聚对苯二甲酸乙二醇酯C=O伸缩振动模式ATR二维相关红外光谱研究

Fourier Transform Attenuated Total Reflection Two-Dimensional Infrared Spectroscopy Study of Polyethylene Terephthalate C=O Stretch Vibration

采用变温傅里叶变换衰减全反射红外光谱技术(ATR-FTIR)结合二维相关红外光谱技术,分别研究了聚对苯二甲酸乙二醇酯(PET)的羰基红外伸缩振动模式(νC=O)。研究发现:玻璃转化温度(Tg)以下时,PET的νC=O的红外吸收频率包括1700cm^(-1)、1709cm^(-1)和1718cm^(-1),而随着测定温度的升高(313~343K),其红外吸收强度变化快慢顺序为:1709cm^(-1)>1700cm^(-1)>1718cm^(-1);而当在Tg以上时,PET的νC=O的红外吸收频率包括1709cm^(-1)和1718cm^(-1),而随着测定温度的升高(353~393K),PET的νC=O红外吸收强度变化快慢顺序为:1718cm^(-1)>1709cm^(-1)。本项研究拓展了ATR二维相关红外光谱技术在PET高分子材料热变性研究的范围。

The C= O stretch vibration （vc=o） of the polyethylene terephthalate （PET） had been studied by fourier transform attenuated total reflection infrared spectroscopy （ATR-FTIR） and ATR two-dimensional infrared spectroscopy. The vc-o occurred respectively near 1700 cm^-1 , 1709 cm^-1 and 1718 cm^-1 （below glass transition temperature） ,and the sequence of vc=o intensity changes was 1709 cm^-1〉 1700 cm^-1〉 1718 cm^-1 with the increase of temperature （313-343 K）. But the vc-o were observed near 1709 cm^-1 and 1718 cm^-1 （above glass transition temperature） ,and the sequence of vc-o intensity changes was 1718 cm^-1 〉1709 cm^-1 with the increase of temperature （353-393 K）. The paper demonstrated the key roles of ATR two-dimensional infrared spectroscopy in the analysis of thermal denaturation of the PET.