Ultra-thin electrospun nanofibers for development of damage-tolerant composite laminates
Ultra-thin electrospun nanofibers for development of damage-tolerant composite laminates
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DOI：
10.1016/j.mtchem.2019.100202
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发表时间：
2019-12-01
影响因子：
7.3
通讯作者：
Nezhad, H. Yazdani
中科院分区：
文献类型：
--
作者：
An, D.;Lotfian, S.;Nezhad, H. Yazdani
本文通过开发和嵌入由聚酰胺6.6制成的高度拉伸的超薄电纺热塑性纳米纤维，克服了新型多功能纤维增强聚合物复合材料层间增韧的现有挑战。纳米纤维通过确保整个层片的平滑应力传递并用于在所需方向上定制机械性能而不干扰几何特征，厚1.5 g/m2静电纺丝纳米纤维的研究结果表明，在试样上，峰值载荷和裂纹张开位移分别提高了85%和43%，在起始和扩展阶段都有显著提高（>25%），并且没有牺牲断裂韧性。改进后的试件初始刚度提高了近150%。这种增强主要是由于纳米纤维有助于在邻近聚四氟乙烯（PTFE）膜的裂纹尖端处的富含树脂的区域的刚度。用纳米纤维（每层具有2.0 gsm的平均厚度）改性的玻璃纤维增强的机织酚醛预浸渍复合材料层片降低了玻璃纤维和酚醛基质之间的粘合性能（化学结合）。纳米纤维的密度增加，在层片之间形成物理屏障的可能性也增加，导致树脂流动损失和粘合性差。这种效果是显而易见的，从微观调查和减少断裂韧性数据在开始和扩展阶段。(C)2019爱思唯尔有限公司版权所有。
The present article overcomes existing challenges in inter-laminar toughening of novel multifunctional fiber-reinforced polymer composites via development and embedment of highly stretched, ultra-thin electrospun thermoplastic nanofibers made of polyamide 6.6. The nanofibers exhibit significant enhancement of the composite laminate's structural integrity with almost zero weight penalty via ensuring a smooth stress transfer throughout the plies and serving tailoring mechanical properties in desired directions, with no interference with geometric features, e.g., thickness. The findings for 1.5 g per square meter electrospun nanofibers have demonstrated, on test coupon specimens, improvements up to 85% and 43% in peak load and crack opening displacement, respectively, with significant improvement (>25%) and no sacrifice of fracture toughness at both initiation and propagation phases. The initial stiffness for the modified specimens was improved by nearly 150%. The enhancement is mainly due to nanofibers contributing to the stiffness of the resin-rich area at the crack tip adjacent to the polytetrafluoroethylene (PTFE) film. Glass fiber-reinforced woven phenolic pre-impregnated composite plies have been modified with the nanofibers (each layer having an average thickness of 2.0 gsm) degrades the adhesion properties (chemical bonding) between glass fibers and the phenolic matrix. The density of nanofibers increases, so does the likelihood of forming a physical barrier between the plies resulting in the loss of resin flow and poor adhesion. Such an effect was evident from microscopic investigations and reduction in fracture toughness data at the initiation and propagation phases. (C) 2019 Elsevier Ltd. All rights reserved.