Structural studies of electrospun nylon 6 fibers from solution and melt
Structural studies of electrospun nylon 6 fibers from solution and melt
复制标题
DOI：
10.1016/j.polymer.2011.07.038
复制
发表时间：
2011-09-12
期刊：
影响因子：
4.6
通讯作者：
Joo, Yong Lak
中科院分区：
文献类型：
--
作者：
Cho, Daehwan;Zhmayev, Eduard;Joo, Yong Lak
用两种不同的静电纺丝方法制备了尼龙6(N6)纤维，一种是在室温下由N6和甲酸溶液制备的，另一种是在高温下由N6熔体制备的。用多种方法研究了溶液和熔体电纺N6纤维的晶体结构，以及退火对结构的影响。不同升温速率下的差示扫描量热仪(DSC)、变温X射线衍射仪(XRD)和傅立叶变换红外光谱(FTIR)的联合分析表明，熔融N6纤维主要表现出亚稳定的伽马晶型和低分子取向，而溶液电纺纤维则表现出α和伽马晶型和较高的分子取向度。在较高的退火温度下，熔体电纺纤维中亚稳定的伽马晶体容易转变为热力学稳定的α-晶型晶体，而溶液电纺纤维中的晶体具有较高的热稳定性。非等温模拟和喷射温度的现场测量表明，喷射附近的电流体驱动气流的强化换热导致快速淬火，这是熔体电纺纤维中较不稳定的伽马晶体和较低的分子取向度的原因。(C)2011爱思唯尔有限公司。保留所有权利。
Nylon 6 (N6) fibers have been fabricated via two different electrospinning schemes, from solution of N6 and formic acid at room temperature as well as from N6 melt at elevated temperature. The crystal structures of electrospun N6 fibers from solution and melt, and the annealing effect on the structures were studied by using various techniques. Combined analysis of the differential scanning calorimetry (DSC) at various heating rates, temperature-dependent X-ray diffraction (XRD), and Fourier-transform infrared (FTIR) spectroscopy indicates that N6 fibers from melt predominantly exhibit the meta-stable gamma-crystalline forms and low molecular orientation, while solution electrospun fibers from slowly evaporating solvent show both alpha- and gamma-form crystals and higher degree of molecular orientation. At high annealing temperature, the meta-stable gamma-crystals in melt electrospun fibers easily transform into thermodynamically stable a-form crystals, while crystals in solution electrospun fibers exhibit higher thermal stability. Nonisothermal modeling and in-situ measurements of jet temperature indicate that rapid quenching due to enhanced heat transfer by electrohydrodynamically driven air flow near the jet is responsible for the less stable gamma-crystals and lower degree of molecular orientation in melt electrospun fibers. (C) 2011 Elsevier Ltd. All rights reserved.