Insoluble Phase-Transfer Catalysts

Abstract

catalysts requires extensive development and special manufacturing that cause cost and time problems frequently judged to be too high to justify their industrial use.2. The cost of resin-bound PTC catalysts is usually prohibitively high if a special catalyst composition is required. Commercially available ion-exchange resins sometimes show excellent behavior as resin-bound PTC catalysts, and these pose few barriers to commercial use. Insoluble PTC catalysts made by adsorbing simple quaternary ammonium cations on organophilic clays appear to provide the least expensive and most robust materials suitable for commercial use.3. Solid insoluble PTC catalysts generally lack the robust physical and chemical stability necessary to survive repeated use for long periods in industrial-scale reactors. This barrier can often be overcome or significantly reduced by sufficient development work with the reaction system being studied.4. Insoluble liquid PTC catalysts, although not particularly affected by the above problems, require much more time during the process development stage to obtain an industrially useful process. Such systems have not been extensively explored, although several examples of such reaction systems are described in Section D of this chapter. These systems, once developed, can be extremely useful.As technology for insoluble PTC catalyst preparation and use expands, costs decrease, and recyclability increases, it is expected that insoluble PTC catalysts will become the dominant type for conducting industrial-scale PTC reactions [1].Regen and co-workers [2] were the first to demonstrate that quaternary salts chemically bound to insoluble resins could function as phase-transfer catalysts, and coined the term triphase catalysis to describe this special branch of PTe. This name is now generally used for all types of PTC catalysts bound to, adsorbed on, or consisting of any insoluble solid whether organic or inorganic. Tomoi and Ford [3], however, suggest the more specific name, polymer-supported phase-transfer catalysis, to describe reactions that occur within the polymer gel phase. Both these terms, as well as resin-bound PTC catalyst or clay-supported PTC catalyst, are used in this chapter.The remainder of this chapter is divided into three general sections: the first deals with resin-bound PTC catalysts, the second with PTC catalysts on inorganic supports, and the third with insoluble liquid PTC systems.

Cotton Fabric-Supported Cationic Acrylate Polymer as an Efficient and Recyclable Catalyst for Williamson Ether Synthesis Reaction in Solid–Liquid–Liquid Phase Transfer Catalysis System

“…The SLL-PTC system with the immobilized catalyst can overcome these drawbacks and exhibits excellent easy removal and subsequent reusability of the catalyst. 8 , 9 The SLL-PTC system has been one of the most promising industrial system.…”

“…However, the introduction of the third liquid phase into the PTC system always induced that the emulsion between the liquid phases exited and the separation of the phase was more difficult than that in the biphasic PTC system, which limited the application in industry. The SLL-PTC system with the immobilized catalyst can overcome these drawbacks and exhibits excellent easy removal and subsequent reusability of the catalyst. , The SLL-PTC system has been one of the most promising industrial system.…”

Chemical kinetics of carbon dioxide with glycidyl methacrylate using immobilized tributylamine supported on poly(styrene-co-vinylbenzyl chloride) as a catalyst

“…[5][6][7] Quaternary onium salts are bound to polymer resins 6 such as styrene-divynyl benzene related resins, which is used as an ion-exchange resin support. 8 The polymer-supported catalysts can be easily separated from reaction mixtures and can be reused.…”