Abstract The interface plays a key role in determining the properties of polymer composites. However, chemical inertness of hexagonal boron nitride (h-BN) makes its surface modification troublesome. In this study, we, for the first time, used SiO2 as the modified molecular and investigated the effects of exfoliated h-BN and SiO2 nanoparticles-modified-exfoliated h-BN (SiO2@exfoliated h-BN) on the storage modulus, the glass transition temperature, the filler dispersion and the thermal conductivity of polyvinyl alcohol (PVA) composites prepared by a solution mixture method. The results showed that the SiO2 modification enhanced the interface interaction and improved the performance of the PVA composites. Based on the enhanced interface interaction by SiO2 modification and the aligned fillers in PVA by vacuum filtration, the high thermal conductivity of 13.88 W/m·K was realized at 15.2 wt% SiO2@exfoliated h-BN loading. Meanwhile, the tensile strength was also largely improved to 156 MPa, compared with 47 MPa of pure PVA. This study broadens the surface modification method of h-BN and provides a valuable reference for fabrication of high-performance thermal interface materials.

中文翻译：

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基于SiO2纳米颗粒改性六方氮化硼增强界面的聚乙烯醇复合材料热传输和力学性能的大幅提高

摘要 界面在决定聚合物复合材料的性能方面起着关键作用。然而，六方氮化硼（h-BN）的化学惰性使其表面改性很麻烦。在这项研究中，我们首次使用 SiO2 作为改性分子，并研究了剥离 h-BN 和 SiO2 纳米颗粒改性剥离 h-BN（SiO2@exfoliated h-BN）对储能模量、溶液混合法制备的聚乙烯醇（PVA）复合材料的玻璃化转变温度、填料分散度和热导率。结果表明，SiO2改性增强了界面相互作用，提高了PVA复合材料的性能。基于SiO2改性增强的界面相互作用和真空过滤PVA中的排列填料，在 15.2 wt% SiO2@exfoliated h-BN 负载下实现了 13.88 W/m·K 的高热导率。同时，与纯 PVA 的 47 MPa 相比，拉伸强度也大大提高到 156 MPa。该研究拓宽了h-BN的表面改性方法，为高性能热界面材料的制备提供了有价值的参考。