In this work, carbon nanotubes pillared grew on exfoliated graphite by the microwave-assisted method is utilized as thermally conductive fillers (CPEG) in polyimide (PI) to fabricate CPEG/PI thermally conductive composites with the combining ways of “in-situ polymerization, electrospinning, lay-up, and hot-pressing”. The prepared CPEG/PI composites realized the maximum thermal conductivity (λ, 1.92 W m⁻¹ K⁻¹) at low CPEG amount (10 wt%), much higher than that of pure PI (0.28 W m⁻¹ K⁻¹). The λ of CPEG/PI composites show almost no change after 1000 cycles of heating and cooling at the temperature of 25−100 °C. The finite element analysis simulates the nano-/microscale heat transfer in CPEG/PI composites to reveal the internal reason of the λ enhancement. The improved thermal conductivity model and empirical equation could better reflect the actual λ change trend of CPEG/PI composites. The actual application test shows the CPEG/PI composites could significantly reduce the operating temperature of the CPU in mobile phone.

在这项工作中，通过微波辅助方法在剥离石墨上柱状生长的碳纳米管作为聚酰亚胺（PI）中的导热填料（CPEG），通过“原位聚合，静电纺丝、叠层和热压”。制备的 CPEG/PI 复合材料在低 CPEG 用量（10 wt%）下实现了最大热导率（λ , 1.92 W m ^-1 K ^-1），远高于纯 PI（0.28 W m ^-1 K ^-1） . 该λCPEG/PI 复合材料在 25-100 °C 的温度下经过 1000 次加热和冷却循环后几乎没有变化。有限元分析模拟了 CPEG/PI 复合材料中的纳米/微米级传热，以揭示λ增强的内部原因。改进后的热导率模型和经验方程可以更好地反映CPEG/PI复合材料的实际λ变化趋势。实际应用测试表明，CPEG/PI复合材料可以显着降低手机CPU的工作温度。