Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/59087
標題: 多活性基相間轉移觸媒之製備及應用在超音波輔助三液相相間轉移催化合成取代基苯甲酸酯類之研究
Preparation of Multi-Sites Phase Transfer Catalysts for Synthesizing Substituted Benzoic Acid Esters via Ultrasound Assisted Tri-Liquid Phase-Transfer Catalysis
作者: 楊鴻銘
關鍵字: 基礎研究
Multi-site phase-transfer catalyst
化學工程類
多活性基相間轉移觸媒
第三液相
超音波
酯化反應
綠色技術本計畫屬於化學工程學門重點規劃主題(2)綠色化學製程與材料研究
third-liquid phase
ultrasound
esterification
green technology
摘要: 第三液相相間轉移催化反應不需使用昂貴的無水或非質子溶劑及危害環境的含鹵素溶劑,是對環境親和的綠色化學技術,其優點為:可提高反應選擇性、反應速率與產率,產物容易分離且反應條件溫和,觸媒可回收與重複利用。第三液相含有高濃度的活性觸媒,性質介於親水親油之間,水相和有機相反應物均可進入此相內進行反應,在溫和條件下提高反應速率。一般相間轉移觸媒僅具有單一活性基位,一次僅能攜帶一分子的水相反應物進行反應,若能使一分子的觸媒具有多個活性基位,則可大幅促進催化反應速率。當多活性基觸媒集中在第三液相時,第三液相之界面特性隨之變化,可高度催化反應的進行,因此多活性基相間轉移觸媒之合成與應用是相間轉移催化技術發展的方向之一。超音波化學為合成化學品極有效的技術,當高頻超音波在液體溶液中傳送時,造成溶液中漸歇式的壓縮與釋壓而形成局部空穴,空穴中之氣體溫度及壓力瞬間可達5000K 與數百大氣壓,有利於反應進行。因此若將多活性基第三液相相間轉移觸媒技術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產率。本計畫之研究目的即在以超音波輔助多活性基第三液相相間轉移觸媒由含取代基苯甲酸鹽類來合成酯類特用化學品,可應用於調合香料的基材、化粧品香水、食品調味劑、瓷漆、纖維素衍生物及可作為液晶材料之添加劑等。本計畫分兩年完成,第一年:合成多活性基相間轉移觸媒及其第三液相形成條件,並探討由超音波促進之批式第三液相觸媒催化酯化反應之聯合效應,第二年則進行續流式超音波促進多活性基第三液相觸媒催化酯化反應製程之研究。本計畫預定之工作項目:第一年,探討中心分子結構對多活性基觸媒之合成條件、不同超音波頻率輔助之水相反應物、鹽類、相間轉移觸媒對第三液相形成之效應,對多活性基觸媒中間體之生成效應,超音波促進之有機相本質反應速率,三液相界面特性及反應機構,及操作變數對總體反應速率之影響等;第二年,設計超音波輔助之續流式三液相反應程序,探討第三液相觸媒之回用程序,觸媒結構之效應、超音波頻率效應、反應機構等,並建立續流式液-液-液相催化反應系統模式。本計畫所獲結果可提供第三液相相間轉移觸媒製程設計以合成酯類特用化學品。
The third-liquid phase-transfer catalysis (TL-PTC) is an environmentally benigntechnology in organic synthesis without using expensive aprotic or halide-containing solvents.Its advantages include higher selectivity and product yield, higher reaction rate, easierseparation of products, mild reaction conditions, and the recovery and reuse of catalysts. Thethird-liquid phase contains highly concentrated active catalysts, with the property betweenhydrophilicity and hydrophobicity. Both the aqueous and organic reactants can transfer intothis phase to conduct reactions under mild conditions in a high reaction rate. In general, PTCoffers only one active site and can transfer one molecule of aqueous reactant once. If onemolecule of PTC has more than one site, the reaction rate can be greatly enhanced. In addition,as the multi-site catalyst is highly concentrated in the third-liquid phase, the reaction rate canbe highly promoted. Thus, the synthesis of multi-site PT catalysts becomes one of importantdevelopments in PTC technology. Sonochemistry is an effective technique in synthesizingchemicals. When the high-frequency ultrasound propagates in a liquid solution, the alternatecompression and depression are produced to form the cavities where temperature and pressurecan reach 5000 K and several hundred bars to enhance the reaction. Hence, the combinationof multi-site third-liquid PTC and ultrasound can result in a high product yield of high-valuechemicals using the environmentally friendly solvents.The purpose of this project is to develop the ultrasound assisted multi-site third-liquidphase-transfer catalysis for the esterification of benzoate salts to synthesize esters specialtychemicals, which are widely used as flavoring agents, perfumery, lacquers and solvent forcellulose derivatives, and as an additive in liquid crystal materials. This project will becompleted in two years. For the first year, the conditions for synthesizing multi-site PTC andforming the third-liquid phase will be explored. The synergism effect on the ultrasoundfacilitated multi-site third-liquid phase catalyzed esterification will be investigated; for thesecond year, using continuous-flow tri-liquid-phase reactor to explore the multi-sitethird-liquid catalyzed esterification will be performed. The research items are (1) for the firstyear, the effect of central molecular structure on preparing multi-site PTC, effects ofultrasound on forming the third-liquid phase from aqueous reactant, catalyst, and salts as wellas the production of catalytic intermediate, the intrinsic organic reaction, interfacialcharacteristics of third-liquid phase, reaction mechanism, and kinetics, and (2) for the secondyear, the development of ultrasound assisted continuous-flow process in tri-liquid phases, thereuse of multi-site third-liquid catalyst, effects of catalyst structure and frequencies ofultrasound, the reaction mechanism, and the kinetic model. The research results can be used todesign the TL-PTC process for synthesizing esters specialty chemicals in the future.
URI: http://hdl.handle.net/11455/59087
其他識別: NSC97-2221-E005-042
Appears in Collections:化學工程學系所

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