中南民族大学张俊珩团队开发了基于二硫缩醛共价自适应网络的，可回收高性能碳纤维增强环氧复合材料。相关研究成果于2024年8月27日发表在《中国高分子科学杂志》。

碳纤维增强复合材料的回收利用对可持续发展和循环经济具有重要意义。尽管使用了动态化学，但由于材料的动态和机械性能之间的互斥性，开发高强度可回收CFRPs仍然是一个重大挑战。

该文中，研究人员开发了一种基于动态二硫代缩醛共价自适应网络的高强度可回收环氧树脂（HREPs），该网络使用二缩水甘油醚双酚a（DGEBA）、季戊四醇四（3-巯基丙酸酯）（PETMP）和香草醛环氧树脂（VEPR）。在高温下，热活化二硫代缩醛的交换反应加速了网络的重排，使其具有显著的再加工能力。

由于交联密度增加，HREP表现出优异的耐溶剂性。以这种高强度可回收环氧树脂为基体，以超支化离子液体（HBP-AMIM+PF₆^-）改性的碳纤维为增强剂，成功制备了高性能碳纤维复合材料。优化配方（HREP20/CF-HBPPF₆）的拉伸强度、界面剪切强度（IFSS）和层间剪切强度（ILSS）分别为1016.1、70.8和76.0 MPa。

此外，CFRPs表现出优异的耐溶剂性和耐酸碱性。CFRPs可以在140°C的DMSO中在24小时内完全降解，经过多次降解循环后，回收的CF仍保持与原始CF相同的拉伸强度和ILSS。

附：英文原文

Title: Recyclable High-performance Carbon Fiber Reinforced Epoxy Composites Based on Dithioacetal Covalent Adaptive Network

Author: Gui-Lian Shi, Ting-Cheng Li, Dao-Hong Zhang, Jun-Heng Zhang

Issue&Volume: 2024-08-27

Abstract: Recycling of carbon fiber reinforced composites is important for sustainable development and the circular economy. Despite the use of dynamic chemistry, developing high-strength recyclable CFRPs remains a major challenge due to the mutual exclusivity between the dynamic and mechanical properties of materials. Here, we developed a high-strength recyclable epoxy resin (HREP) based on dynamic dithioacetal covalent adaptive network using diglycidyl ether bisphenol A (DGEBA), pentaerythritol tetra(3-mercapto-propionate) (PETMP), and vanillin epoxy resin (VEPR). At high temperatures, the exchange reaction of thermally activated dithioacetals accelerated the rearrangement of the network, giving it significant reprocessing ability. Moreover, HREP exhibited excellent solvent resistance due to the increased cross-linking density. Using this high-strength recyclable epoxy resin as the matrix and carbon fiber modified with hyperbranched ionic liquids (HBP-AMIM+PF6) as the reinforcing agent, high performance CFRPs were successfully prepared. The tensile strength, interfacial shear strength (IFSS) and interlaminar shear strength (ILSS) of the optimized formulation (HREP20/CF-HBPPF6) were 1016.1, 70.8 and 76.0 MPa, respectively. In addition, the CFRPs demonstrated excellent solvent and acid/alkali-resistance. The CFRPs could completely degrade within 24 h in DMSO at 140 °C, and the recycled CF still maintained the same tensile strength and ILSS as the original after multiple degradation cycles.

DOI: 10.1007/s10118-024-3191-8

Source: https://www.cjps.org/en/article/doi/10.1007/s10118-024-3191-8