可口可乐内膜的结构及热稳定性研究

Structure and Thermal Stability Study of Coca-Cola Intima

采用变温傅里叶变换衰减全反射红外光谱(ATR-FTIR)技术研究了可口可乐内膜的的结构及热稳定性.通过研究可口可乐内膜的一维变温红外光谱和二阶导数变温红外光谱发现:可口可乐内膜主要存在着羟基伸缩振动模式(νOH)、CH3不对称伸缩振动模式(νas CH3)、C=O伸缩振动模式(νC=O)、骨架振动模式(νC—C)、CH2左右式弯曲振动模式(δCH2)、O—CH2中亚甲基弯曲振动模式(δO—CH2)、CH3耦合振动模式(νCH3—CH3)、Ar—O—R不对称伸缩振动模式(νas Ar-O-R)、端环氧基的伸缩振动模式(νepoxy-group)和C—H面外弯曲振动模式(γC—H).最终确定可口可乐内膜主要包含着环氧树脂—酯结构和少量环氧树脂结构.采用变温ATR-FTIR技术(303~393 K)进一步开展了可口可乐内膜热稳定性研究.拓展了变温ATR-FTIR技术在环氧树脂类涂料的结构及热稳定性方面的研究范围.

The Coca-Cola intima structure and thermal stability are characterized by attenuated total reflection fourier transform infrared spectroscopy （ATR-FTIR）. The one-dimensional variable temperature infrared spectroscopy and second derivative variable temperature infrared spectroscopy of Coca-Cola intima are studied also. There are hydroxy stretch vibration （VOH）, CH3 asymmetrical stretch vibration （VasCH3）, C=O stretch vibration （Vc=0）, C-C stretch vibration （Vc-c）, CH2 scissoring bond vibration （δCH2）, O-CH2 scissoring bond vibration （δo-CH2）, CH3 coupled vibration （vCH3-CH3）, Ar-O-R asymmetrical stretch vibration （VasAr-O-R）, epoxy-terminated stretch vibration （Vepoxy-group） and C--H out-of-plane bending vibration （γc-H）- There are structure of epoxy resin and structure of epoxy resin- ester. In the temperature range 303-393 K, the Coca-Cola intima thermal stability is studied also. The study demonstrates the key roles of variable temperature ATR-FTIR in the analysis of structure and thermal stability of the epoxy resin coating.