Ethylene oxide preparing polyethers from

Poly(alI lene glycol)s. While these can be made from polymeri2ation of any alkylene oxide, they are usually prepared either from propylene oxide as the water-insoluble type, or as water-soluble copolymers of propylene oxide and up to 50% ethylene oxide (35,36) (see Polyethers, propylene OXIDE polymers). Current worldwide production is estimated to be about 45,000 t. 

Other polyamine derivatives are used to break the oil/water emulsions produced at times by petroleum wells. Materials such as polyether polyols prepared by reaction of EDA with propylene and ethylene oxides (309) the products derived from various ethyleneamines reacting with isocyanate-capped polyols and quaternized with dimethyl sulfate (310) and mixtures of PEHA with oxyalkylated alkylphenol—formaldehyde resins (311) have been used. 

The Lagow group first entered the perfluoropolyethers field in 1977, by reacting fluorine with inexpensive hydrocarbon polyethers to prepare perfluoropolyethers. In the simplest case (Figure 14.3) poly (ethylene oxide) is converted to perfluoroethylene oxide polymer, a simple reaction chemistry that we first reported in the literature.27 As will be seen later, this direct fluorination technology as well as many new patents from Exfluor Research Corporation have been non-exclusively licensed to the 3M Corporation by the Lagow research group.3 "39... 

In most cases the catalytically active metal complex moiety is attached to a polymer carrying tertiary phosphine units. Such phosphinated polymers can be prepared from well-known water soluble polymers such as poly(ethyleneimine), poly(acryhc acid) [90,91] or polyethers [92] (see also Chapter 2). The solubility of these catalysts is often pH-dependent [90,91,93] so they can be separated from the reaction mixture by proper manipulation of the pH. Some polymers, such as the poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymers, have inverse temperature dependent solubihty in water and retain this property after functionahzation with PPh2 and subsequent complexation with rhodium(I). The effect of temperature was demonstrated in the hydrogenation of aqueous allyl alcohol, which proceeded rapidly at 0 °C but stopped completely at 40 °C at which temperature the catalyst precipitated hydrogenation resumed by coohng the solution to 0 °C [92]. Such smart catalysts may have special value in regulating the rate of strongly exothermic catalytic reactions. 

Polyethers are prepared by the ring opening polymerization of three, four, five, seven, and higher member cyclic ethers. Polyalkylene oxides from ethylene or propylene oxide and from epichlorohydrin are the most common commercial materials. They seem to be the most reactive alkylene oxides and can be polymerized by cationic, anionic, and coordinated nucleophilic mechanisms. For example, ethylene oxide is polymerized by an alkaline catalyst to generate a living polymer in Figure 1.1. Upon addition of a second alkylene oxide monomer, it is possible to produce a block copolymer (Fig. 1.2). 

The first report of the copolymerization of an epoxide, namely, ethylene oxide and C02 is contained in a patent by Stevens [6]. However, this process, when carried out in the presence of polyhydric phenols, provided polymers which were viscous liquids or waxes possessing copious polyether linkages with only a few incorporated C02 units. The earliest metal-catalyzed copolymerization of epoxides and C02 was reported in 1969 by Inoue and coworkers, who employed a heterogeneous catalyst system derived from a 1 1 mixture of diethylzinc and H20 [7, 8], Subsequently, Kuran and coworkers investigated a group of related catalysts prepared from diethylzinc and di- and triprotic sources such as pyrogallol, with a slight improvement over Inoue s system for the production of polypropylene carbonate) from PO and C02 [9],... 

Most addition polymers are prepared from vinyl monomers. However, another type of addition polymer can be formed by ring-opening reactions. For example, the polymerization of ethylene oxide can be accomplished by treatment with a small amount of a nucleophile, such as methoxide ion. The product, a polyether, is formed by a mechanism involving anionic intermediates ... 

Ambient temperature molten salt can be obtained by several methods. One effective way to obtain a room-temperature molten salt is by the introduction of polyether chains to ions. The term polyether/salt hybrid is used in this chapter as a common name for polyether oligomers having anionic or cationic charge(s) on the chain (Figure 22.1). Polyethers, such as poly-(ethylene oxide) (PEO), are known as representative ion conductive polymers [1]. Polyether/salt hybrids have been studied as a kind of room-temperature molten salt apart from the development of onium-type ionic liquids [2]. The preparation of ionic liquids consisting of metal ions has been one of the important goals in this research field. Polyether/salt hybrid derivatives give one such solution for this task. 

The interaction of a catalyst with impurities can also lead to an increase in catalyst activity. Polyether polyols prepared from ethylene oxide or propylene oxide are often prepared with potassium hydroxide as a catalyst. Residual catalyst in the polyol has been shown to increase the reaction rate with DBTDL. 

When uncatalyzed, primary alcohol groups react with isocyanates two or three times as fast as secondary alcohol groups, whereas the presence of catalysts, particularly metal catalysts, cause an even greater spread in reactivity between primary and secondary alcohol groups (20-22). Recently Knodel ( ) reported the use of mixtures of ethylene oxide and propylene oxide in the preparation of polyether polyols from solid polyol initiators such as sucrose in the presence of trimethyl- or triethylamine as catalysts. This process was said to reduce the preparation time for the polyether polyols by as much as 67 percent, and the viscosity of the resulting polyether polyol was lower than in conventional processes using propylene oxide as the sole alkylene oxide. 

It is now well established that solvent-free films can be cast from solutions of polyethers (such as poly(ethylene oxide)) and alkali metal salts, and that these films can display high ionic conductivity. Most of the effort devoted to this field has been based on the potential of such materials as solid-state electrolytes for battery applications. In this context, from viewpoints of both ionic mobility and weight, lithium salts in PEO have attracted the most intensive research and appear to offer the most promise such materials are discussed elsewhere. The preparation of materials displaying both electronic and ionic conductivity raises interesting possibilities both in the field of batteries and sensors and is beginning to attract attention (16). 

Hydroxy-terminated polyethers have now assumed a dominant role in the commercial production of polyurethanes. The most widely used polyethers are derivatives of propylene oxide and these polymers are described in Section 8.4.3.1. Linear, glycol-initiated propylene oxide polymers and propylene oxide-ethylene oxide block copolymers find some use in the preparation of elastomers. Polyether triols of relatively high molecular weight (about 3000) are extensively used for the production of flexible foams whilst polyols of low molecular weight (about 500) are used for rigid foams and surface coatings. Poly(oxytetramethylene) glycols prepared from tetrahydrofuran (Section 8.4.6) are used for the preparation of elastomers and spandex fibres. 

By anionic procedures, Teyssie and his coworkers prepared block copolymers of types AB, ABA, and BAB from tert-hniyl methacrylate and ethylene oxide. The initiators studied were (PhCHPh)K and K(naphthalene). Upon hydrolysis, polyacid-polyether block copolymers were formed [28]. 

The reaction is usually carried out at high temperatures (of about 200°C) in a polar solvent, such as tetramethylene sulfone, and the polyamide formation can be accelerated by the addition of l-phenyl-3-methyl-2-phospholene 1-oxide as catalyst. However, in the case of a two-step process, the reaction time of the first step must be carefully controlled, since the catalyst can also play a role in the formation of carbodiimides from two terminal isocyanate groups [36], These carbodiimides can then further react and lead to crosslinking [36], In most cases [34-39], the polymers are prepared with 4,4 -methylene bis(phenyl-isocyanate) (MDI), using adipic acid, isophtahc acid, azelaic acid, or a mixture of two of them (in order to accelerate the solubilization of the polyamide phase in the solvent) and a polyether based on tetramethylene oxide, ethylene oxide, or a mixture of propylene oxide and ethylene oxide. 

Propylene oxide has found use in the preparation of polyether polyols from recycled poly(ethylene terephthalate) (264), haUde removal from amine salts via halohydrin formation (265), preparation of flame retardants (266), alkoxylation of amines (267,268), modification of catalysts (269), and preparation of cellulose ethers (270,271). 

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