Abstract

This paper describes how to measure THz spectrum of a filament shape sample without freeze-crushing chemical fiber. The filament yarn was installed in parallel on a stainless-steel O-ring. The fiber axis direction of this O-ring was installed in parallel to THz polarization direction. THz spectrum measured by this pre-treatment method was measured at a high S/N ratio than THz spectrum of the freeze-crushing sample. Next, THz spectra of drawn and undrawn fibers, which were confirmed to have different internal structure of the fibers by wide-angle X-ray images, were measured. THz spectra of these samples were measured with different yarn spacings and at different angles (at regular angle intervals of 30°) between the polarization direction of THz light and the fiber axis direction. When the fiber molecules were oriented along the axis by the drawing process, THz spectrum shape changed with the polarization angle, but it did not when the fiber orientations were random. This pre-treatment method avoids freeze-crushing, so the raw molecular structure inside the fiber was not altered thermally or mechanically and could be measured directly.

摘要

本文介绍了如何在不冷冻粉碎化纤的情况下测量长丝形状样品的太赫兹光谱。长丝纱线平行安装在不锈钢 O 形圈上。该 O 形环的光纤轴方向与太赫兹偏振方向平行。通过这种预处理方法测量的太赫兹光谱是在比冷冻破碎样品的太赫兹光谱高的信噪比下测量的。接下来，测量拉伸和未拉伸纤维的太赫兹光谱，这些纤维通过广角 X 射线图像确认具有不同的纤维内部结构。这些样品的太赫兹光谱是在不同的纱线间距和太赫兹光的偏振方向与光纤轴方向之间的不同角度（30°的规则角度间隔）下测量的。当纤维分子通过拉伸过程沿轴取向时，太赫兹光谱形状随偏振角而变化，但当纤维取向随机时，THz光谱形状不发生变化。这种预处理方法避免了冷冻破碎，因此纤维内部的原始分子结构不会受到热或机械的影响，可以直接测量。