Toluene Mixtures

Though toluene alone is not known to induce SAB, an occupational study in Finland has reported associations when pregnant women were exposed to mixtures of toluene with other organic solvents, including hydrophilic and lipophilic speciesJ23l These studies point out difficulties encountered where adverse health associations are made without considering mixture effects. 

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Acetone, methyl ethyl ketone, methyl isobutyl ketone, dimethylformamide, ethyl acetate, and tetrahydrofuran are solvents for vinyhdene chloride polymers used in lacquer coatings methyl ethyl ketone and tetrahydrofuran are most extensively employed. Toluene is used as a diluent for either. Lacquers prepared at 10—20 wt % polymer sohds in a solvent blend of two parts ketone and one part toluene have a viscosity of 20—1000 mPa-s (=cP). Lacquers can be prepared from polymers of very high vinyhdene chloride content in tetrahydrofuran—toluene mixtures and stored at room temperature. Methyl ethyl ketone lacquers must be prepared and maintained at 60—70°C or the lacquer forms a sohd gel. It is critical in the manufacture of polymers for a lacquer apphcation to maintain a fairly narrow compositional distribution in the polymer to achieve good dissolution properties. 

Let us consider the separation of polymethylmethacrylate (PMMA) on a nonmodified silica column as an example. In THE (medium polar eluent) the PMMA eludes in size exclusion mode because the dipoles of the methylmethacrylate (MMA) are masked by the dipoles of the THE. Using the nonpolar toluene as the eluent on the same column, the separation is governed by adsorption because the dipoles of the carbonyl group in the PMMA will interact with the dipoles on the surface of the stationary phase. The separation of PMMA in the critical mode of adsorption can be achieved by selecting an appropriate THF/toluene mixture as the eluent. In this case all PMMA samples... 

Reduction of fullerenes to fullerides — Reversible electrochemical reduction of Ceo in anhydrous dimethylformamide/toluene mixtures at low temperatures leads to the air-sensitive coloured anions Qo" , ( = 1-6). The successive mid-point reduction potentials, 1/2, at -60°C are -0.82, -1.26, -1.82, -2.33, —2.89 and —3.34 V, respectively. Liquid NH3 solutions can also be used. " Ceo is thus a very strong oxidizing agent, its first reduction potential being at least 1 V more positive than those of polycyclic aromatic hydrocarbons. C70 can also be reversibly reduced and various ions up to... 

Kalir and Szara obtained l,3-bis(a-chloropropionyl)indole (140) by the action of a 20% excess of a-chloropropionyl chloride on indole magnesium bromide in an ether-toluene mixture. On the other hand, Ganellin and Ridley obtained 3-(o -chloropropionyl)indole (141) by the action of a 10% excess of a-chloropropionyl chloride on indole magnesium iodide in anisole. -... 

Example 8-5 Boiling Point Curve and Equilibriiun Diagram for Benzene-Toluene Mixture... 

Figure 8-19. X-y diagram for benzene in benzene-toluene mixture at 760 mm Hg total pressure, Example 8-5.

Figure 8-20. Boiling point diagram for benzene-toluene mixture using K values, total pressure 760 mm Hg for Example 8-6.

A benzene-toluene mixture is to be separated in a tower packed with 1-in. fieri saddles. The feed is 55.2 mol% (liquid feed, saturated), and an overhead of 90 mol% benzene, and bottoms of not more than 24 mol% benzene is desired. Using the data of Ref. 51 plotted in Figure 9-98, determine the number of transfer units in the rectifying and stripping sections using a reflux ratio (reflux to product, L/B) = 1.35. 

Prepare a benzene-toluene mixture by placing 0.05 mL of each liquid in a 25 mL graduated flask and making up to the mark with methanol. Take 1.5 mL of this solution, place in a lOmL graduated flask and dilute to the mark with methanol this solution contains benzene at the same concentration as solution 5, and toluene at the same concentration as solution 5. Measure the absorbances of this solution at the two wavelengths selected for the Beer s Law plots of both benzene and toluene. Then use the procedure detailed in Section 17.48 to evaluate the composition of the solution and compare the result with that calculated from the amounts of benzene and toluene taken. 

Cycloheptatriene containing 9% toluene is available from the Shell Chemical Company, New York. Less pure cycloheptatriene, obtained by pyrolysis of bicycloheptadiene followed by a crude distillation, has been used successfully in this preparation. The quantity of the tropilidene/toluene mixture is adjusted in accord with its purity as estimated by vapor-phase chromatography on didecyl phthalate. 

In the presence of decane and a decane-toluene mixture, C16 HAS gives more stable foams than C16 AS. However, such is not the case for the corresponding C18 compounds. In the presence of the decane-toluene mixture, C18 AS and C18 HAS produce foams of approximately equal stability. In the presence of decane, C18 HAS produces a more stable foam than C18 AS. The reason for the differences in behavior between the C16 and C18 compounds is not understood. However, the cause may be related to the hydrophobe carbon number and the oil phase polarity. 

The results in Table 22 for a series of one atmosphere 75 °C foaming experiments indicate the effect of hydrophobe carbon number. The foam stability of C18 AS is greater than that of C16 AS in the absence of an oil phase, in the presence of decane, and in the presence of the decane-toluene mixture. The foam stability of C18 HAS is greater than that of C16 HAS in the absence of an oil phase. In the presence of decane and in the presence of the decane-toluene mixture, the foam stability of the C18 HAS is, if anything, slightly less than that of C16 HAS. This may have been the result of partitioning effects. 

ABA type poly(hydroxyethyl methacrylate) (HEMA) and PDMS copolymers were synthesized by the coupling reactions of preformed a,co-isocyanate terminated PDMS oligomers and amine-terminated HEMA macromonomers312). Polymerization reactions were conducted in DMF solution at 0 °C. Products were purified by precipitation in diethyl ether to remove unreacted PDMS oligomers. After dissolving in DMF/toluene mixture, copolymers were reprecipitated in methanol/water mixture to remove unreacted HEMA oligomers. Microphase separated structures were observed under transmission electron microscope, using osmium tetroxide stained thin copolymer films. 

Mixtures of isomers, such as o-, m- and / -xylene mixtures, and adjacent members of homologous series, such as n-hexane-n-heptane and benzene-toluene mixtures, give close to ideal liquid-phase behavior. For this case, yt = 1, and Equation 4.28 simplifies to ... 

Water-soluble carbonyls are relatively rare. A route to such a species involves reaction at room temperature of the sulfonated phosphine P(PhS03)33- as its water-soluble Na+ salt with Co2(CO)8 in a two-phase water/toluene mixture, whereupon the product forms in the aqueous phase in high yield.85... 

Conditions for the safe preparation of the diisocyanate from adipoyl chloride and sodium azide in acetonitrile-toluene mixtures were established. 

Mixtures with nitrobenzene were formerly used as liquid high explosives, with addition of carbon disulfide to lower the freezing point, but high sensitivity to mechanical stimulus was disadvantageous [1], Dining the recovery of acids from nitration of toluene, mixtures of the oxide with nitrotoluene or dinitrotoluene may... 

The situation may be further complicated by the presence of different polymorphs for tris(l-pyrrolidine-dithiocarbamato)iron(III) two solvent-free modifications could be characterised. The first one has been crystallised from an ethanol/chloroform solution [14], whereas the second has been isolated from a chloroform/toluene mixture [16]. Both compounds differ in their structural parameters determined at room temperature, where they are both high spin. At lower temperatures the ethanol/chloroform product displays a gradual spin transition [14], whereas the chloroform/toluene form remains high spin down to very low temperature [33]. 

The following values represent the equilibrium conditions in terms of mole fraction of benzene in benzene-toluene mixtures at their boiling-point ... 

PVA-PAcr.Ac. membranes have been tested also for ethanol separation from ethanol/toluene mixture, by using pervaporation technique. The reported data concerning the separation process characteristics are presented in table 8. 

Methanol/toluene mixtures could be separated by pervaporation technique using PVA/PAcr.Ac. blend membranes. Reported data are presented in table 10. 

Fig. 6 Luminescent profile of Au23 cluster before (pink trace) and after (orange trace) phase transfer. Emission of the cluster enhances considerably after phase transfer. Photographs of the aqueous-toluene mixture containing the cluster before and after phase transfer under white light (A and B, respectively) and UV light (C and D, respectively). In C, only the interface is illuminated as the UV radiation is attenuated as the sample was irradiated from the top [15]...

The reduction in the required number of plates as R is increased beyond Rm will tend to reduce the cost of the column. For a column separating a benzene-toluene mixture, for example, where Xf = 0.79, xd = 0.99 and xw = 0.01, the numbers of theoretical plates as given by the McCabe-Thiele method for various values of R are given as follows. The minimum reflux ratio for this case is 0.81. 

A variety of procedures were utilized to analyze this reaction mixture and to characterize a,10-diaminopolystyrene. Thin layer chromatographic analysis using toluene as eluent exhibited three spots with Rf values of 0.85, 0.09, and 0.05 which corresponded to polystyrene, poly(styryl)amine and a,w-diaminopolystyrene (see Figure 1). Pure samples of each of these products were obtained by silica gel column Chromatography of the crude reaction mixture initially using toluene as eluent [for polystyrene and poly(styryl)amine] followed by a methanol/toluene mixture (5/100 v/v) for the diamine. Size-exclusion chromatography could not be used to characterize the diamine since no peak was observed for this material, apparently because of the complication of physical adsorption to the column packing material. Therefore, the dibenzoyl derivative (eq. 5) was prepared and used for most of the analytical characterizations. 

An example of this effect may be seen by considering the data of Schmid and Beut-tenmuller [34] for the degradation of polystyrene in CCl4/toluene mixtures of various... 

Tab. 5.4 Degradation of polystyrene in various CCl4/toluene mixtures.

Moumouzias, G. and Ritzoulis, G. Relative permittivities and refractive indices of propylene carbonate + toluene mixtures from 283.15 K to 313.15 K, J. Chem. Eng. Data, 42(4) 710-713, 1997. 

It is to be mentioned that water-soluble phosphine complexes of rhodium(I), such as [RhCl(TPPMS)3], [RhCl(TPPTS)3], [RhCl(PTA)3], either preformed, or prepared in situ, catalyze the hydrogenation of unsaturated aldehydes at the C=C bond [187, 204, 205]. As an example, at 80 °C and 20 bar H2, in 0.3-3 h cinnamaldehyde and crotonaldehyde were hydrogenated to the corresponding saturated aldehydes with 93 % and 90 % conversion, accompanied with 95.7 % and 95 % selectivity, respectively. Using a water/toluene mixture as reaction medium allowed recycling of the catalyst in the aqueous phase with no loss of activity. 

Tuulmets, A. Nguyen, B. T. Panov, D. Sassian, M. Jarv, J. Kinetics of the Grignard Reaction with Silanes in Diethyl Ether and Ether-Toluene Mixtures. J. Org. Chem. 2003, 68, 9933-9937. 

BINAP core-functionalized dendrimers were synthesized by Fan et al. (36), via condensation of Frechet s polybenzyl ether dendritic wedges to 5,5 -diamino-BINAP (26—28). The various generations of BINAP core-functionalized dendrimers were tested in the ruthenium-catalyzed asymmetric hydrogenation of 2-[p-(2-methyl-propyl)phenyl]acrylic acid in the presence of 80 bar H2 pressure and in a 1 1 (v/v) methanol/toluene mixture. As later generations of the in situ prepared cymeneruthe-nium chloride dendritic catalysts were used, higher activities were observed (TOF values were 6.5, 8.3, and 214 h respectively). Relative to those of the BINAP... 

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