Foundation Of Research Of Synthesis Of Epoxidized Soybean Oil In Liquid Phase Without Carboxylic Acid

Epoxidized soybean oil (ESO) was prepared without solvent or sulfuric acid. Some factors affecting the epoxy value of product were investigated, including the type of carboxylic acid, amount and concentration of hydrogen peroxide, etc. . The synthesis process was optimized by orthogonal experiment, that is, soybean oil : formic acid : hydrogen peroxide of 30% concentration (mass) = 1 : 0.15 : 1.0, with reaction temperature of 60°C and reaction time of 5h - 6 h. The epoxy value is above 6.20% and residual iodine value is below 6.0%. The craftwork of epoxidation was applied to produce ESO in a reation kettle with a volume of 8 m3 to get production quality up to or exceed the industry standard.ESO was also prepared with homemade phase transfer catalyst oxodiperoxotungsto phosphate Q3{PO4[WO(O2)2]4} in the absence of sulfuric acid, carboxylic acid and solvent. The product was characterized by FT-IR, nuclear magnetic resonance spectroscopy, X-ray diffraction, thermogravimetry. As a result, the ethylenic linkage in soybean oil changed into epoxy group after phase transfer reaction. And ESO was obtained.Phase transfer mechanism with Q3{PO4[WO(O2)2]4} as catalyst is preliminary investigated. The principal factor effects catalytic reaction of Q3{PO4[WO(O2)2]4} is the rigidity and lipophilicity of cation, comparing differences amongst five kinds of homemade catalyst during epoxidation. Some factors influence epoxidation were investigated by comparing. They are: quaternary ammonium cation, reaction temperature and time, drop speed of hydrogen peroxide aqueous solution. The ethylenic linkage conversion and selectivity for oxide can be increased to get high quality of ESO by prolonging the reaction, slowing down drop speed of H2O2 or using light concentration H2O2, as was analysed. The best epoxy value during experiment is 6.28% and 6.26% respectively.Compared with Halcon traditional method, phase transfer catalysis method with Q3{PO4[WO(O2)2]4} has some advantages as follows. It is not only safe for operation but also the cause of reduction of the discharge of acid waste water, because carboxylic acid and protonic acid, for example sulfuric acid has not been used. Epoxidation catalysed by Q3{PO4[WO(O2)2]4} is a mild, quick and efficiency reaction, and H2O2 also has a high utilization ratio. There is no liquid pollution according to the method because a little bit remained H2O2 breaks down into water. Selectivity for oxide is quite high because of the absence of carboxylic acid which may lead to ring open reaction. In addition to these, solvent-free system is friendly to environment.