Thermal conductive and electrical insulating polymer composites are showing tremendous potential for modern electrical systems and electronic devices. Melt blending has been utilized as an effective technique to prepare thermal interface materials. However, during the process of melt-blending, strong π-π stacking and particle aggregation may be caused by thermal heating and local mechanical stress. Herein, ISP-PA6/BNNSs-OH (ISP-PN) composite has been fabricated by a masterbatch obtained via in-situ polymerization (ISP) and melt blending with polyamide-6 (PA6), with the incorporation of hydroxylated boron nitride nanosheets (BNNSs-OH). At the filler loading of 10 wt%, the through-plane thermal conductivity (TC) and Young's modulus of ISP-PN composites are respectively increased by 163% and 118%, compared to that of the neat PA6 resin. Prevailing over the matrix, the ISP-PN composites own volume electrical resistivity of ~5.11 × 10¹⁹ Ω cm. Meanwhile, the TC and mechanical properties of ISP-PN composites are 21.4% and 28.0% higher than the composites obtained by direct melt blending. The improved properties are attributed to the pre-disperse of filler through the masterbatch method. The PA6 chains were immobilized onto the BNNSs-OH by the condensation reaction, resulting in a sort of “chain-extender” and preventing the filler from re-aggregating during the process of melt-blending. This study pioneers a simple and versatile path to melt blending of thermally conductive polymer composites with good mechanical and electrical insulation properties in high-performance thermal management systems.

导热和电绝缘聚合物复合材料在现代电气系统和电子设备中显示出巨大的潜力。熔融共混已被用作制备热界面材料的有效技术。但是，在熔融共混过程中，热加热和局部机械应力可能会导致强烈的π-π堆积和颗粒聚集。在这里，ISP-PA6 / BNNSs-OH（ISP-PN）复合材料是通过将原位聚合（ISP）并与聚酰胺6（PA6）熔融共混并掺入羟基化氮化硼纳米片而获得的母料制成的（ BNNSs-OH）。填料含量为10 wt％时，与纯PA6树脂相比，ISP-PN复合材料的通面热导率（TC）和杨氏模量分别提高了163％和118％。¹⁹  Ω厘米。同时，ISP-PN复合材料的TC和力学性能比直接熔融共混得到的复合材料分别高21.4％和28.0％。改善的性能归因于通过母料方法对填料的预分散。通过缩合反应将PA6链固定在BNNSs-OH上，产生一种“扩链剂”，并防止填料在熔融共混过程中重新聚集。这项研究开创了一条简单而通用的途径，可以在高性能热管理系统中熔融共混具有良好机械和电绝缘性能的导热聚合物复合材料。