聚乙二醇中红外光谱研究

MIR SPECTROSCOPY STUDY OF POLYETHYLENE GLYCOL

采用MIR光谱研究了PEG的分子结构,研究发现:PEG的红外吸收模式主要包括:CH2不对称伸缩振动模式νasCH2-1-PEG、CH2对称伸缩振动模式νsCH2-PEG、CH2弯曲振动模式δCH2-PEG、CH2面外摇摆振动模式ωCH2-PEG、C—O伸缩振动模式νC—O-PEG和CH2面内摇摆振动模式ρCH2-PEG。进一步开展了PEG的TD-MIR光谱研究,PEG红外吸收模式增加了缔合羟基的伸缩振动模式νOH-PEG、C=O伸缩振动模式νC=O-PEG和缔合羟基的面外弯曲振动模式γOH-PEG。研究发现:随着测定温度的升高(303~523 K),PEG主要官能团对应的红外吸收频率及强度均有明显的改变,并进一步进行了机理研究。本项研究拓展了MIR光谱和TD-MIR光谱在重要的药剂辅料(PEG)结构及热稳定性方面的研究范围。

Molecular structure of the polyethylene glycol(PEG) was studied by mid-infrared(MIR) spectroscopy.The study results showed that the main infrared absorption mode of PEG included CH2 asymmetrical stretching vibration mode(νasCH2-1-PEG),CH2 symmetrical stretching vibration mode(νsCH2-PEG),CH2 bending vibration mode(δCH2-PEG),CH2 out of plane swing vibration mode(ωCH2-PEG),C—O stretching vibration mode(νC—O-PEG) and CH2 in plane rocking vibration mode(ρCH2-PEG).Temperature dependent mid-infrared( TD-MIR) spectroscopy of PEG was studied also,the infrared absorption mode of PEG was added by the following modes such as associated OH groups stretching vibration mode(νOH-PEG),C=O stretching vibration mode(νC=O-PEG) and associated OH groups out of plane bending vibration(γOH-PEG).In the test temperature range of 303 ~ 523 K,with the increase of temperature,the corresponding frequency and absorption intensity of the main functional groups in PEG were changed obviously,and the mechanism was further studied.The study in this paper expanded the research scope of MIR and TD-MIR spectroscopy in the analysis of structure and thermal stability of the important pharmaceutical excipients(PEG).