Abstract Different from traditional compounding methods, a conversion method from “sand-like” to “stone-like” conductive network aimed at improving the thermal conductivity (TC) of polymer composites was proposed in this paper. Herein, “sand-like” and “stone-like” channels represented the thermal conductive networks (TCNs) with high and low thermal dissipation performances in polymer composites. The densification of TCNs and the adding of specific rigid particles were found to be two effective ways to realize the conductive network conversion from “sand-like” to “stone-like”. In this research, the polydimethylsiloxane/short carbon fiber/glass bubble (PDMS/SCF/GB) composite was selected to verify the practicability of this conversion theory. The SCF contents changed from 10 to 30 wt% to reveal the influence of filling content on the sand-stone conversion of TCNs. A constant content of 2 wt% GBs was selected based on our previous experience to highlight the beneficial effect of adding rigid particles. Meanwhile, the influence of product thickness on the PDMS composites was also systematically investigated. The TC of PDMS/SCF/GB composite with 0.1 mm thickness reached 11.690 W/m·K, 42.30 times higher than that of pure PDMS (0.27 W/m·K). Moreover, the superior flexibility and mechanical property of final product provided convenience for their application as thermal management materials in electronics.

中文翻译：

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通过在聚二甲基硅氧烷复合材料中从“沙状”到“石状”的导电网络转换来增强导热性

摘要 与传统的复合方法不同，本文提出了一种以提高聚合物复合材料的导热系数（TC）为目标的由“沙状”到“石状”导电网络的转换方法。在此，“沙状”和“石状”通道代表了聚合物复合材料中具有高和低散热性能的导热网络（TCN）。研究发现，TCNs的致密化和特定刚性粒子的加入是实现导电网络从“沙状”到“石状”的两种有效方式。本研究选择聚二甲基硅氧烷/短碳纤维/玻璃泡（PDMS/SCF/GB）复合材料来验证该转化理论的实用性。SCF 含量从 10 到 30 wt% 变化以揭示充填量对 TCN 砂石转化率的影响。根据我们之前的经验，选择了 2 wt% GB 的恒定含量，以突出添加刚性颗粒的有益效果。同时，还系统地研究了产品厚度对PDMS复合材料的影响。0.1 mm 厚的 PDMS/SCF/GB 复合材料的 TC 达到 11.690 W/m·K，是纯 PDMS（0.27 W/m·K）的 42.30 倍。此外，最终产品的优异柔韧性和机械性能为其作为电子热管理材料的应用提供了便利。还系统地研究了产品厚度对 PDMS 复合材料的影响。0.1 mm 厚的 PDMS/SCF/GB 复合材料的 TC 达到 11.690 W/m·K，是纯 PDMS（0.27 W/m·K）的 42.30 倍。此外，最终产品的优异柔韧性和机械性能为其作为电子热管理材料的应用提供了便利。还系统地研究了产品厚度对 PDMS 复合材料的影响。0.1 mm 厚的 PDMS/SCF/GB 复合材料的 TC 达到 11.690 W/m·K，是纯 PDMS（0.27 W/m·K）的 42.30 倍。此外，最终产品的优异柔韧性和机械性能为其作为电子热管理材料的应用提供了便利。