在303~393 K 的温度范围内,分别测定聚四氟乙烯 F-C-F 弯曲振动模式(δ_CF2(PTFE))的一维红外光谱、二阶导数红外光谱、四阶导数红外光谱和去卷积红外光谱。研究发现:640 和 620 cm^-1 附近的吸收峰归属于 F-C-F 面外摇摆振动模式(ω_CF2-A 和 ω_CF2-B),550 cm^-1 附近的吸收峰归属于 F-C-F 剪式振动模式(δ_CF2),而 500 cm^-1 附近的吸收峰则归属于 F-C-F 面内摇摆振动模式(ρ_CF2)。最后研究了聚四氟乙烯二维红外光谱。研究发现:随着测定温度的升高,δ_CF2(PTFE)吸收强度变化快慢的顺序为:550 cm^-1(δ_CF2)> 500 cm^-1(ρ_CF2)> 620 cm^-1(ω_CF2-B)> 640 cm^-1(ω_CF2-A)。本项研究拓展了二维红外光谱技术在聚四氟乙烯材料热变性的方面的研究范围。

The temperature effect of the F-C-F bending vibration mode of polytetrafluoroethene had been studied by one-dimensional infrared spectroscopy,second derivative infrared spectroscopy,fourth derivative infrared spectroscopy and deconvolution infrared spectroscopy in the temperature range from 303 K to 393 K.The polytetrafluoroethene F-C-F wagging vibration mode(ω_CF2-A and ω_CF2-B)occurred respectively near 640 cm^-1 and 620 cm^-1.The band resulting from the scissoring vibration mode(δ_CF2)appeared near 550 cm^-1,but the band resulting from the rocking vibration mode(ρ_CF2)appeared near 500 cm^-1.Two-dimensional infrared spectroscopy of polytetrafluoroethene were studied to determine the sequence of F-C-F bending vibration mode intensity changes.The relative sequence of intensity changes was given by 550 cm^-1(δ_CF2)> 500 cm^-1(ρ_CF2)> 620 cm^-1(ω_CF2)> 640 cm^-1(ω_CF2).The study demonstrated the key roles of two-dimensional infrared spectroscopy in the analysis of thermal denaturation of the polytetrafluoroethene.