Aromatic liquids

The usual directive influences are not operative in this and similar reactions for ortho - para substitution occurs (this may be modified by steric hindrance) irrespective of the nature of R in the aromatic liquid CsHjR, e.g. phenyldlazo hydroxide and nitrobenzene yield 4-nitrodiphenyl this supports the assumption that neutral free radicals are formed. 

VV -values for bromoform and pyrrole, acidic liquids, against poly(vinyl chloride), an acidic polymer, and dimethyl sulfoxide, a predominantly basic liquid, against polyfmethyl methacrylate), a basic polymer, but large values for the acidic liquids against PMMA and the basic liquid against PVC. 2-Iodoethanol, a bifunctional liquid, showed appreciable -values with both polymers. Despite these results in line with expectations, other results based on wettability measurements are not so clear-cut. For example, Vrbanac [94] found significant apparent acid-base interactions of various aromatic liquids against poly(ethylene), presumably a neutral substrate. 

Methyl-l-hexanone-3, C-HjjO, is found naturally in pennyroyal oil, and is obtained by the decomposition of pulegone. It is an aromatic liquid having the following characters —... 

Ethylbenzene (EB) is a colorless aromatic liquid with a boiling point of 136.2°C, very close to that of p-xylene. This complicates separating it from the Cg aromatic equilibrium mixture obtained from catalytic reforming processes. (See Chapter 2 for separation of Cg aromatics). Ethylbenzene obtained from this source, however, is small compared to the synthetic route. 

A procedure similar to that given below for wholly aromatic liquid crystalline polyesters can be used (see Section 2.4.4.2). The inherent viscosity of the resulting polymers were ca. 0.6 dL/g (0.5 g/dL in phenol-o-dichlorobenzene at... 

Weathering tests, 245 Wholly aromatic liquid crystalline polyesters, degradation of, 38 Wholly aromatic polyamides, 136-137, 139 synthesis of, 184-189 Wholly aromatic polyesters, 25-26, 32 copolymerization and, 35 synthesis of, 71-72... 

The performance of clay materials (Halloysite, Pyrophyllite, Montmorillonite K-30) in the degradation of polystyrene (PS) was investigated in this study. The catalysts showed good catalytic activity for the degradation of PS with high selectivity to aromatics liquids. Styrene is the major product, and ethylbenzene is the second most abundant one in the liquid product. 

Toluene Toluene (C6H5-CH3) is a nonpolar aromatic liquid. It is flammable and has a density of 0.87 g/mL, and thus would be the top layer in the separatory funnel with water. It is only slightly soluble in water (0.47 g/L). Its acute toxicity is low. 

Benzene a colorless aromatic liquid hydrocarbon (CeHs). 

Isopropyl acetate org chem CH3C00CH(CH3)2 A colorless, aromatic liquid with a boiling point of 89.4°C used as a solvent and for paints and printing inks. T-so pro-pol as-3,tat ... 

Studies have shown that the electron mobility in aromatic liquids changes upon the application of external pressure but becomes constant above 2 kbar. At low pressures, the electron is trapped in a cavity as discussed for alkanes in Sec. 6.2. Increasing the pressure causes the equilibria... 

CCOOC3Ha)2 mw 146.14, col, unstable aromatic liquid combustible but not flammable sp gr 1-079 at 20/4° (Lange), 1.09 at 20/20° (Ref 3), fr P -40.6°, bp 185-4-186° fl p 168°F v si isol in w with gradual deoompn miscible with ale, eth, eth acetate and other common org solvents. Can be prepd by standard esterification procedure using ethanol oxalic acid. The final purification, however calls for specific technique and equipment (Ref 3). Used as solvent for cellulose esters ethers and for synthetic resins also for radio tube cathode fixing lacquers, pharmaceuticals, etc... 

The HLB temperature was found to be the most important factor in the formation of stable emulsions. In each case, w/o HIPEs [9,11,80] would only form at temperatures above the HLB temperature of the systems, while o/w HIPEs [14] formed below the PIT. The nature of the oil phase was also found to be of importance to the formation of stable w/o HIPEs [11] aromatic liquids, for example, did not produce highly concentrated emulsions. With aliphatic oils, the stability was observed to vary with chemical nature. This was due to the different HLB temperatures for each liquid. 

These conceptions were useful in synthesis of a variety of aliphatic and mixed (aliphatic-aromatic) liquid diamines with a lower reactivity 1041... 

In general terms, as the molecular weight of the feedstock is increased, similar operating conditions of hydrogasification lead to decreasing hydrocarbon gas yields, increasing yields of aromatic liquids, with carbon also appearing as a product. 

Nitro-DisplacementPolymerization. The facile nucleophilic displacement of a nitro group on a phthalimide by an oxyanion has been used to prepare polyetherimides by heating bisphenoxides with bisnitrophthalimides (91). For example with 4,4/-dinitro monomers, a polymer with the Ultem backbone is prepared as follows (92). Because of the high reactivity of the nitro phthalimides, the polymerization can be carried out at temperatures below 75°C. Relative reactivities are nitro compounds over halogens, A/-aryl imides over IV-alkyl imides, and 3-substituents over 4-substituents. Solvents are usually dipolar aprotic liquids such as dimethyl sulfoxide, and sometimes an aromatic liquid is used, in addition. 

Liquid insulators are required for circuit breakers, transformers, and some cable applications. Natural hydrocarbon mineral oils are commonly-used, as well as chlorinated aromatic liquids (desirable because of nonflammability). For high-temperature situations, silicone fluids may be used. Permittivities range between 2 and 7. Insulating liquids function both as electrical insulators and heat-transfer media. See also Dielectric Theory. 

Crystallization. Low temperature fractional crystallization was the first and for many years the only commercial technique for separating PX from mixed xylenes. As shown in Table 2, PX has a much higher freezing point than the other xylene isomers. Thus, upon cooling, a pure solid phase of PX crystallizes first. Eventually, upon further cooling, a temperature is reached where solid crystals of another isomer also form. This is called the eutectic point. PX crystals usually form at about —4° C and the PX-MX eutectic is reached at about —68° C. In commercial practice, PX crystallization is carried out at a temperature just above the eutectic point. At all temperatures above the eutectic point, PX is still soluble in the remaining Cg aromatics liquid solution,... 

Similar to conventional QSAR, a speciLc LSER equation is limited for a speciLc set of compounds. In subsequent studies, Kamlet et al. (1987) found that dependency of solubility in water on polarity/polarizability is different for aromatic liquids than for aliphatic liquids. For liquid aromatic compounds with a hydrogen-bond acceptor and without hydrogen-bond donors, the LSER is... 

The second step is carried out by adding a 15-40% aqueous solution of sodium hydroxide dropwise to a well-stirred mixture of the cold dia-zonium salt solution and the aromatic liquid until a slight excess of alkali is present. This procedure avoids the isolation of the unstable, explosive diazohydroxides of Bamberger,1 which are formed from the diazonium salt and the alkali. The diazohydroxide is extracted by the aromatic liquid as it is formed. The biaryl reaction takes place in the organic liquid and is complete when evolution of nitrogen ceases. In the example given, 4-bromobiphenyl is obtained in 35-46% yield. 

A variation in the procedure for certain amines is to add the diazonium salt to sodium hydroxide in an amount sufficient to form the sodium diazotate. The biaryl compound is formed when the aqueous solution of the diazotate is stirred with an aromatic liquid.4... 

In place of sodium hydroxide, sodium acetate may be added to the mixture of diazonium salt solution and the aromatic liquid.6 Another variation, introduced by Hodgson and Marsden,6 consists in converting the aryldiazonium chloride to a stabilized diazonium salt by treatment wi,th naphthalene-l-sulfonic acid, naphthalene-1,5-disulfonic acid, or zinc chloride the dried salt is then suspended in an aromatic liquid and treated with sodium acetate and acetic anhydride. 

The nitrosation is carried out by passing nitrous fumes into an ice-cold solution or suspension of the acetylamine in acetic acid and acetic anhydride, or by adding a solution of nitrosyl chloride to the acetylamine and sodium acetate in acetic acid. The nitroso derivative is precipitated by pouring the solution into ice water and is extracted by the aromatic liquid or filtered and added to the liquid with which it reacts. In the example given, 3-nitrobiphenyl is obtained from m-nitroacetanilide in 83% yield. 

The reaction of the aryldiazo acetates with aromatic compounds to give biaryls was utilized first by Ktlhling,2 who treated a suspension of the potassium diazotate, RN2OK, in the aromatic liquid with acetyl chloride. 

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