Abstract Hexagonal boron nitride (h-BN) nanoplatelets (0.6 μm in diameter and 100 nm in thickness) are introduced into epoxy resin to improve the polymer’s thermal conducting ability. As expected, the thermal conductivities (TCs) of the composites, especially the in-plane TCs, are significantly increased. The in-plane TC of the epoxy composites can reach 1.67 W/mK at only 0.53 wt% loading, indicating h-BN nanopletelets are very effective thermal fillers. However, after carefully studied the correlation of the TC improvement and filler content, a sudden drop of the TC around 0.53 wt% filler loading is observed. Such an unexpected decrease in TC has never been reported and is also found to be consistent with the T g changes versus filler content. Similar trend is also observed in other 2-D nanofillers, such as graphene oxide, reduced graphene oxide, which may indicate it is a general phenomenon for 2-D nanofillers. SEM results suggest that such sudden drop in TC might be coming from the enrichment of these 2-D nanofillers in localized areas due to their tendency to form more ordered phase above certain concentrations.

中文翻译：

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氮化硼纳米片作为环氧树脂复合材料中的二维热填料：极低填料负载下的新场景

摘要 将六方氮化硼（h-BN）纳米片（直径0.6 μm，厚度100 nm）引入环氧树脂中以提高聚合物的导热能力。正如预期的那样，复合材料的热导率 (TC)，尤其是面内 TC，显着增加。环氧树脂复合材料的面内 TC 在仅 0.53 wt% 的负载量下就可以达到 1.67 W/mK，表明 h-BN 纳米片是非常有效的热填料。然而，在仔细研究了 TC 改进和填料含量的相关性后，观察到 TC 突然下降约 0.53 wt% 填料负载。从未报道过这种意外的 TC 降低，并且还发现这与 T g 变化与填料含量的关系一致。在其他二维纳米填料中也观察到类似的趋势，例如氧化石墨烯、还原氧化石墨烯、这可能表明这是二维纳米填料的普遍现象。SEM 结果表明 TC 的这种突然下降可能来自这些 2-D 纳米填料在局部区域的富集，因为它们倾向于在高于特定浓度时形成更有序的相。