基于中红外光谱分析技术的凯夫拉纤维分子特性与热稳定性研究

Study on the Molecular Properties and Thermal Stability of Kevlar Fibers Based on Middle Infrared Spectroscopy Analytic Technology

采用中红外(MIR)光谱开展了凯夫拉纤维的分子结构研究。实验发现:凯夫拉纤维分子的红外吸收模式主要包括:ν_(NH-凯夫拉纤维)、ν_(amide-Ⅰ-凯夫拉纤维)、ν_(amide-Ⅱ-凯夫拉纤维)、ν_(C=C-凯夫拉纤维)、β_(C-H-凯夫拉纤维)和γ_(C-H-凯夫拉纤维)。进一步开展了凯夫拉纤维分子的四阶导数变温中红外(TD-MIR)光谱研究。实验发现:随着测定温度的升高(303 K~573 K),凯夫拉纤维分子主要官能团(νamide-Ⅱ-凯夫拉纤维-四阶导数)对应的红外吸收频率有一定的改变,凯夫拉纤维分子热稳定性进一步降低。本项研究拓展了MIR光谱和四阶导数TD-MIR光谱在重要的高分子材料(凯夫拉纤维)结构及热稳定性研究的范围。

The kevlar fibre molecular structure had been studied by middle infrared(MIR)spectroscopy.The infrared absorption modes of kevlar fibre molecular structure included ν_(NH-kevlar fibre),ν_(amide-Ⅰ-kevlar fibre),ν_(amide-Ⅱ-kevlar fibre),ν_(C=C-kevlar) fibre,β_(C-H-kevlar fibre) and γ_(C-H-kevlar fibre).The fourth derivative temperature-dependent middle infrared(TD-MIR)spectroscopy of kevlar fibre molecular were studied also in the temperature range of 303 K~573 K.With the increase of the temperature,the corresponding frequency of kevlar fibre molecular(νamide-Ⅱ-kevlar fibre-fourth derivative)had changed obviously,the thermal stability of kevlar decreased further and the mechanisation were researched also.The paper demonstrated the key roles of MIR spectroscopy and fourth derivative TD-MIR spectroscopy in the analysis of structure and thermal stability of the important polymers materials(kevlar fibre)