Synthesis Of Epoxidized Soybean Oil Under Carboxylic Acid-Free Condition

Epoxidized soybean oil (ESBO) has been used for many commercial applications, e.g. as plasticizers and stabilizers in chlorine containing resins, as additives in lubricants, as components in thermosetting plastics and so on. It shows excellent promise as inexpensive renewable materials for industrial application. Compared with the main plasticizer dioctylphthalate in the market nowadays, it is not toxic and has good stability to light and heat. It can be used to synthesize the packing materials for food and medicine. With unceasingly rise in prices of petrochemicals, which are drying up day by day, it is especially important to research and develop ESBO.In the first part, the actuality of the synthesis of ESBO at present is summarized. The current method to produce ESBO is epoxidation of soybean oil (SBO) with peroxy-carboxylic acids catalyzed by acidic catalysts. However, the peroxy-carboxylic acids are harmful to our human beings and not stable, which can easily decompose when heated. Moreover, the acidic catalysts may damage the experimental instruments and cause the worse quality of the product. Thus, our research focus on how to avoid the problem caused by using peroxy-carboxylic acids and to make the epoxidation technique cleaner.The recent development on the epoxidation of alkenes using hydrogen peroxide as oxidant in different catalytic systems is also reviewed in this part. Several important kinds of catalysts are discussed, such as methyltrioxorhenium, metal porphyrins, tungsten-based compounds and so on. The yields and selectivities in different catalytic systems are summarized, and the advantages and disadvantages of them are evaluated as well.Considering the advantages and disadvantages of different catalytic systems, the practicability of synthetic method in industry, as well as some important efforts in green oxidation achieved in our laboratory, in this thesis, ESBO is synthesized by hydrogen peroxide under carboxylic acid-free condition using tungsten-based compounds as catalysts.In the second part, a series of tungsten-based catalysts were synthesized and used in the epoxidation of SBO. The chemical structure of the synthesized ESBO was characterized by ]H NMR, I3C NMR and FT-IR spectroscopy. Furthermore, the acid value, epoxy value and iodine value were examined according to the China National Standard. The effects of catalysts, reaction time, temperature, pH and solvents on the epoxidation were also discussed. The experimental results showed that ESBO could be successfully synthesized. The optimum reaction condition was achieved using WO427PO437 CH3(C8H17)3NHSO4 as catalyst and ethyl acetate as solvent at 60 °C for 7 h, with a high epoxy value of 6.28%.In the third part, a new type of catalyst was synthesized by modifying silica gel with ionic liquid and active W species. The layer number of ionic liquid was increased to improve the amount of the active species. In order to optimize the reaction condition, L9(33) orthogonal experiment was carried out. The separation of final products and recovery of catalysts were easier when the catalyst was supported on the silica gel. However, the catalytic activity of the catalysts decreased and the epoxy value of the product required improving.