再生碳纤维回收利用及其增材制造复合材料性能评价

为实现碳纤维增强树脂基复合材料废弃物高效、高质、环境友好型回收与再生碳纤维高值再利用，提出了热活化氧化物半导体回收碳纤维与再生碳纤维增强复合材料(rCFRP)增材再制造的工艺方法。通过电磁顺磁共振与红外光谱测试分析了回收原理，基于单因素实验研究了树脂基体分解率的影响因素以及显著因素对再生碳纤维结构、性能的作用规律，探究了再生碳纤维增强聚乳酸复合材料(rCF/PLA)的力学性能及其产品应用。结果表明，回收过程无液相产物，气相产物主要为CO₂、H₂O；树脂基体分解率与温度、时间呈正相关，O₂浓度及流量作用不显著，树脂基体分解率可达97.1%且再生碳纤维表面无积碳产生。再生碳纤维表面氧化与石墨结构刻蚀程度随温度升高而增加，在一定温度下，合理的处理时间可减小其表面氧化与石墨结构刻蚀程度。再生碳纤维的单丝拉伸性能与温度、时间呈正相关，其单丝拉伸性能可保持原碳纤维的99%以上。与聚乳酸相比，rCF/PLA的抗拉强度提高了7.47%，抗弯强度与模量分别提高了12.29%与52.4%；与原碳纤维增强聚乳酸复合材料相比，rCF/PLA的抗...

Recycling of Carbon Fiber and Performance Evaluation for Its Reinforced Composites Made of Additive Manufacturing

In order to realize the high-efficiency, high-quality and environment-friendly recycling of carbon fiber reinforced polymer waste and the high-value reuse of recycled carbon fiber, carbon fiber recycling by thermally activated of oxide semiconductors method and the additive remanufacturing process of recycled carbon fiber reinforced polymer(rCFRP) are proposed. The principle of recycling is analyzed by electron paramagnetic resonance and infrared spectroscopy. Based on complete randomized design, the factors affecting the decomposition rate of resin matrix and the effect of significant factors on the structure and mechanical properties of recycled carbon fiber are investigated. The mechanical properties of recycled carbon fiber reinforced polylactic acid composites (rCF/PLA) and their product applications are explored. The results show that there is no liquid phase product in the recycling process and the gas phase products are mainly CO₂ and H₂O.The resin matrix decomposition rate is positively correlated with temperature and time, and the O₂ concentration and that flow rate have no significant effect on the decomposition rate of resin matrix. The resin matrix decomposition rate can reach 97.1%, and no carbon deposits are produced on the surface of recycled carbon fiber. The increase of temperature will aggravate the degree of oxidation and graphite structure etching for recycled carbon fiber surface, while under certain temperature conditions, reasonable treatment time can reduce that. The monofilament tensile properties of recycled carbon fiber are positively correlated with temperature and time, and the monofilament tensile properties of recycled carbon fiber can maintain more than 99% of the original carbon fiber. Compared with polylactic acid, the tensile strength, flexural strength and modulus of rCF/PLA are respectively increased by 7.47%, 12.29% and 52.4%. Compared with the original carbon fiber reinforced polylactic acid composites, the tensile strength, flexural strength and modulus of rCF/PLA are respectively remained 95.1%, 96.23% and 103.25%. The products of additive remanufactured of rCFRP have good applications in sports, medical, automotive and other fields.