Shaker A, Khedewy Amira T, Hassan Mohamed A, El-Baky Marwa A Abd
Mechanical Design and Production Engineering Department, Zagazig University, Zagazig, 44519, Egypt.
Sci Rep. 2023 Oct 13;13(1):17368. doi: 10.1038/s41598-023-44020-x.
Creating ultrathin, mountable fibers from a wide range of polymeric functional materials has made electrospinning an adequate approach to producing highly flexible and elastic materials. In this paper, electrospinning was utilized to produce thermoplastic polyurethane (TPU) nanofibrous membranes for the purpose of studying their thermal and mechanical properties. Towards a study of the effects of fiber orientation and multi-walled carbon nanotubes (MWCNTs) as a filler on both mechanical and thermal characteristics of electrospun TPU mats, an experimental comparison was held between unidirectional and randomly aligned TPU and TPU/MWCNTs nanofibrous structures. The incorporation of MWCNTs into randomly oriented TPU nanofibers resulted in a significant increase in Young's modulus (E), from 3.9 to 7.5 MPa. On the other hand, for unidirectionally spun fibers, Young's modulus increased from 17.1 to 18.4 MPa upon the addition of MWCNTs. However, dynamic mechanical analysis revealed a different behavior. The randomly oriented specimens exhibited a storage modulus with a significant increase from 180 to 614 MPa for TPU and TPU/MWCNTs mats, respectively, and a slight increase from 119 to 143 MPa for unidirectional TPU and TPU/MWCNTs mats, respectively. Meanwhile, the loss modulus increased with the addition of MWCNTs from 15.7 to 58.9 MPa and from 6.4 to 12 MPa for the random and aligned fibers, respectively. The glass transition values for all the mats fell in the temperature range of - 60 to - 20 °C. The thermal degradation of the membranes was not significantly affected by the addition of MWCNTs, indicating that the mixing of the two constituents did not change the TPU's polymer structure and that the TPU/MWCNTs nanocomposite exhibited stable thermal degradation properties.
利用多种聚合功能材料制造超薄、可装配的纤维，使静电纺丝成为生产高柔韧性和弹性材料的一种合适方法。本文利用静电纺丝制备热塑性聚氨酯（TPU）纳米纤维膜，以研究其热性能和力学性能。为了研究纤维取向和作为填料的多壁碳纳米管（MWCNT）对静电纺TPU垫的力学和热性能的影响，对单向排列和随机排列的TPU以及TPU/MWCNT纳米纤维结构进行了实验比较。将MWCNT掺入随机取向的TPU纳米纤维中，导致杨氏模量（E）显著增加，从3.9MPa增至7.5MPa。另一方面，对于单向纺丝纤维，添加MWCNT后杨氏模量从17.1MPa增加到18.4MPa。然而，动态力学分析显示出不同的行为。随机取向的样品表现出储能模量显著增加，TPU和TPU/MWCNT垫分别从180MPa增至614MPa，单向TPU和TPU/MWCNT垫分别从119MPa略有增至143MPa。同时，损耗模量随着MWCNT的添加而增加，随机纤维和取向纤维分别从15.7MPa增至58.9MPa以及从6.4MPa增至12MPa。所有垫子的玻璃化转变值都落在-60至-20℃的温度范围内。MWCNT的添加对膜的热降解没有显著影响，这表明两种成分的混合没有改变TPU的聚合物结构，并且TPU/MWCNT纳米复合材料表现出稳定的热降解性能。
