反式茴脑低温氧气氧化性质及其产物研究

Oxidation Characteristics and Products of trans-Anethole with Oxygen at Low Temperature

摘要:

本文进行了低温下反式茴脑与氧气的氧化反应研究，采用自行设计的小型密闭压力容器实验装置跟踪反应压力变化，考察了反式茴脑氧化反应特性，利用碘量法分析了过氧化物浓度，利用气相色谱-质谱联用仪分析了反应产物种类。实验结果表明，压力变化显示反式茴脑氧化过程分三个阶段，首先是缓慢吸收氧气，然后是显著的快速氧化反应，最后是氧化趋于结束阶段。反式茴脑吸收氧气生成过氧化物，过氧化物生成量受反应条件影响，当反应温度95℃，反应时间4h时，过氧化值最大为85.07 mmol/kg；反式茴脑氧化反应产物比较复杂，最主要的产物有茴香醛、乙醛、茴香环氧化物、茴香二醇、茴香偶酰等，当反应温度为55℃时，茴香醛选择性达到70.36%。

Abstract:

Oxidation reaction of trans-anethole with oxygen was investigated at low temperature. The oxidation characteristic and pressure of trans-anethole were determined using a self-designed mini closed pressure vessel device. Peroxide concentration was measured by iodimetry, and constituents of oxidation products was detected by gas chromatography-mass spectrometry (GC-MS). Results showed that trans-anethole oxidation occurred in three stages: first, oxygen was absorbed slowly, then trans-anethole oxidation reaction became rapid, finally, oxidation process went to end. Trans-anethole absorbed oxygen，followed by the generation of anethole peroxide. Peroxide concentration was influenced by reaction condition, and peroxide concentration reached the maximum (85.07 mmol/kg) at 95℃ 4h. The oxidation products were complex, including anisaldehyde, acetaldehyde, anethole epoxide, anethole diol and P-anisil, and the selectivity of anisaldehyde is 70.36% at 55℃.