Study Of Catalyst Performance And Catalytic Mechanism Of Transesterification Using Ionic Liquids As Catalysts

At room temperature ionic liquid is liquid and has the low vapor pressure. It is also known as the green solvent. By choosing appropriate cation, anion and ligand, ionic liquid can be changed chemical and physical properties. As a kind of environmental friendly reaction medium, ionic liquid is a new type of green solvent and catalyst, it can make the response better, improving the reaction yield and the application in clean with attractive prospect of catalysis.Diaryl Carbonates which can be used in formulating lubricants is a species of important raw material of organic synthesis with low pour points, excellent lubricating properties, high thermo-oxidative stability, and completely miscible with hydrocarbon oils. Nowdays, most of Diaryl Carbonates were obtained by transesterification of DMC by aliphatic alcohols using Lewis acid and alkali as catalysts. The yeild of Diaryl Carbonates was low.In the thesis; we investigated the synthesis of ionic liquids with different structure. Then catalyze the transesterification of DMC and aliphatic alcohols to obtained Diaryl Carbonates. The catalysts were low pollution and high efficiency.The diversification of ionic liquids provide a multiple choice for chemistry workers, but at the same time how to select the most appropriate ionic liquids from many ionic liquids also become a problem. How to design ionic liquids according to the needs of various research works become the goal of ionic liquids research workers in the21st century. Therefore, the hope of the discovery of catalytic mechanism and catalytic performance in catalytic transesterification reaction study has important significance in the field of the ionic liquid as catalyst.The major works are as follows:(1)Five basic ionic liquids [Rmim]Im(R=4C、5C、6C、7C、8C) were synthesized, its structure were unambiguously confirmed by FT-IR spectrometry.(2)Diaryl Carbonates (Dibutyl Carbonate, Dipentyl Carbonate, and Dihexyl Carbonate) were synthesis by transesterification of DMC by aliphatic alcohols using these five basic ionic liquids which have different carbon chain length.Finding the optimal catalyst and reaction conditions were optimized by orthogonal experiments, to achieve maximum catalytic efficiency.(3)The structure of Dibutyl Carbonate, Dipentyl Carbonate, and Dihexyl Carbonate were charactered by FT-IR spectrometry. The structure of Dihexyl Carbonate and [Pmim]Br were confirmed by1HNMR and13CNMR spectrometry.(4) Mechanism of transesterification reaction catalyzed by Ionic liquids.