Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/59135
標題: 超音波輔助新穎雙活性基相間轉移觸媒在三相系統合成羥基苯甲酸酯類之研究
Synthesis of Hydroxybenzoic Acid Esters by Ultrasound-Assisted Novel Dual-Site Phase-Transfer Catalyst in Tri-Phase System
作者: 楊鴻銘
關鍵字: 商品化;化學工程類;超音波;雙活性基相間轉移觸媒;第三相;酯化反應;動力學
摘要: 
This proposal is to investigate the application of dual-site phase-transfer catalyst tosynthesize hydroxybenzoates via ultrasound-assisted phase transfer catalysis with the third orthird-liquid phase in a batch reactor or continuous-flow reactor. The formation of thethird-liquid or third phase and the catalytic activity of dual-site phase-transfer catalyst underultrasonic irradiation, reaction mechanism, and kinetics will be explored. The purpose of thisproposal is to setup the green process of ultrasound-assisted dual-site phase-transfer catalysis,which behaves high product yield and is an environmentally benign technology without usinghalide-containing solvents.Phase transfer catalysts have been employed to enhance the reaction of immisciblereactants under mild conditions with high conversion and high product selectivity. If amolecule of catalyst contains dual sites, it can be used to increase the reaction rate more andmore. Thus it is valuable to change the traditional manufacturing method into a phase-transfercatalyzed esterification processes with third phase which is highly concentrated in a separatephase and can be easily separated and recovered from the reaction mixture. The ultrasoundtechnology has been proved to greatly enhance the rate of chemical reaction and product yield.Hence, this proposal is willing to explore the activity of dual-site phase transfer catalysts intri-phase system under ultrasonic irradiation. It is expected to develop the related theory ofphase transfer catalysis and interfacial catalysis.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.This proposal is the extended work of the last project and is willing to be completedwithin two years. The goal and items done are as follows. For the first year, the formation ofthe third-liquid or the third phase by the novel dual-site phase-transfer catalyst will beexplored. Effects on the third phase formation investigated will include the aqueous reactant,inorganic salt, dual-site PTC and reaction conditions, etc. the reactivity of dual-site PTC withthe organic reactant and the distribution of the catalytic intermediate between the tri-phases,the interfacial reaction mechanism and kinetics of the overall reaction under ultrasoundirradiation. The kinetic model is also developed to describe the interfacial reactions intri-phase system. For the second year, a continuous flow reactor system with ultrasoundirradiation will be set-up and employed to investigate the catalytic activity of dual-sitephase-transfer catalyst, reaction mechanism, catalyst distribution, and the effect of ultrasound,etc. The system model for the continuous flow reactor in tri-phases will be developed. Theresearch results can be used as the basis for reactor design in the future.

本計畫在探討應用超音波輔助雙活性基相間轉移觸媒於三相系統在批式反應器及續流式反應器合成羥基苯甲酸酯類化學品,探討雙活性基觸媒形成第三液相或第三相之條件、及其在超音波輔助下之催化性能、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。由於反應方法具有高產物產率及不使用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。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,而具有雙重活性基位的相間轉移觸媒,更可促進催化反應速率。當雙活性基相間轉移觸媒集中於第三液相或形成固液共存之第三相時,可提昇觸媒反應之效率;第三相或第三液相之催化反應系統不僅具有高催化活性,更因觸媒高度集中於水油以外的相,而具有觸媒易於分離與回收之優點,與超音波技術結合時,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。本計畫探討在超音波放射下三相系統之雙活性基催化反應現象,期能對相間轉移催化技術及其界面催化的理論有進一步的發展。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。本計畫為延續上年度計畫之二年期研究計畫,其目標及預定工作項目如次:第一年進行新穎雙活性基相間轉移觸媒之第三液相與第三相形成研究,探討水相反應物、鹽類、雙活性基相間轉移觸媒及反應條件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及其在三相之分佈情形,在超音波放射條件下界面反應機制,操作變數對總反應速率之影響等,並建立反應系統之動力學模式。第二年則進行超音波輔助雙活性基相間轉移觸媒之三相續流式反應程序研究,以第一年研究結果為基礎,探討雙活性基觸媒在續流式反應器之催化行為、反應機制、觸媒分布、超音波效應等,並建立雙活性基觸媒之三相續流式催化酯化反應模式,本計畫研究結果將可提供未來反應程序設計的基礎。
URI: http://hdl.handle.net/11455/59135
其他識別: NSC100-2221-E005-049
Appears in Collections:化學工程學系所

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