Polyethylene dimethyl ether

GLYCOL MONOPHENYL ETHER see PEROOO GLYCOL MONOSTEARATE see EJM500 GLYCOLONITRILE see HIM500 GLYCOLS, POLYETHYLENE, DIMETHYL ETHER see DOMIOO... 

Carpol CLE 1000 Dimethoxy polyethylene glycol Genosorb 175 Genosorb 300 Glycols, polyethylene, dimethyl ether Glyme-23 a,(o-Methoxypoly(ethylene oxide) a-Methyl-o)-methoxypoly(oxy-... 

Glycols, Cl 5-18. See Cl 5-18 glycol Glycols, polyethylene, dimethyl ether. See PEG dimethyl ether... 

Synonyms Dimethoxy polyethylene glycol Glycols, polyethylene, dimethyl ether a,u)-Methoxypoly (ethylene oxide) Polyethylene glycol dimethyl ether Poly (oxy-1,2-ethanediyl), o-methyl-u-methoxy-Formula (C2H40)2C2He0 Toxicology TDLo (oral, male rabbit, 1 day premating) 2500 mg/kg reproductive effector TSCA listed... 

The solvent can be tailored to provide selective acid gas removal based on the Hquid—gas solubiHties. For example, the Selexol process, Hcensed by Union Carbide Corporation, uses the dimethyl ether of polyethylene glycol (DMPEG) to provide high hydrogen sulfide selectivity. The solubiHty of hydrogen sulfide in DMPEG is 8—10 times that of carbon dioxide. 

Selexol. licensed by the Norton Company, uses the dimethyl ether of polyethylene glycol. A Selexol plant can be designed to provide some selectivity for H2S. For example, the plant can be designed to provide pipeline quality gas (0.25 grains H S/IOOscf) while slipping 85% of the COi. ... 

With the discovery of the crowns and related species, it was inevitable that a search would begin for simpler and simpler relatives which might be useful in similar applications. Perhaps these compounds would be easier and more economical to prepare and ultimately, of course, better in one respect or another than the molecules which inspired the research. In particular, the collateral developments of crown ether chemistry and phase transfer catalysis fostered an interest in utilizing the readily available polyethylene glycol mono- or dimethyl ethers as catalysts for such reactions. Although there is considerable literature in this area, much of it relates to the use of simple polyethylene glycols in phase transfer processes. Since our main concern in this monograph is with novel structures, we will discuss these simple examples further only briefly, below. 

Chaput, Jeminet and Juillard measured the association constants of several simple polyethylene glycols with Na", K", Cs", and Tl". Phase transfer catalytic processes and most biological processes are more likely to involve the first two cations rather than the latter two, so we will confine the discussion to these. Stability constants for the dimethyl ethers of tetra-, penta-, hexa-, and heptaethylene glycols were determined poten-tiometrically in anhydrous methanol solution and are shown in Table 7.1. In the third column of the table, the ratio of binding constants (Ks/K s) is calculated. Note that Simon and his coworkers have referred to this ratio as the selectivity constant. ... 

Tetrasubstituted phosphonium halides are just as effective as their ammonium counterparts. A combination of tetraphenylphosphonium bromide and either 18-crown-6 or polyethylene glycol dimethyl ether with spray-dried potassium fluoride converts 4-chlorobenzaldehyde to 4-fluorobenzaldehyde in 74% yield [67] In addition, the halogen of a primary alkyl chloride or bromide is easily displaced by fluorine in aqueous saturated potassium fluoride and a catalytic amount of hexadecyltributylphosphonium bromide [68] (Table 7 Procedure 4, p 194)... 

Important processes commercially used are the Selexol, the Sulfinol, and the Rectisol processes. In these processes, no chemical reaction occurs between the acid gas and the solvent. The solvent, or absorbent, is a liquid that selectively absorbs the acid gases and leaves out the hydrocarbons. In the Selexol process for example, the solvent is dimethyl ether of polyethylene glycol. Raw natural gas passes countercurrently to the descending solvent. When the solvent becomes saturated with the acid gases, the pressure is reduced, and hydrogen sulfide and carbon dioxide are desorbed. The solvent is then recycled to the absorption tower. Figure 1-1 shows the Selexol process. ... 

Selexol Process Dimethyl Ethers of Polyethylene Glycol... 

Selexol Dimethyl Ether of Polyethylene Glycol None... 

PB PBI PBMA PBO PBT(H) PBTP PC PCHMA PCTFE PDAP PDMS PE PEHD PELD PEMD PEC PEEK PEG PEI PEK PEN PEO PES PET PF PI PIB PMA PMMA PMI PMP POB POM PP PPE PPP PPPE PPQ PPS PPSU PS PSU PTFE PTMT PU PUR Poly(n.butylene) Poly(benzimidazole) Poly(n.butyl methacrylate) Poly(benzoxazole) Poly(benzthiazole) Poly(butylene glycol terephthalate) Polycarbonate Poly(cyclohexyl methacrylate) Poly(chloro-trifluoro ethylene) Poly(diallyl phthalate) Poly(dimethyl siloxane) Polyethylene High density polyethylene Low density polyethylene Medium density polyethylene Chlorinated polyethylene Poly-ether-ether ketone poly(ethylene glycol) Poly-ether-imide Poly-ether ketone Poly(ethylene-2,6-naphthalene dicarboxylate) Poly(ethylene oxide) Poly-ether sulfone Poly(ethylene terephthalate) Phenol formaldehyde resin Polyimide Polyisobutylene Poly(methyl acrylate) Poly(methyl methacrylate) Poly(methacryl imide) Poly(methylpentene) Poly(hydroxy-benzoate) Polyoxymethylene = polyacetal = polyformaldehyde Polypropylene Poly (2,6-dimethyl-l,4-phenylene ether) = Poly(phenylene oxide) Polyp araphenylene Poly(2,6-diphenyl-l,4-phenylene ether) Poly(phenyl quinoxaline) Polyphenylene sulfide, polysulfide Polyphenylene sulfone Polystyrene Polysulfone Poly(tetrafluoroethylene) Poly(tetramethylene terephthalate) Polyurethane Polyurethane rubber... 

Low temperature methanol Dimethyl ethers of polyethylene glycol Di-isopropanolamine dissolved in sulfolane and water Monoethanolamine (MEA) or diglycolamine... 

The Selexol process removes acid gases from hydrocarbon gas streams by selective absorption in polyethylene glycol dimethyl ether (DMPEG). It absorbs H2S, C02, COS, and mercaptans. The process has been used to remove carbon dioxide from syngas, natural gas, and coal gas. The process was developed by Allied Chemical in the 1960s and is now... 

Ethers, such as tetrahydrofuran and 1,2-dimethoxyethane, have low dielectric constants (7.4 and 7.2, respectively), and the choice of supporting electrolyte is very limited. The ethers are difficult to reduce and are inert toward many metalorganic reagents [243] that are soluble in the ethers. Ethers are thus suitable as medium for the anodic addition of Grignard reagents to olefins [420]. Dimethoxyethane and polyethylene glycol dimethyl ethers have the ability to solvate electrons [421]. Dissociation constants for some acids and the relative strength of some bases in THE has been determined [422]. 

At high syngas pressure, physical solvent-based processes become increasingly attractive, for example, the Rectisol and Selexol processes. There are more than 55 Selexol plants worldwide, treating natural and syngas.51 The Selexol process solvent is a mixture of dimethyl ethers of polyethylene glycol, and has the formulation... 

DEPE, dimethyl ethers of polyethylene glycol MEA, monoethanolamine. 

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