Kinetic Study of Synthesizing Ether Compounds under Phase Transfer Catalysis

• Main Authors: Ze-Fa Lee, 李至發
• Other Authors: Feng-Sheng Wang
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/50462842029742270839

博士 === 國立中正大學 === 化學工程所 === 94 === In this dissertation, the reaction of alcohol with haloalkane or haloalkene to synthesize ether compounds in a two-phase alkaline solution of KOH/organic solvent medium under phase transfer catalysis (PTC) was investigated. Those products from PTC reaction can be used as the liquid crystal materials, perfume, epoxidised adhesives for semiconductor chips, and photoresists etc. in industries. The primary purposes of this dissertation are to study the phase-transfer catalytic reaction for ether compounds, reaction mechanism, kinetics, mass transfer effect, distribution of active catalyst and other related theories. Several rigid conclusions were obtained from the experimental results. (a) In the present study, systems are confined within the di-substituted etherification reactions. In part 1, both mono-substituted and di-substituted of 4,4’-bis(chloromethyl)-1,1’- biphenyl-derived were obtained. However, only di-substituted product, bisphenol A diallyl ether, was obtained in part 2 reaction system. The result indicates that a rapid second organic reaction in the organic phase for the second reaction system. (b) High purity products were obtained by using the pressurized column chromatography with appropriate choosing eluent species and adsorbing materials. (c) A threshold value of two-phase mass-transfer rate would exist in the phase transfer catalytic reactions. All reaction systems were identified as the extraction mechanism. The reaction was organic reaction controlled when the agitation speed was higher than the threshold value. (d) The biphasic etherification reactions were effectively enhanced in the mild conditions via phase-transfer catalysis, especially for the reaction system of bisphenol A diallyl ether. The etherification via phase-transfer catalyst could operate at lower temperature to avoid intramolecular rearrangement, which usually occurs at higher temperature. (e) As the results of experiments, the rate was increased with the increase in amount of catalyst, temperature, as well as organophilicity and symmetry of catalyst cation. Alkali salt is used to decrease solvation of active catalyst. It enhances the solubility and ionization of the aqueous reactants. However, the aqueous reactants were precipitated by using larger amount of alkali salt in the reaction of phenol with 4,4’-bis(chloromethyl)-1,1’-biphenyl in part 1 and all reaction systems in part 2. For this reason, the addition of alkali salt exist an optimum value. (f) The pseudo steady-state hypothesis (PSSH) and two-film theory are successfully applied to develop the reaction mechanism. The apparent rate constants were determined from the experimental data in conjunction with the computer program. (g) The uniform polymer-supported particles were obtained by adding the steric stabilizer during polymerization. After tertiary amines were immobilized on polymer supported particles, the tirphase catalysts perform excellent catalytic activity and reusability. (h) The synthesized multi-site phase-transfer catalysts, which were obtained from low cost 4,4’-bis(chloromethyl)-1,1’-bipehnyl with tertiary amines, show superior catalytic reactivity in both reaction systems. (i) In catalytic reaction systems, the reaction is greatly enhanced with the addition of surfactants or co-catalyst.