FENG Shu-bo　YANG Hua ZHENG Er-li ZHANG Lin FAN Ming

(College of Chemical and Pharmaceutical Engineering, Hebei University of Science and Technology, Shijiazhuang, 050018)

Abstract: A heteropolyphosphatotungstate for the epoxidation of fatty acid methyl esters was prepared using sodium tungstate, phosphoric acid,hydrogen peroxide and cetyl pyridinium chloride. It was found that catalysts prepared by dissolving cetyl pyridinium chloride with ethyl acetate aggregate between the interface of organic phase and water phase. The catalyst was separated by simple filtration. The action of the title catalyst with H₂O₂ leads to a formation of homogeneous phase and an accelerated reaction rate. The catalyst will precipitate in solid particles with the consumption of H₂O₂ and the decreasing temperature, its recovery is up to 90% and catalytic activity is almost unchanged after six consecutive uses. The catalyst structures before and after epoxidation reaction were characterized by FT-IR. The effect of reaction conditions on the epoxidation and H₂O₂ utilization was investigated. Under the conditions of reaction time 2.5h, catalyst 0.3g, stepwise addition of 30wt% H₂O₂ 3.5g(30.88mmol), reaction temperature 65℃, 1,2-dichloroethane 20mL, FAMEs 5.0g(22.84mmol double bond), the product epoxy value is up to 5.78%, double bond epoxidation selectivity 81.9% and H₂O₂ utilization 86%.

Keywords: fatty acid methyl ester, epoxidation, phase-transfer catalyst, hydrogen peroxide, phosphotungstic acid, plastizer

E-mail:  fengsb@263.net

Journal of Molecular Catalysis, Vol. 24, Issue 3, 2010, 222-227