The polymer/hexagonal boron nitride (h-BN) thermal conductive composite an excellent candidate for thermal management materials due to its insulation properties. However, it is a challenge to achieve efficient large-scale exfoliation of h-BN through melt blending to balance thermal conductivity and mechanical properties. In this work, an innovative melt mixing strategy using the co-rotating non-twin screw extruder (NTSE) was developed to prepare the high-density polyethylene (HDPE)/h-BN composites with excellent overall performance. The results were well compared with those of conventional twin screw extruder (TSE). The NTSE triggers chaotic mixing and provides a strong elongation flow field capable of h-BN efficiently exfoliating into a few layers, while simultaneously ensuring uniform dispersion and distribution within HDPE. The in-plane thermal conductivity and elongation at break of the NTSE composite with 10 wt% h-BN addition were 7.63 W∙m−1 K−1 and 653.1 %, which were 74.7 % and 70.3 % higher than those prepared by TSE, while the enhancement rates rose to 174.6 % and 74.4 % when 30 wt% h-BN was added, respectively. The in-plane thermal conductivity enhancement ratio of NTSE was more than 3000 % when the h-BN content was higher than 10 wt%. Besides, the thermal stability, crystallinity, and thermal diffusion of the NTSE composites were also enhanced to different degrees. This strategy is efficient to coordinating the conflicting between the comprehensive performance and large-scale preparation of thermally conductive polymer composites.

中文翻译：

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一种新型熔融挤出方法，用于高效、大规模原位剥落氮化硼制备高性能导热聚合物复合材料


聚合物/六方氮化硼 （h-BN） 导热复合材料由于其绝缘性能而成为热管理材料的绝佳候选者。然而，通过熔融混合实现 h-BN 的高效大规模剥离以平衡导热性和机械性能是一项挑战。在这项工作中，开发了一种使用同向旋转非双螺杆挤出机 （NTSE） 的创新熔融混合策略，以制备具有优异整体性能的高密度聚乙烯 （HDPE）/h-BN 复合材料。与传统的双螺杆挤出机 （TSE） 相比，结果得到了很好的比较。NTSE 触发混沌混合并提供强大的伸长流场，能够使 h-BN 有效地剥离成几层，同时确保在 HDPE 内均匀分散和分布。添加 10 wt% h-BN 的 NTSE 复合材料的面内热导率和断裂伸长率分别为 7.63 W∙m−1 K−1 和 653.1 %，分别比 TSE 制备的提高了 74.7 % 和 70.3 %，而当添加 30 wt% h-BN 时，增强率分别上升到 174.6 % 和 74.4 %。当 h-BN 含量高于 10 wt% 时，NTSE 的面内导热系数增强率超过 3000 %。此外，NTSE 复合材料的热稳定性、结晶度和热扩散也得到了不同程度的增强。该策略可以有效地协调导热聚合物复合材料的综合性能与大规模制备之间的冲突。