Solvents from ethylene oxide

Other Derivatives. Ethylene carbonate, made from the reaction of ethylene oxide and carbon dioxide, is used as a solvent. Acrylonitrile (qv) can be made from ethylene oxide via ethylene cyanohydrin however, this route has been entirely supplanted by more economic processes. Urethane intermediates can be produced using both ethylene oxide and propylene oxide in their stmctures (281) (see Urethane polymers). 

The large volume solvents, trichloroethylene and perchloroethylene, are still chiefly made from acetylene, but appreciable amounts of the former are derived from ethylene. The competitive situation between these source materials runs through the whole chlorinated hydrocarbon picture, and extends on to other compound classes as well—for example, acrylonitrile is just on the threshold of a severalfold expansion, as demand grows for synthetic fibers based thereon. Acrylonitrile can be made either from ethylene oxide and hydrogen cyanide, from acetylene and hydrogen cyanide, or from allylamines. The ethylene oxide route is reported to be the only one in current commercial use, but new facilities now under construction will involve the addition of hydrogen cyanide to acetylene (27). 

While hundreds of materials probably could fulfill the broad requirements of a solvent for the extraction of pollutants, in this example we will start our investigation with work done at the University of Alabama on a process called biphasic extraction. Homopolymers and copolymers (referred to in this book as polyols) use components made from ethylene oxide (EO) and blends of ethylene oxide and propylene oxide (PO), respectively. Since they are soluble in water, they are not useful in solvent extraction schemes. 

However, if in nonaqueous solutions (discussed next) the oxidations also proceed through oxypalladation adducts, then the two mechanisms of decomposition of the oxypalladation adducts would predict diflFerent products. First, let us consider the mechanism of Jira, Sedlmeier, and Smidt (Reactions 50-53). In this case OH in II (Reaction 52) is replaced by OR. Decomposition via Reaction 55 is impossible, so II must decompose by solvolysis. This would give 1,1-disubstituted ethanes from ethylene oxidation. On the other hand, the first suggestion (Reaction 48) would probably be more consistent with formation of the vinyl compounds since hydride elimination should be completed if a rapid rearrangement of electrons to give acetaldehyde cannot occur. Evidence exists that 1,1-disubstituted ethanes are the initial products in methanol, and in acetic acid it is claimed that both vinyl acetate and 1,1-diace-toxyethane are initial products this suggests that in this solvent competition exists between palladium (II) hydride elimination and acetate attack. However, until now there have been no detailed studies of the oxidation under conditions where 1,1-disubstituted products are formed. More work is needed before the course of the reaction under these conditions is completely understood. 

CH3CH2OCH2CH2OH (ethyl cellosolve) and CH3CH2OCH2CH2OCH2CH2OH (ethyl carbitol) are solvents used in the formulation of lacquers. They are produced commercially from ethylene oxide and certain other reagents. Show with equations how this might be done. 

Most acetate esters, however, are produced from acetaldehyde using the Tishchenko reaction. In addition, ether acetates are used as solvents for nitrocellulose, acrylic lacquers, varnish removers, and wood stains. First, glycol monoethers are produced from ethylene oxide or propylene oxide with alcohol, which are then esterified with acetic acid. The three major products are ethylene glycol monoethyl ether acetate (EEA), ethylene glycol monobutyl ether acetate (EBA), and propylene glycol monomethyl ether acetate (PMA, more commonly known as PGMEA in semiconductor manufacturing processes, where it is used as a resist solvent). This application consumes about 15% to 20% of worldwide acetic acid. Ether acetates, for example EEA, have been shown to be harmful to human reproduction. 

Homogeneous films were prepared from ethylene oxide substituted ppo 4.16 studied for their gas separation characteristics. These dense films were prepared from a solution of the modified polymer in a chloroform-methanol solvent mixture. The permeabilities for CO2 and O2 for these films were 24 and 4.8 Barrer respectively. Permeability ratios for CO2/CH4 and O2/N2 gas pairs were 20.0 and 4.0. ... 

Catalysts. Silver and silver compounds are widely used in research and industry as catalysts for oxidation, reduction, and polymerization reactions. Silver nitrate has been reported as a catalyst for the preparation of propylene oxide (qv) from propylene (qv) (58), and silver acetate has been reported as being a suitable catalyst for the production of ethylene oxide (qv) from ethylene (qv) (59). The solubiUty of silver perchlorate in organic solvents makes it a possible catalyst for polymerization reactions, such as the production of butyl acrylate polymers in dimethylformamide (60) or the polymerization of methacrylamide (61). Similarly, the solubiUty of silver tetrafiuoroborate in organic solvents has enhanced its use in the synthesis of 3-pyrrolines by the cyclization of aHenic amines (62). 

Butyl glycol ethers, the largest volume derivatives of -butyl alcohol used ia solvent appHcations (10), are obtained from the reaction of 1-butanol with ethylene oxide. The most important of these derivatives, 2-butoxyethanol, is used principally ia vinyl and acryHc paints as well as ia lacquers and varnishes. It is also employed ia aqueous cleaners to solubilize organic surfactants. 2-Butoxyethanol [111-76-2] has achieved some growth at the expense of the lower alkoxyethanols (ie, methoxy and ethoxyethanol) because of 2-butoxyethanol s lower toxicity. 

Further evidence for the Aa11 mechanism was obtained from a solvent kinetic isotope study. The theoretical kinetic isotope effects for intermediates in the three reaction pathways as derived from fractionation factors are indicated in parentheses in Scheme 6.143,144 For the Aa11 mechanism (pathway (iii)) a solvent KIE (/ch2o A d2o) between 0.48 and 0.33 is predicted while both bimolecular processes (pathways (i) and (ii)) would have greater values of between 0.48 and 0.69. Acid-catalysed hydrolysis of ethylene oxide derivatives and acetals, which follow an A1 mechanism, display KIEs in the region of 0.5 or less while normal acid-catalysed ester hydrolyses (AAc2 mechanism) have values between 0.6 and 0.7.145,146... 

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