A Research Of Compound Solid Superacid Catalyst In The Esterification Reaction

This article is about the synthesis of SO42-/ZrO2-TiO2solid superacid catalyst. And the SO42-ZrO2-TiO2solid superacid is used as catalyst in the esterification of cinnamic acid benzyl ester and stearic acid lauryl alcohol ester.The best condition of esterification has been discussed.After reaction the catalyst and esters are characterized by some technologies.The purpose of this paper is to find an environmentally friendly catalyst that has effect on the universal esterification and composite solid superacid catalyst for the use of large-scale industrialization.When using the Hammett acidity function Ho,the superacid is more powerful than100%sulfuric acid.The Ho value of100%sulfuric acid is-11.92.If the Ho value of a solid acid is lower than-11.92,it means that the solid acid is a superacid.The lower the Ho value,the stronger the acid.The research of solid superacid is starting at1970s.The japanese scientist M.Hino published a paper about SO42-/MxOy first-time at1979.The catalyst showed high catalytic properties.After that,scientists make efforts on the industrialization of solid superacid catalyst.As a new catalyst the solid superacid has many advantages.When compared with sulfuric acid,the solid superacid has stronger acid,won’t corrode the equipment and pollute the environment,and easy to separate from product.What’s more,the solid superacid has excellent catalytic activity on alkane skeleton isomerization,alkylation,olefin double bond isomerization,esterification reaction,and benzylation reaction.The esterification reaction is an important class of organic synthesis reactions.and its products are widely used.Cinnamic acid benzyl ester, is an important fine chemical science. It is available for preparation of spices, various flavor essence thinner and fixative agent.And it is also widely used in the Dengri and food industry. In the pharmaceutical industry, it is used to make anesthetics, fungicides, hemostatic. In the pesticide industry, as growth-pro-moting agents and long-acting fungicide for the preservative of fruits and vegetables. With the development of multi-functional packaging materials material, the ester can be used as spices of food wrappers. Stearic acid lauryl is widely used in producing cylinder lubricant and plastic. It also is a good additive in light industry, chemical industry and metallurgy.After reading numerous literature, I chose the right type of catalyst and start the preparation of it. After the preparation of catalyst,it is used to synthesize Cinnamic acid benzyl ester and Stearic acid lauryl.Both the esters and catalyst are characterized after reaction.Single factor experiment and orthogonal experiment are designed for the esterifica-tion of Benzyl cinnamate. The influence of feed ratio, reaction time, catalyst dosage, reaction temperature has been discussed.The best result of the experiment is that:feed ratio is1:8,reaction time is4h,catalyst dosage is6%and reaction temperature is130℃.After5times reuse, the esterification rate is still over90%.The orthogonal experiments confirm the results of Single factor experiments. In order to test the catalyst,the experiment for the esterification of Stearic acid lauryl has been designed. The best result of the experiment is that:feed ratio is1:1.1,reaction time is4h,catalyst dosage is4%and reaction temperature is140℃.The esterification rate is90.25%. After5times reuse,the esterification rate is higher than85%.The Ho value of the catalyst is tested by Hammett indicator method. The result of Ho value is that:-12.97<Ho<-11.99. The result means that the catalyst is a kind of solid superacid. The picture of SEM shows that, the specific surface area of the catalyst is enlarged by the preparation method. The roast temperature and the concentration of sulfuric acid are important factors in the preparation of catalyst.