Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/59118
標題: 超音波輔助雙活性基相間轉移觸媒在多相系統合成羥基苯甲酸酯類之研究
Ultrasound-Assisted Dual-Site Phase-Transfer Catalysis for Synthesizing Hydroxybenzoates in Multiphase System
作者: 楊鴻銘
關鍵字: 技術發展
Ultrasound
化學工程類
超音波
雙活性基相間轉移觸媒
固-液相
第三液相
酯化反應
動力學
Dual-site phase-transfer catalysis
solid-liquid phases
third-liquidphase
esterification
kinetics
摘要: 本計畫在探討應用超音波輔助雙活性基相間轉移觸媒在固-液相及液-液-液三相合成羥基苯甲酸酯類化學品,探討雙活性基觸媒在超音波放射下於固-液相系統之催化性能及其形成第三液相之條件、反應機制與反應動力學等,建立超音波輔助雙活性基相間轉移催化酯化反應的程序。由於不需使用昂貴的非質子溶劑及有害環境的含鹵素溶劑,因此是對環境親和的綠色化學技術。以苯甲酸為主的酯類廣泛用於調合香料的基材、化粧品香水、食品調味劑等,亦可用於瓷漆、纖維素衍生物及可作為液晶材料之添加劑。以對-羥基苯甲酸所合成的酯類則作為防日晒油、乳霜和化妝水之芳香劑、溶劑。以往製造含取代基苯甲酸酯類的程序,是以其對應醇類在硫酸的催化下進行酯化反應來合成,反應條件嚴苛、反應速率慢、且因可逆反應與水解副反應而有產率低的缺點,也因使用硫酸觸媒,反應器材質需特別考慮,應用相間轉移觸媒的酯化反應製程則可改善這些缺點。由於相間轉移觸媒具有增進兩不互溶反應物的反應速率,且其反應條件溫和、轉化率及產物選擇率高,若相間轉移觸媒具有多個活性基位,則可促進催化反應速率。因此若將酯化反應方式改變成固-液相雙活性基相間轉移觸媒及將觸媒集中於第三液相之反應程序,與超音波技術結合,則可在溫和條件下使用環境親和溶劑來合成高價值化學品並提高其轉化率及產率,對製程經濟性將有極大的改善。本計畫探討在超音波放射下固-液相與液-液-液三相系統之反應現象,期能對多相相間轉移催化技術及其界面催化的理論有進一步的發展。本計畫為三年度之研究計畫,其目標及預定工作項目如次:第一年進行超音波固-液相系統研究,深入探討在超音波放射下之固-液界面催化反應機制、雙活性基觸媒中間體之合成、質傳現象,水量效應及本質反應速率等;第二年進行第三液相之形成研究,以第一年之研究結果為基礎,在超音波放射條件下,探討水相反應物、鹽類、雙活性基相間轉移觸媒對第三液相形成之效應,雙活性基觸媒中間體與有機相反應物之本質反應速率,三液相之分佈、質傳現象與界面反應機構,操作變數對總體反應速率之影響等,並建立反應系統之動力學模式。第三年則進行超音波輔助之液-液-液三相續流式反應系統之研究,以前兩年之研究為基礎,探討雙活性基觸媒在續流式反應之催化行為、反應機制、觸媒分布、超音波效應等,並建立續流式液-液-液相催化反應系統模式,本計畫研究結果將可提供未來反應程序設計的基礎。
This proposal is to investigate the application of dual-site phase-transfer catalyst forsynthesizing hydroxybenzoates via ultrasound-assisted phase transfer catalysis in solid-liquidand liquid-liquid-liquid phases. The catalytic activity of dual-site phase-transfer catalyst insolid-liquid phases and the formation of the third-liquid phase under ultrasonic irradiation,reaction mechanism, and kinetics will be explored to setup the process of ultrasound-assisteddual-site phase-transfer catalysis. It is an environmentally friendly technology due to withoutusing halide-containing or aprotic solvents.The benzoates are widely used as flavoring agents, perfumery, lacquers and solvent forcellulose derivatives, and as an additive in liquid crystal materials. p-Hydroxybenzoates areused in perfumery, sunscreeing agent, etc. In the past, the manufacturing processes forsubstituted benzoates were to conduct esterification reaction with the corresponding alcoholsin the presence of sulfuric acid, and having the disadvantages of severe reaction conditions,slow reaction rates, and low yields due to reversible reactions and hydrolysis side recations.Moreover, the materials of reactors should be specially considered due to the use of sulfuricacid. Those drawbacks can be overcome by applying phase-transfer catalyzed esterificationprocesses. Since phase transfer catalysts can be employed to enhance the reaction ofimmiscible reactants under mild conditions with high conversion and high product selectivity.If a molecule of catalyst contains multi-site, it can largely increase the reaction rate. Thus it isvaluable to change the traditional manufacturing method into solid-liquid and tri-liquidphase-transfer catalyzed esterification processes combined with ultrasonic technology togreatly enhance the product yield. This project is willing to explore the activity of dual-sitephase transfer catalysts in solid-liquid phases and in liquid-liquid-liquid under ultrasonicirradiation. It is expected to develop the related theory of phase transfer catalysis.This proposal is willing to be completed within three years. The goal and items doneare as follows. For the first year, the interfacial mechanism and kinetics in solid-liquid phasesunder ultrasound are going to be investigated. The synthesis of dual-site phase-transfercatalytic intermediate will be performed, and the effect of mass transfer and the intrinsicreaction of the catalytic intermediate as well as the influence of water on the overall reactionswill be explored. For the second year, in a liquid-liquid-liquid system under ultrasonicirradiation, the conditions of forming the third-liquid phase with dual-site PTC, the catalystdistribution between phases, the mass transfer effect, the interfacial mechanism and kineticsof the overall reaction will be investigated. The kinetic model is also developed to describethe interfacial reactions in tri-liquid system. For the third year, a continuous flow system forliquid-liquid-liquid phases under ultrasonic irradiation will be employed to investigate thecatalytic activity of dual-site phase-transfer catalyst, reaction mechanism, catalyst distribution,and the effect of ultrasound, etc. The system model for liquid-liquid-liquid phases will bedeveloped. The research results can be used as the basis for reactor design in the future.
URI: http://hdl.handle.net/11455/59118
其他識別: NSC99-2221-E005-092
文章連結: http://grbsearch.stpi.narl.org.tw/GRB/result.jsp?id=2122162&plan_no=NSC99-2221-E005-092&plan_year=99&projkey=PB9907-2461&target=plan&highStr=*&check=0&pnchDesc=%E8%B6%85%E9%9F%B3%E6%B3%A2%E8%BC%94%E5%8A%A9%E9%9B%99%E6%B4%BB%E6%80%A7%E5%9F%BA%E7%9B%B8%E9%96%93%E8%BD%89%E7%A7%BB%E8%A7%B8%E5%AA%92%E5%9C%A8%E5%A4%9A%E7%9B%B8%E7%B3%BB%E7%B5%B1%E5%90%88%E6%88%90%E7%BE%A5%E5%9F%BA%E8%8B%AF%E7%94%B2%E9%85%B8%E9%85%AF%E9%A1%9E%E4%B9%8B%E7%A0%94%E7%A9%B6
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