太赫兹光谱检测热塑性聚氨酯弹性体的热稳定性

Thermal stability of thermoplastic polyurethane elastomer detected by terahertz spectroscopy

摘要:

热稳定性是高分子材料的一个关键指标，利用太赫兹时域光谱(THz-TDS)技术结合控温装置，检测了两种热塑性聚氨酯弹性体(TPU)固体样本。室温条件下，不同类型TPU的太赫兹吸收系数及折射率数值存在差异。在从20 ℃加热至160 ℃过程中，随着温度的升高，太赫兹吸收系数逐渐增加，而折射率随之降低。其线性拟合转折点与已报道的材料维卡转换温度基本对应，并且热稳定性较高的样品，升降温后光学常数相对保持更稳定。研究结果表明太赫兹光谱技术可为检测高分子材料热稳定性提供新的途径。

Abstract:

Thermal stability is a key indicator for polymeric materials. Using Terahertz Time-Domain Spectroscopy(THz-TDS) technology combined with a temperature control device, two types of thermoplastic polyurethane elastomers(TPU) solid samples are tested. At room temperature, there are differences in the terahertz absorption coefficients and refractive index values of different types of TPU. During the process of heating from 20 ℃ to 160 ℃, as the temperature increases, the terahertz absorption coefficient gradually increases, while the refractive index decreases. The turning point of the linear fit corresponds to the reported Vicat transition temperature of the material, and the sample with higher thermal stability maintains its optical constants more stable after heating and cooling. The research results indicate that terahertz spectroscopy technology can provide a new approach for detecting the thermal stability of polymeric materials.