Other oxygenated solvents

Among the important oxygenated solvents that are not covered above are furan solvents and organic carbonates. Furan solvents of commercial interest include furfuryl alcohol, tetrahydrofuran, and tetrahydrofurfuryl alcohol. They are characterized by strong solvency for some synthetic polymers. Tetrahydrofuran has an evaporation rate between that of acetone and methyl ethyl ketone. Organic carbonate solvents include ethylene and propylene carbonates, diethyl carbonate and dimethyl carbonate, which are good solvents for many polymers. 

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In 5-hydroxy-3-phenyl-l,2,4-oxadiazole (97a) the keto forms (97b, c) predominate due to the proximity of the electronegative oxygens at the sp2 carbon. Of these three tautomers (97c) is favored by IR, UV and NMR spectral data (76BSB35). The tautomer (98b) is more important in the 5-phenyl isomer in solution. Nevertheless the position of tautomeric equilibrium in the two cases is dependent on solvent. For example, in the solid (98b, c) predominates but in acetone and other oxygen solvents (98a) allows for an effective hydrogen bonded dimer (99). 

Comparative absorption spectrophotometry has been used in the studies of lanthanide /J-diketonatc complexes in solids as well as in solutions. The neutral hexacoordinated lanthanide tris diketonate on dissolution in a polar nonaqueous solvent, increased its coordination to eight by accepting two solvent molecules [204]. The addition of water or other oxygenated solvent to Nd(diket)3 in solution resulted in significant changes in the shape and intensity of the band due to 4l9/2 —> 4Gis/2, transition. These changes have been attributed to an increase in coordination number of Nd(III) from 6 to 8 by the coordination of two solvent molecules [238-241]. 

The data presented in Table III show the effect of hostile solvents on the tensile strength of PVC. Although numerous other oxygenated solvents were employed a substantial number of the test specimens essentially disintegrated while attempting to remove them from the test chamber. However, with the data presented, one can easily see that a hostile effect adversely affects both the chemical and physical integrity of the polymer. 

The ability of diethyl ether to extract uranyl nitrate from aqueous solution has been known for a hundred years and was the method chosen by the Manhattan Project to purify the uranium used in the first nuclear chain reactors. This solvent has numerous disadvantages. It is very volatile, very flammable, and toxic, and it requires addition of sodium, aluminum, or calcium nitrate to the aqueous phase to enhance extractions. When solvent extraction was first applied to recovery of uranium and plutonium from irradiated fuel, other oxygenated solvents less volatile than diethyl ether that were first used were methyl isobutyl ketone, dibutyl... 

Other oxygenated solvents Mod/High High Strong acceptors... 

For example, Day-Glo HM Series toners come ia a range of colors suitable for flexographic and gravure inks of the solvent-base type. The Radiant GF Series and Lawter HVT Series are also suitable for this type of apphcation (see Table 2). Generally, these toners are of the formaldehyde—sulfonamide type and requite oxygenated solvents, primarily alcohol—ester blends, for proper solution. For appHcations such as flexographic printing on film, these materials are modified with other resias such as nitrocellulose or polyamides ia the finished ink. 

JSlonhydrocarbon and Oxygenated Solvents. Most kidustrial solvents that are not hydrocarbons are pure chemical compounds. As such, they have sharp boiling pokits and weU-defined properties. Specifications for these solvents focus mosdy on impurities such as water and other contaminants. This also means that a solvent from one manufacturer should perform the same as the same solvent from another manufacturer any differences are probably the result of impurities, stabiLker content, etc, rather than the properties of the overall solvent. 

The given structure shows two molecules of TTA to have reacted with a cobalt ion to form the cobalt-TTA complex, in which the cobalt atom forms a valence bond solid lines) with one, and a coordinate bond (broken lines) with the other, oxygen atom of each TTA molecule. Thus, in the cobalt-TTA complex there is a six-membered ring formed by each TTA molecule with the cobalt atom. Metal chelate complexes of this type have good stability, they are nonpolar and soluble in the organic phase. The usefulness of the chelating extractants in solvent extraction is therefore obvious. 

From the 323 projects in EPA s MTBE Treatment Profiles dataset, 13 projects were identified where MTBE was treated using MPE. Information on the treatment of other oxygenates during these 13 projects is limited no projects reported treating other oxygenates. Most of the 13 MPE projects were full scale (9 projects). Most of the projects (9) used MPE only the remaining four projects supplemented MPE with air sparging (2 projects) and ISCO (2 projects). Short summaries for two projects, MPE at Service Station A, Maryland, and MPE at Sparks Solvent/Fuel Site, Sparks, Nevada, are included at the end of this section. 

Roberts and Laine [25] describe a process for electrochemically transferring oxygen with the scheme shown as Fig. 11. Air or other oxygen-containing gas is drawn into the left side of the vessel. The solution contains an organic solvent such A-methyl pyrrolidine with a supporting electrolyte as tetrabutyl ammonium tetrafluroborate. The carrier, one of the two Schiflf bases shown as Fig. 12, is dissolved to about 3 volume percent. 

Further development in the area of alternate value-added products for improving economics included other oxygenated sulfur compounds [246,247], This invention included alkylated 2-(2-hydroxyphenyl) benzenesulfinic acid and 2-(2-hydroxyphenyl)-benzenesulfonic acid compounds and compositions which consist essentially of 2-(2-hydroxyphenyl) benzenesulfinic acid, 2-(2-hydroxyphenyl)-benzenesulfonic acid and/or substituted derivatives. The compositions are useful as hydrotropes and are also of use as, or as starting materials for, surfactants, and as starting materials for the synthesis of other useful chemicals such as, polymers and resins, solvents, adhesives, and biocides. 

The reactions in a non-basic aprotic solvent CH2C12 provided solely 10, the product of carbon protonation, while those carried out in an acidic protic solvent HFIP give exclusively 8K, the product of oxygen protonation. The equilibrium protonation may be favored in a protic solvent having abundant protons available. In other basic solvents, the proton donor involved in the reaction should be the conjugate acid of the solvent, and many factors may delicately control the selectivity of the reaction. 

In silicate melts and other nonprotonated solvents, the Bronsted-Lowry equation is not applicable and is conveniently replaced by the Lux-Flood acid-base definition (Lux, 1939 Flood and Forland, 1947), according to which free oxygen 0 replaces A basic oxide is one capable of furnishing oxygen ions, and an acidic oxide is one that associates oxygen ions ... 

Isopropyl alcohol production in 1950 exceeded 800,000,000 pounds, all made from petroleum. This alcohol is used mainly as a raw material for the production of acetone and also as a solvent. Acetone is made by the catalytic high temperature dehydrogenation or air oxidation of isopropyl alcohol. A much smaller part of the total acetone supply comes from fermentation and from hydrocarbon oxidation. Like isopropyl alcohol, part of the consumption is for solvent uses, but most serves as a raw material for other oxygenated compounds. 

Ethyl alcohol has been made by the hydration of ethylene (9) since 1930. Like isopropyl alcohol, part of the output is used as a solvent, but most is converted to other oxygenated chemicals. Its most important raw material use is conversion to acetaldehyde by catalytic air oxidation. Acetaldehyde, in turn, is the raw material source of acetic acid, acetic anhydride, pentaerythritol, synthetic n-butyl alcohol (via aldol condensation), butyraldehyde, and other products. Butyraldehyde is the source of butyric acid, polyvinyl butyral resin, and 2-ethylhexanol (octyl alcohol). The last-named eight-carbon alcohol is based on the aldol condensation of butyraldehyde and is used to make the important plasticizer di-2-ethylhexyl phthalate. A few examples of the important reactions of acetaldehyde are as follows ... 

These values have been discussed in some detail to indicate that care is required to take account of the differences in solvents for measurements. They illustrate, nevertheless that a good framework of stabilities of benzyl-related carbocations exists. Other (oxygen-substituted) benzylic cations for which pAR measurements have been reported are discussed below (p. 57-63). 

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