Study On Epoxidation Reaction Of Synthesis Of Styrene Oxide Catalyzed By Molybdenum Compound

Styrene oxide is an important chemical material used over a wide range of field, for example, as a main material in the preparation of perfumes and medicament, a stabilizer for polymers, an ultraviolet ray absorber, sweetening materials etc. However, because the tradition synthesis method of styrene oxide is difficult, low yield, high cost and its output can not meet the needs of the developing market. the new methods to solve the problems have recently been focused on. Two catalytic reaction systems to synthesize styrene oxide from styrene were researched in this paper. In the systems, molybdenum compound (ammonium molybdate and molybdenum blue) were used as catalysts, hydrogen peroxide was used as oxidant, di-n-octyltin oxide as phase transfer reagent and chloroform as solvent.In the ammonium molybdate-di-n-octyltin oxide system, the effect of the amount of catalyst, oxidant, solvent, phase transfer and the reaction time on the synthetic reaction of styrene oxide were researched at ordinary temperature and pressure. The experimental results indicate that the highest yield of styrene oxide could reach 49.16% under which the amount of oxidant, phase transfer and catalyst were respectively 31.16%,11.20%,2.64% relative to the amount of styrene. The reaction time of reaching the highest yield was about 24 hours in different experimental conditions. The effect of the amount of solvent was not distinct. In the molybdenum blue- di-n-octyltin oxide system, besides the effect of the amount of catalyst, oxidant, phase transfer, solvent and the reaction time, the effect of reaction temperature on the synthetic reaction of styrene oxide was researched. The results show that the highest yield of styrene oxide could reach 68.29% of which was higher than that in the ammonium molybdate - di-n-octyltin oxide system. The effect of the amount of solvent was not distinct too. The time of reaching the highest yield was about 28 hours, which was longer than that in the ammonium molybdate - di-n-octyltin oxide system. In this system trimethylamine was used as a trigger. Under the highest yield of styrene oxide, the amount of oxidant, phase transfer and catalyst were respectively 31.16%,8.96%,1.15%relative to the amount of styrene. With the experimental data, the reaction dynamics of the system was studied. The macro dynamics equation can be described as in which the reaction progression is n= 2 and velocity constant ish-1mol-1. The reactionactivation energy Ea=165.08 kJ/mol.In order to enhance the used ratio of materials, the unreacted substances in the reacted mixture were separated and recovered. The experiment results show that the recovery of di-n-octyltin oxide was 63%, of chloroform was 80% and of styrene was 50%. It can obtain the same results to use the recovered materials into the reaction system...