多元醇酯冷冻机油的化学组成及其分子结构鉴定

Analysis of a POE Refrigeration Oil for Its Chemical Composition and Molecular Structures

应用傅里叶变换红外光谱法(FTIR)和气相色谱-质谱法(GC-MS)对某品牌进口多元醇酯(POE)冷冻机油(简称A油)的化学组成和结构进行剖析。FTIR光谱图显示A油为季戊四醇脂肪酸酯,且表明其酯化完全。从GC-MS的总离子流色谱图可推断A油有5种主要组成;从A油经甲酯化后的GC-MS谱图可推断A油系季戊四醇与辛酸和壬酸酯化反应的产物。如酯化反应达到完全,则能产生6种产物,由于其中2种产物为同分异构体,因此在图谱中只出现5个信号峰。在实验室中用季戊四醇和壬酸模拟A油的合成,经分析所得产物,证实了对A油组成的推断。

FTIR and GC-MS in hyphenation were applied to the analysis of an imported POE refrigeration oil(abbr.as oil A)for its chemical composition and molecular structures of the constituents.As shown by the FTIR spectrum,oil A is an ester of pentaerythritol and acyclic carboxylic acid with complete esterification.It was found in the TIC chromatogram of GC-MS,that there are 5main components in the oil.By applying the ester exchange technique,pentaerythritol was replaced by methyl alcohol.It was deduced from the GC-MS spectra obtained after trans-esterification that oil A is the product of esterification of pentaerythritol with ethylhexanoic acid and azelaic acid.Under complete esterification,6products will be produced,among which 2products are isomers.This is the reason that only 5signal peaks were found in the chromatogram.The above result was verified by synthesis of a simulated oil A through esterification of pentaerythritol with azelaic acid in laboratory.