This study presents a closed-loop recycling process for carbon fibers using supercritical n-butanol. In the reclamation process, to achieve the highest composite recovery efficiency, the degradation of the carbon fiber-reinforced epoxy resin composites was conducted at various experimental feedstock ratios (ratio of composite waste to n-butanol), then the reclaimed carbon fiber (RCF) was characterized using various methods to develop an understanding of the changes in the properties and morphologies. In the remanufacturing process, in order to evaluate the reusability of the RCFs and the feasibility of the closed-loop recycling process for carbon fibers, the RCFs were mixed with new epoxy resin and polypropylene to remanufacture the composites, and then the mechanical properties of remanufacture composites were tested. The results show that, under an optimized process, the maximum recovery efficiency (feedstock ratio) of the composite was 0.1 g/ml. The impact of reclamation process on RCF lies in the degradation of tensile properties and the removal of sizing agent, which leads the change of the interfacial bonding strength between RCF and new resin, and eventually results in an impact on the performance of remanufacture composites. Compared with the virgin carbon fiber-reinforced composites, the improvement in the RCF-reinforced polypropylene properties and insubstantial variations in the tensile properties of the RCF validate the potential of the closed-loop recycling process for carbon fibers.

这项研究提出了一种使用超临界正丁醇的碳纤维闭环回收方法。在回收过程中，为了获得最高的复合材料回收效率，在各种实验原料比（复合废料与正丁醇之比）下对碳纤维增强环氧树脂复合材料进行降解，然后回收碳纤维（RCF）使用各种方法对特征进行了表征，以加深对特性和形态变化的理解。在再制造过程中，为了评估RCF的可重复使用性和闭环回收过程对碳纤维的可行性，将RCF与新的环氧树脂和聚丙烯混合以进行复合材料的再制造，然后再进行机械性能的再制造。复合材料进行了测试。结果表明，l。再生工艺对RCF的影响在于拉伸性能的下降和上浆剂的去除，这导致RCF与新树脂之间的界面粘合强度发生变化，最终对再制造复合材料的性能产生影响。与原始碳纤维增强复合材料相比，RCF增强聚丙烯性能的改善以及RCF拉伸性能的无实质变化证明了碳纤维闭环回收工艺的潜力。