported to fabricate vertically oriented and densely packed hexagonal boron nitride (h-BN)/epoxy (EP) composites via vacuum filtration followed by slicing up. This route is simple and high-efficient without special treatment and/or chemical modification. A high through-plane thermal conductivity of 9 W/m K was obtained at a h-BN loading of 44 vol% in the composites. Laser flash thermal analyzer (LFA) and thermogravimetric analysis (TGA) results indicated that the through-plane thermal conductivity of the composites increased with the fraction of the fillers. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) tests indicated that h-BN microplatelets were mainly vertically oriented in the composites. In addition, as-made composites showed good mechanical strength. Therefore, it has great potential as thermal interface materials, which is very important in the thermal management of electronics, especially in electronic packages where electrical insulation is required.

Xiaodong Fan

Papers

Enhanced through-plane thermal conductivity of boron nitride/epoxy composites

Hot-pressing induced alignment of boron nitride in polyurethane for composite films with thermal conductivity over 50 Wm −1 K −1