Constructing a weaving structure for aramid fiber by carbon nanotube-based network to simultaneously improve composites interfacial properties and compressive properties

Abstract Compared with carbon fiber, aramid fiber exhibits weak performance in its transverse direction, and it is the bottleneck problem for its further application. To address the problem, a new weaving strategy is proposed by incorporating carbon nanotube (CNT)-based network inside bulk fiber to bundle the extended macromolecules together. Firstly, this unique three dimensional CNT-based network (CNT-NT) was synthesized and incorporated into bulk fiber by solution blending. Then, the influences of CNT-NT on fibers' axial and transverse performance are evaluated. The results of macromolecules' axial orientation suggest that the macromolecules could easily penetrate into this three dimensional network (CNT-NT), forming a weaving structure, and this further hinders the movement of macromolecules and decrease its orientation in axial direction. More importantly, fiber transverse performance is greatly improved by this weaving structure, mainly due to (1) the improvement of skin/core connection and (2) the restraining of nanofibrils' relative sliding. It is found that the composites interfacial failure mode changes from fiber's skin/core destruction to fiber/resin debonding, and the composite interfacial properties and fiber’ compressive strength are correspondingly increased by 131% and 82%. Unlike traditional “increasing the macromolecules interaction” strategy, it is believed this new weaving strategy integrates the advantage of easy production, cost-effective as well as simultaneously improving fiber's composite interfacial properties and compressive strength, and can be employed as valuable guidance for the design and manufacture of other high performance organic fibers.