| Summary: | 碩士 === 嘉南藥理科技大學 === 化妝品科技研究所 === 99 === Salicylate, a type of important compound that widely applied for various fields with cosmetics, sunscreen, food, and medicine. Most methods for synthesis of salicylate use concentrated sulfuric acid as a catalyst to proceed esterification of salicyclic acid and alcohol. Although the concentrated sulfuric acid is cheap and available, it causes that the reaction equipments are easily corroded, the post-processing is more complicated, and the environment is easily polluted. Therefore, developing a catalyst with high catalysis ability and environment-friendly is more interested with research.
This study is using 1-vinylimidazole (or imidazole) to react with alkyl bromide (or alkyl dihalide) with different alkyl chain and to different types of ionic liquid monomers. The brush chain types (PVImCmBr) or main chain types (PImCmCl) ionic polymers would be obtained by radical polymerization or self polymerization with these different types of ionic liquid monomers, and then through are anion-exchanged by sulfuric acid or phosphate acid to prepare twelve poly(ionic liquid) catalysts.
The experiment results reveal the poly(ionic liquid) catalysts perform good catalysis ability with esterfication reaction of salicyclic acid and alcohol. The catalysis ability of HSO4- anion is much higher than H2PO4-, and the alkyl chain length will not influence the catalysis ability. In this research, using 16a and 22a as catalyst can respectively achieve the catalysis yield of 89% and 90% and the yield of catalysis can also be achieved 70%~73% through five cycles. All experiment results show that the compounds 16a and 22a contain the highiest catalysis ability and reusability.
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