Hypergravity-Induced Accumulation: A New, Efficient, and Simple Strategy to Improve the Thermal Conductivity of Boron Nitride Filled Polymer Composites.

Kangkang Yu,Songdi Zhang,Chenlu Bao,Tao Yuan

doi:10.3390/polym13030459

Kangkang Yu, Songdi Zhang + Show 2 more

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https://doi.org/10.3390/polym13030459

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Abstract

Thermal conductive polymer composites (filled type) consisting of thermal conductive fillers and a polymer matrix have been widely used in a range of areas. More than 10 strategies have been developed to improve the thermal conductivity of polymer composites. Here we report a new “hypergravity accumulation” strategy. Raw material mixtures of boron nitride/silicone rubber composites were treated in hypergravity fields (800–20,000 g, relative gravity acceleration) before heat-curing. A series of comparison studies were made. It was found that hypergravity treatments could efficiently improve the microstructures and thermal conductivity of the composites. When the hypergravity was about 20,000 g (relative gravity acceleration), the obtained spherical boron nitride/silicone rubber composites had highly compacted microstructures and high and isotropic thermal conductivity. The highest thermal conductivity reached 4.0 W/mK. Thermal interface application study showed that the composites could help to decrease the temperature on a light-emitting diode (LED) chip by 5 °C. The mechanism of the improved microstructure increased thermal conductivity, and the high viscosity problem in the preparation of boron nitride/silicone rubber composites, and the advantages and disadvantages of the hypergravity accumulation strategy, were discussed. Overall, this work has provided a new, efficient, and simple strategy to improve the thermal conductivity of boron nitride/silicone rubber and other polymer composites (filled type).

Highlights

With increasing integration and progressive miniaturization, electronic and energy storage devices need to dissipate heat with a high efficiency [1,2,3]
A hypergravity accumulation strategy has been developed to improve the thermal conductivity of polymer composites
The raw material mixtures of boron nitride (BN)/silicone rubber composites were treated in hypergravity fields (800–20,000 g) before heat-curing

Summary

Introduction

With increasing integration and progressive miniaturization, electronic and energy storage devices need to dissipate heat with a high efficiency [1,2,3]. Thermal conductive polymer composites (filled type) composed of a polymer matrix and thermal conductive fillers play an important role in the cooling systems in these areas. These composites are usually prepared by dispersing thermal conductive fillers in a polymer matrix with the techniques of in-situ polymerization, melting blending, and solvent blending, etc. They can be used in various ways such as for thermal interface materials, thermal conducting substrates, heat sinks, thermal conductive membranes, and thermal conducting shells Their practical applications cover a wide range of fields, including mobile phones, computers, appliances, electrical adaptors, batteries, transformers, base stations, and light-emitting diodes (LED), etc. The thermal conductivity is influenced by a range of factors, including thermal conductivity of polymeric matrix, thermal conductivity of fillers, filler

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