Ma Yingjian, Zhuang Yangpeng, Li Chunwei, Luo Chuyang, Shen Xing
State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
Shanghai High Performance Fibers and Composites Center (Province-Ministry Joint), Center for Civil Aviation Composites, Donghua University, Shanghai 201620, China.
Polymers (Basel). 2022 Mar 26;14(7):1348. doi: 10.3390/polym14071348.
This work concentrated on the interlaminar mechanical properties and toughening mechanism of carbon fiber-reinforced bismaleimide resin (CF/BMI) composites modified by polyacrylonitrile (PAN) nanofiber films. The PAN nanofiber films were prepared by electrospinning. End-notched flexure (ENF) and short-beam strength tests were conducted to assess the mode II fracture toughness (G) and interlaminar shear strength (ILSS). The results showed that the G and ILSS of PAN-modified specimens are 1900.4 J/m and 93.1 MPa, which was 21.4% and 5.4% higher than that of the virgin specimens (1565.5 J/m and 88.3 MPa), respectively. The scanning electron microscopy (SEM) images of the fracture surface revealed that the PAN nanofiber films toughen the composite on two scales. On the mesoscopic scale, the composite laminates modified by PAN formed a resin-rich layer with high strength and toughness, which made the crack propagate across the layers. At the microscopic scale, the crack propagation between two-dimensional nanofiber films led to constant pull-out and breakage of the nanofibers. As a result, the interlaminar fracture toughness of the composite laminates improved.
这项工作集中研究了由聚丙烯腈（PAN）纳米纤维膜改性的碳纤维增强双马来酰亚胺树脂（CF/BMI）复合材料的层间力学性能和增韧机理。通过静电纺丝制备了PAN纳米纤维膜。进行了端部切口弯曲（ENF）和短梁强度测试，以评估II型断裂韧性（G）和层间剪切强度（ILSS）。结果表明，PAN改性试样的G和ILSS分别为1900.4 J/m和93.1 MPa，分别比原始试样（1565.5 J/m和88.3 MPa）高21.4%和5.4%。断口表面的扫描电子显微镜（SEM）图像显示，PAN纳米纤维膜在两个尺度上使复合材料增韧。在细观尺度上，由PAN改性的复合层压板形成了具有高强度和韧性的富树脂层，这使得裂纹跨层扩展。在微观尺度上，二维纳米纤维膜之间的裂纹扩展导致纳米纤维不断拔出和断裂。结果，复合层压板的层间断裂韧性得到了提高。
