医用白凡士林三级MIR光谱研究

Study on the Three-Step MIR Spectroscopy of Medical Vaseline

采用中红外(MIR)光谱研究医用白凡士林(简称:白凡士林)的分子结构.研究发现:白凡士林的红外吸收模式主要包括:CH3不对称伸缩振动模式(vas CH3-白凡士林)、CH3对称伸缩振动模式(vs CH3-白凡士林)、CH2不对称伸缩振动模式(vas CH2-白凡士林)、CH2对称伸缩振动模式(vs CH2-白凡士林)、CH3不对称变角振动模式(δas CH3-白凡士林)、CH2对称变角振动模式(δs CH3-白凡士林)、CH2变角振动模式(δCH2-白凡士林)和CH2面内摇摆振动模式(γCH2-白凡士林).进一步开展了白凡士林的变温中红外(TD-MIR)光谱研究.研究发现:随着测定温度的升高(293~433 K),白凡士林主要官能团对应的红外吸收频率及强度均有所改变.最后采用二维中红外(2D-MIR)光谱进一步开展白凡士林热稳定性的研究.拓展了三级MIR光谱在重要的精细石油化工产品(白凡士林)结构及热稳定性上的研究范围.

The medical vaseline(short for vaseline)molecular structure had been studied by infrared(MIR)spectroscopy.There were CH3 asymmetrical stretching vibration mode(vas CH3-vaseline),CH3 symmetrical stretching vibration mode(vs CH3-vaseline),CH2 asymmetrical stretching vibration mode(vas CH2-vaseline),CH2 symmetrical stretching vibration mode(vs CH2-vaseline),CH3 asymmetrical bending stretching vibration mode(δas CH3-vaseline),CH3 symmetrical bending vibration mode(δs CH3-vaseline),CH2 bending vibration mode(δCH2-vaseline)and CH2 rocking vibration mode(γCH2-vaseline).Temperature-dependent infrared(TD-MIR)spectroscopy of vaseline were studied also in the temperature range 293~433 K.With the increase of the temperature,the corresponding frequency and absorption intensity of vaseline had changed obviously.The thermal stability of vaseline were considered by the two dimensional infrared(2D-MIR)spectroscopy also.The paper demonstrated the key roles of three-step MIR spectroscopy in the analysis of molecular structure and thermal stability of the important fine petrochemical products(vaseline).