Oxidation of unsaturated carboxylic acids under hydrothermal conditions.
Hydrothermal oxidation pathways of high molecular weight unsaturated carboxylic acids were investigated for the potential use of chemoselectivity to improve the efficiency of the desired products from biomasses directly containing or easily producing unsaturated carboxylic acids. Hock cleavage, which frequently occur at general chemical, was observed in the absence of any acid catalyst and may be a potential major oxidation cleavage mechanism, which leads to the cleavage at both the carbon-carbon double bond and the single bond near a double bond. The addition of a peroxyl radical to the double bond may be also a potential major oxidation mechanism, which leads to the oxidation cleavage mainly at the carbon-carbon double bond. Cleavage at the carbon-carbon bond near the double bond by the addition of a peroxyl radical to the double bond may also occur. However, oxidation at either alpha-, beta-, or gamma-carbon to the -COOH group hardly occurred. These results may help to selectively produce desired products from biomasses, such as lignin and oils.
Jin
Fangming
F
State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, China. fmjin@tongji.edu.cn
Zhong
Heng
H
Cao
Jianglin
J
Cao
Jianxun
J
Kawasaki
Kohei
K
Kishita
Astushi
A
Matsumoto
Takatoshi
T
Tohji
Kazuyuki
K
Enomoto
Heiji
H
D002264:Carboxylic Acids / Q000737:chemistry*; D004951:Esterification; D008401:Gas Chromatography-Mass Spectrometry; D006586:Hexanes / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry; D017665:Hydroxyl Radical / Q000737:chemistry; D008970:Molecular Weight; D019301:Oleic Acid / Q000737:chemistry*; D010084:Oxidation-Reduction; D010545:Peroxides / Q000737:chemistry; D013696:Temperature; D014867:Water / Q000737:chemistry*
D002264:Carboxylic Acids; D006586:Hexanes; D010545:Peroxides; D014867:Water; C026385:n-hexane; D019301:Oleic Acid; C049375:perhydroxyl radical; D017665:Hydroxyl Radical; D006859:Hydrogen