Biphenyl solvent

Figure 3.17 Birefringence as a function of the eigenvalue of the velocity gradient tensor, G, for planar flows generated in a four-roll mill, for dilute solutions of polystyrenes of three different molecular weights in polychlorinated biphenyl solvent. Here G is the strain rate and a the flow type parameter. For planar extension, a — 1 and G = is the extension rate for simple shear, a = 0 and G = y is the shear rate. The different symbols correspond to a values of 1.0 (0)> 0.8 (A), 0.5 (-1-), and 0.25 (diamonds). The curves are theoretical predictions from the FENE dumbbell model, including conformation-dependent drag (discussed in Section 3.6.2.2.2). (From Fuller and Leal 1980, reprinted with permission from Steinkopff Publishers.)...

Biphenyl, butenylated 1,1 -Biphenyl (1-methylethyl) Bis (methylethyl)-1,1 -biphenyl solvent, tissue drying Tetramethylsilane solvent, tobacco sprays SD alcohol 4 solvent, toilet waters... 

In subsequent work by Britt et al. [37], the influence of substituents on the pyrolysis mechanism of PPE in biphenyl solvent at moderate temperature (345°C) was considered. Naturally occurring methoxy and hydroxy substituents were located at either phenyl ring as depicted in Figure 7.4. It was found that the radical mechaifism... 

The performance of SCWO for waste treatment has been demonstrated (15,16). In these studies, a broad number of refractory materials such as chlorinated solvents, polychlorinated biphenyls (PCBs), and pesticides were studied as a function of process parameters (17). The success of these early studies led to pilot studies which showed that chlorinated hydrocarbons, including 1,1,1-trichloroethane /7/-T5-6y,(9-chlorotoluene [95-49-8] and hexachlorocyclohexane, could be destroyed to greater than 99.99997, 99.998, and 99.9993%, respectively. In addition, no traces of organic material could be detected in the gaseous phase, which consisted of carbon dioxide and unreacted oxygen. The pilot unit had a capacity of 3 L/min of Hquid effluent and was operated for a maximum of 24 h. 

Solvent extraction followed by gas chromatographic analysis is used to determine paraffin wax antioxidants (qv), ie, butylated hydroxyanisole and butylated hydroxytoluene and other volatile materials. Trace amounts of chlorinated organic compounds, eg, polychlorinated biphenyls, can be deterrnined by using a gas chromatograph with an electron-capture detector (22). 

Pure biphenyl is a white crystalline soHd that separates from solvents as plates or monoclinic prismatic crystals. Commercial samples are often slightly yellow or tan in color. Similady, pure terphenyls are white crystalline soHds whereas commercial grades are somewhat yellow or tan. Physical and chemical constants for biphenyl and the three isomeric terphenyls are given in Tables 2 and 3, respectively. 

Biphenyl, terphenyl, and their alkyl or hydrogenated derivatives generally serve markets where price and performance, rather than composition, is the customer s primary concern. Performance standards for heat-transfer appHcations are usually set by the fluid suppHer. The biphenyl—diphenyl oxide eutectic (26.5% biphenyl, 73.5% DPO) represents a special case. This composition has become a widely recogni2ed standard vapor-phase heat-transfer medium. It is sold throughout the world under various trademarks. In the United States, Dow (Dowtherm A) and Monsanto (Therminol VP-1) are the primary suppHers. Alkylated biphenyls and partially hydrogenated terphenyls serving the dielectric and carbonless copy paper dye solvent markets likewise are sold primarily on the basis of price and performance characteristics jointly agreed on by producer and user. 

Short-chain alkylated biphenyls are the principal biphenyl derivatives in commercial use. They are generally produced by Hquid-phase Friedel-Crafts alkylation of biphenyl with ethylene, propylene, or mixed butenes. A series of mixed ethylated biphenyl heat-transfer fluids (trademarked Therm S-600, 700, 800) is marketed by Nippon Steel. A mixed diethylbenzene—ethylbiphenyl heat-transfer fluid is also available from Dow (63). Monoisopropylbiphenyl [25640-78-2] largely as a mixture of meta- and para-isomers is produced by Koch Chemical Co. Monoisopropylbiphenyl (MIPB) was selected by Westinghouse (64,65) as a PCB replacement in capacitors and this is its primary appHcation today. For a time MIPB was also employed as a PCB replacement in pressure sensitive copy paper, but this outlet has since given way to other dye solvents. A similar product consisting of a mixture of j -butylbiphenyl isomers [38784-93-9] (66) is currently the favored dye solvent for pressure sensitive copy paper (67) manufactured in the United States. 

Special additives are often included in a carrier formulation to provide specific properties such as foam control, stabiUty, and fiber lubrication during dyeing. Most important are the solvents used to solubilize the soHd carrier-active chemicals. These often contribute to the general carrier activity of the finished product. For example, chlorinated benzenes and aromatic esters are good solvents for biphenyls and phenylphenols. Flammable compounds (flash point below 60°C) should be avoided. 

Extraction, employs a liquid solvent to remove certain compounds from another liquid using the preferential solubility of these solutes in the MSA. For instance, wash oils can be used to remove phenols mid polychlorinated biphenyls (PCBs) from die aqueous wastes of synthetic-fuel plants and chlorinated hydrocarbons from organic wastewater. 

Reaction of 3-(3-bromopropy])-3-(4-biphenyl)perhydropyrido[l,2-c][l,4]oxazine with AgN03 in a boiling solvent yielded 3-[(4-biphenyl)per-hydropyrido[l,2-c][],4]oxazin-3-yl]propyl nitrate (00MI9). 

Figure 13.2 MDGC-ECD chromatograms of PCB fractions from sediment samples, demonstrating the separation of the enantiomers of (a) PCB 95, (b) PCB 132, and (c) PCB 149 non-labelled peaks were not identified. Reprinted from Journal of Chromatography, A 723, A. Glausch et al, Enantioselective analysis of chiral polyclilorinated biphenyls in sediment samples by multidimensional gas cliromatography-electi on-capture detection after steam distillation-solvent exti action and sulfur removal , pp. 399-404, copyright 1996, with permission from Elsevier Science.

Thermolysis of 2,2 -bis(azidomethyl)biphenyl (33) in an inert solvent produces a mixture of phenanthridine (21 %) and 5//-dibenz[c,e]azepine (29% bp 138—140°C/0.08 Torr). The yield of dibenzazepine is increased to 57% by carrying out the thermolysis under reduced pressure over glass beads.86 The mechanism of this unique reaction has been discussed. 

A solution of 2 -(bromomethyl)biphenyl-2-carbaldehyde (45 1 g 3.6 mmol) and 25 % aq NH3 (20 mL) in EtOH (100 mL) was heated under reflux for 5 h. The mixture was cooled and stirred for 15 min with 10% aq NaOH (20 mL). The basic solution was extracted with CH2C12, the extract dried, and the solvent evaporated to give the product as an oil which was purified by flash chromatography (silica gel, Et20/ hexane) yield 0.667 g (95%) mp 84-85 C... 

A solution of compound 7 or 8 (100 mmol) in Ph,0/biphenyl (150 mL, 3 1) or in collidine (150mL) was heated under reflux for l-2h. When Ph20/biphenyl was used the reaction mixture was treated with petroleum ether/acetonc (500 mL, 1 1) when collidine was used the solvent was distilled off in vacuo and the residue was triturated with petroleum ether/acetone (100 mL, 1 1). The resulting precipitate was filtered off and recrystallized (2-hydroxyethyl methyl ether/charcoal). 

Several dibenzo[e,g][l,4]diazocines 4 have been prepared by the condensation of biphenyl-2,2 -diamine derivatives 3 with 1,2-diones. The reaction proceeds upon simply melting the two components together, or byluxing in a high-boiling solvent. 

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