Traditional methods to overcome the challenges associated with the low thermal conductivities (TCs) of polymer composites range from constructing a continuous filler network to minimizing interface resistance. However, the improvement in the TCs of polymer composites is still limited. A key reason is that the polymer among the filler gaps causes high thermal losses and induces thermal resistance for phonons, as the filler network formed by conventional methods is not compact. Herein, a novel forced compression method, induced by compressing the thicknesses of samples to less than their critical thicknesses in a confined space, was applied to construct a robust network to significantly improve the TCs of polymer composites. Aluminum nitride (AlN) ranging from 0 to 54 wt% was added into polydimethylsiloxane (PDMS) to prepare composites using this method. The enhancement in the TCs of AlN/PDMS composites included several considerations: high compression ratio and filler content both led to a small gap between the fillers in the filler network; the improvement in TC was significantly higher, especially at low filler contents, which simultaneously ensured the mechanical properties of polymer composites. Owing to the gap‐cut behavior, the TC was enhanced to 2.667 W/(mK) at 54 wt% of AlN, which was significantly higher than those in the literature results. The AlN/PDMS sample was then utilized as a heat spreader to decrease the temperature of heat source. The temperature dropped 14.42°C more than pure PDMS sheet. This novel compression process provides a facile approach to prepare light‐weight polymer composites with high TCs.

中文翻译：

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通过调整填料网络中的热损失来提高氮化铝-聚二甲基硅氧烷复合材料的导热性

克服与聚合物复合材料的低导热率（TC）相关的挑战的传统方法，从构造连续的填料网络到最小化界面电阻，应有尽有。然而，聚合物复合材料的TCs的改善仍然是有限的。关键原因在于，由于常规方法形成的填料网络不致密，因此填料间隙中的聚合物会导致较高的热损失并引起声子的热阻。在本文中，通过在有限的空间中将样品的厚度压缩到小于其临界厚度而引入的一种新颖的强制压缩方法，被用于构建坚固的网络以显着提高聚合物复合材料的TCs。将范围为0至54 wt％的氮化铝（AlN）添加到聚二甲基硅氧烷（PDMS）中，以使用此方法制备复合材料。AlN / PDMS复合材料的TCs增强包括以下几个方面的考虑：高压缩比和填料含量均导致填料网络中填料之间的缝隙变小；TC的改善明显更高，尤其是在填料含量低的情况下，这同时确保了聚合物复合材料的机械性能。由于间隙切割行为，在AlN含量为54 wt％时，TC增强到2.667 W /（mK），大大高于文献结果。然后将AlN / PDMS样品用作散热器，以降低热源的温度。温度比纯PDMS片材下降了14.42°C。