Polymers and composites with high thermal conductivity are promising yet challenging for the growing demand of thermal management in electrical and electronic equipment. Guided by the closest packing model, a multiscale filling Al₂O₃ strategy was designed and incorporated with epoxy resin (EP) to form high thermal conductive composites in this work. Epoxy composites with single filler loading were also prepared. The microstructures, thermal, rheological, and dielectric characteristics of the multiscale filling Al₂O₃/EP composites have been investigated. Compared with single-scale Al₂O₃ filled epoxy based composites, it is found that the multiscale filling Al₂O₃/EP composites exhibit higher thermal conductivity under the same filler loading of 50 vol %, which is attributed to the efficient heat conduction paths formed by appropriate multiscale fillers. Particularly, a remarkably improved thermal conductivity of 2.707 W m⁻¹ K⁻¹ was acquired in Al₂O₃/EP composites at filler loading of 50 vol% (5 μm Al₂O₃ (26.67 vol%), 30 μm Al₂O₃ (27.41 vol%) and 70 μm Al₂O₃ (45.92 vol%)), which is about 1300% higher than that of the pure epoxy resin. In addition, the dielectric constant of the Al₂O₃/EP composites were significantly improved while keeping the dielectric loss almost unchanged. The finite element simulation further verified the effectiveness of improving the thermal conductivity of materials in the heat dissipation of electrical equipment. Therefore, this research provides a simple strategy for manufacturing high thermal conductive composite materials with a wide range of potential applications as packaging materials.

对于电气和电子设备中日益增长的热管理需求，具有高导热性的聚合物和复合材料很有前景，但也具有挑战性。在最密堆积模型的指导下，设计了一种多尺度填充Al ₂ O ₃策略，并与环氧树脂（EP）结合形成高导热复合材料。还制备了具有单一填料负载的环氧树脂复合材料。_{研究了多尺度填充Al 2} O ₃ /EP 复合材料的微观结构、热学、流变学和介电特性。与单尺度Al ₂ O ₃填充环氧树脂基复合材料相比，发现多尺度填充Al ₂O ₃ /EP 复合材料在 50 vol% 的相同填充量下表现出更高的热导率，这归因于适当的多尺度填料形成的有效热传导路径。特别是在填充量为 50 vol%（5 μm Al 2 O ₃ ⁽ _26.67 vol _% ⁾  、₃₀ μm Al ₂ O ₃ (27.41 vol%)和70 μm Al ₂ O ₃ (45.92 vol%))，比纯环氧树脂高约1300%。_{此外，Al 2} O的介电常数₃ /EP 复合材料在保持介电损耗几乎不变的情况下得到了显着改善。有限元仿真进一步验证了提高材料导热系数在电气设备散热中的有效性。因此，本研究为制造具有广泛潜在应用的高导热复合材料作为包装材料提供了一种简单的策略。