A series of flexible poly(m-phenylene isophthalamide) (PMIA)-based composites with different sizes and mass fractions of hexagonal boron nitride (hBN) were successfully manufactured for the first time via the casting technique. The effects of modified hBN particles on microstructure, mechanical properties, dielectric properties and thermal conductivities of fabricated composites were investigated. The results indicate that modified hBN particles manifest good compatibility with the PMIA matrix. The Young’s modulus and T_{heat-resistance index} of PMIA-based composites are increased with increasing the mass fraction of hBN particles. Due to additional thermal conductive paths and networks formed by nano-sized hBN particles, the K-m/n-hBN-30 composite displays the thermal conductivity of 0.94 W·m^-1·K^-1, higher than that of the K-m-hBN-30 composite (0.86 W·m^-1·K^-1), and more than 4 times higher than that of neat PMIA. Moreover, the obtained PMIA-based composites also show low dielectric constant and ideal dielectric loss. Owing to the excellent comprehensive performance, hBN/PMIA composites present potential applications in the broad field of electronic materials.

通过铸造技术首次成功地制造了一系列具有不同尺寸和质量分数的六方氮化硼（hBN）的柔性聚（间亚苯基间苯二甲酰胺）（PMIA）基复合材料。研究了改性hBN颗粒对复合材料的微观结构，力学性能，介电性能和热导率的影响。结果表明，修饰的hBN颗粒与PMIA基质表现出良好的相容性。PMIA基复合材料的杨氏模量和T_耐热指数随hBN颗粒质量分数的增加而增加。由于由纳米级hBN颗粒形成的其他导热路径和网络，Km / n-hBN-30复合材料的导热系数为0.94 W·m^-1 ·K ^-1，比Km-hBN-30复合材料（0.86 W·m ^-1 ·K ^-1）高，是纯PMIA的4倍以上。此外，所获得的基于PMIA的复合材料还显示出低介电常数和理想的介电损耗。由于出色的综合性能，hBN / PMIA复合材料在电子材料的广泛领域中具有潜在的应用前景。