基于双动态网络的导热自修复石墨烯/聚脲复合材料

A graphene/polyurea composite with both thermal conduction and self-healing functions based on dual dynamic networks

  • 摘要: 开发能够快速修复的导热材料引起了越来越多的关注。然而,材料的导热性能与自修复性能一直难以平衡,制备具有自愈性的导热聚脲复合材料具有挑战性。为了解决这一难题,本论文提出利用氢键和动态亚胺键的双动态网络构筑自修复聚脲(D-PUA)柔性膜。氢键和亚胺键的动态断裂和重构不断耗散能量,使D-PUA具有良好的弹性和自修复性。实验结果表明,在短时间内(60 ℃、8 min) D-PUA膜上的划痕可完全修复,切断愈合72 h后拉伸强度的修复效率为84.62%。在动态聚脲基体中填充石墨烯(GNP)制备得到兼具自修复、导热性和可回收性的GNP/D-PUA复合膜。基于GNP本身的高导热性,负载量为10 wt%时,复合膜的面内导热系数为2.57 W·m−1·K−1,相对于本征膜提升了571%。GNP10/D-PUA在90 ℃,60 min能够使划痕愈合,切断愈合72 h后拉伸强度的修复效率为83.94%。此外,由于动态键的存在复合膜经过五次热压重塑后,没有明显的机械损失,且面内热导率的回复率均在80.93%以上。

     

    Abstract: The development of thermal conductivity materials that can be quickly repaired has attracted increasing attention. However, due to the trade-off between thermal conductivity and self-healing properties of materials, it is challenging to prepare thermal conductivity polyurea composites with self-healing properties. To solve this problem, this paper proposes to construct self-healing polyurea (D-PUA) flexible membrane by using the double dynamic network of hydrogen bonds and dynamic imine bonds. The dynamic breaking and reconstruction of hydrogen bonds and imine bonds dissipates energy continuously, which makes D-PUA have good elasticity and self-repair. The experimental results demonstrate that scratches on the D-PUA film can be completely repaired in a short time (60 ℃, 8 min), and the repair efficiency of tensile strength reaching 84.62% after 72 h of cutting and healing. The GNP/D-PUA composite membrane with self-healing, thermal conductivity and recyclability was prepared by incorporating graphene (GNP) as a filler. Due to the high thermal conductivity of graphene itself, the in-plane thermal conductivity of the composite film is 2.57 W·m−1·K−1 when the GNP content is 10 wt%, which is 571% higher than that of the pure film. GNP10/D-PUA can also heal scratches at 90 ℃ for 60 min, and the repair efficiency of tensile strength after 72 h of cutting and healing is 83.94%. Additionally, due to the presence of dynamic bonds, there is no significant mechanical loss after five hot pressing remodeling of the composite film, and the repair rate of in-plane thermal conductivity is above 80.93% in all cases.

     

/

返回文章
返回