The effects of multiple-sized compound fillers on the thermal, electrical, and processing properties of epoxy composites

作者：Yang, Wei; Zhao, Yushun^*; Chen, Yun; Qiao, Jian; Chen, Weijiang; Wang, Kun; Zhang, Chong; Zhang, Jin; Chen, Xin; Du, Bin

来源：Polymer Composites, 2024, 45(3): 2749-2758.

DOI：10.1002/pc.27954

• Al2O3
• compound fillers
• electrical properties
• epoxy composite
• thermal conductivity

The efficient filling of the multiple-sized compound fillers can effectively increase the thermal conductivity of the polymer composite. However, determining the specific proportion of the compound fillers with different sizes is hard. This article proposes a random distribution model and the closest packing model to calculate the proportion of the compound fillers and prepare the epoxy composites with different compound fillers. By elaborately designing epoxy composites containing 75 wt% (48 vol%) ternary compound Al2O3 fillers, its thermal conductivity reached 1.640 W/(m<middle dot>K). In addition, the volume resistivity for all prepared Al2O3/epoxy composites was higher than 10(16) Omega cm. Besides, the electrical and dielectric properties of the epoxy composite with multiple-sized compound fillers were comparable or superior to the composite with single-sized fillers. Last but not least, the viscosity of the ternary compound Al2O3/epoxy mixture was significantly lower than the single-sized Al2O3/epoxy mixture, which is beneficial for improving the processability of the epoxy composite. The results of this article will guide the development and utilization of epoxy composites with high thermal conductivities.