Abstract With the decreased sizes of microelectronic devices, the excess heat has become one of the most important factors that shorten the lifetime of electronic components. As a result, developing materials with high-thermal conductivity is an urgent issue. In this study, we combine an ultrasonic exfoliation and evaporated self-assembly methods to prepare boron nitride nanosheets (BNNS)/thermoplastic polyurethane (TPU) composites with small (S) and large (L) sizes connected BNNS as additives. Our results indicate that BNNS/TPU nanocomposites have better thermal conductivity than TPU, and the optimum performance is achieved at 10 wt% BNNS(S/L-1/9)/TPU. This enhanced thermal conductivity is ascribed to the successful construction of effective thermal conductive pathway. The S-BNNS is connected to the adjacent L-BNNS in TPU, which can also form a dense structure. The formation of the continuous thermal conductive pathways and networks structure facilitate the heat diffusion throughout the composites, which are the key to achieving high thermal conductivity in polymer composites. Furthermore, these results may be helpful to the deeper understanding for the combined structure of fillers in polymer matrix, which will expand the scope of applications for these materials.

中文翻译：

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通过设计小/大尺寸互连氮化硼纳米片提高聚氨酯复合材料的导热性

摘要 随着微电子器件尺寸的减小，过热已成为缩短电子元件寿命的最重要因素之一。因此，开发具有高导热性的材料是一个紧迫的问题。在这项研究中，我们结合超声剥离和蒸发自组装方法制备了氮化硼纳米片 (BNNS)/热塑性聚氨酯 (TPU) 复合材料，其中小 (S) 和大 (L) 尺寸连接 BNNS 作为添加剂。我们的结果表明，BNNS/TPU 纳米复合材料比 TPU 具有更好的导热性，并且在 10 wt% BNNS(S/L-1/9)/TPU 时达到最佳性能。这种增强的导热性归因于成功构建有效的导热路径。S-BNNS 连接到 TPU 中相邻的 L-BNNS，也可以形成致密的结构。连续导热通路和网络结构的形成促进了整个复合材料的热扩散，这是在聚合物复合材料中实现高导热性的关键。此外，这些结果可能有助于更深入地了解聚合物基体中填料的组合结构，这将扩大这些材料的应用范围。