富勒烯灰对聚乙二醇热分解和红外光谱的影响

Effects of Fullerene Soot on the Thermal Decomposition and Fourier Transform Infrared Spectrum of PEG

采用热分析和原位升温红外光谱实验研究了富勒烯灰(FS)对聚乙二醇(PEG)的影响。热分析结果显示,FS使得PEG的起始热分解温度和最大失重速率处的温度都明显推后。红外光谱结果证实,FS和PEG之间并没有生成新的化学键,FS也没有改变PEG分解产物的组成。通过对PEG和PEG+10%FS的凝聚相和气相升温红外光谱的检测,发现FS对PEG的凝聚相红外光谱影响并不明显,但却使得PEG分解放出气相产物的温度显著升高,说明FS对PEG热分解的抑制作用主要是通过对PEG气相产物的吸附和脱附来进行的。少量FS的加入即可显著抑制PEG的分解,使PEG的分解趋向高温。

Effects of fullerene soot（FS） on the thermal decomposition and Fourier transform infrared spectrum（FTIR） of polyethylene glycol（PEG,molecular weight=20 000） were investigated by thermal analysis（TG-DTG） and in-situ FTIR experiments.The results of thermal analytical experiments showed that the addition of FS postponed not only the initial decomposition temperatures but also the temperatures at maximum decomposition rate of PEG.The maximum decomposition peak temperatures increased and the maximum decomposition rates were lowered even with the addition of 0.1%FS.The in-situ FTIR experiments proved that there was no difference between the IR spectra of PEG and PEG with 10%FS.There wasn＇t any new chemical band formed but Vander waals force between FS and PEG.Although the addition of FS didn＇t influence the constitution of decomposition products of PEG,it obviously increased the decomposition temperature and the decomposition rate of PEG.Through the researches on condensed phase and gaseous phase FTIR spectrum of PEG and PEG with 10%FS,one could see that the effect of FS on the condensed phase FTIR spectrum of PEG was not obvious, but the addition of FS markedly enhanced the occurrence temperatures of most gaseous decomposition products of PEG.These results showed that the effect of FS on thermal decomposition of PEG was through the absorbance and desorption of gaseous phase decomposition products.With the temperature elevated,the gaseous products were gradually desorbed from the activity centers and the decomposition of PEG continued.The thermal decomposition peak of PEG was moved toward higher temperature with the addition of FS than that without FS.