Liquid phenol

If no solid precipitate is obtained but the solution becomes cloudy, a low-melting or liquid phenol is indicated this will, of course, be revealed also by the characteristic phenolic odour. Transfer to a separating-funnel and extract with an equal volume of ether. Separate and dry with anhydrous sodium sulphate. Distil off the ether and identify the residue. 

Because phenols are weak acids, they can be freed from neutral impurities by dissolution in aqueous N sodium hydroxide and extraction with a solvent such as diethyl ether, or by steam distillation to remove the non-acidic material. The phenol is recovered by acidification of the aqueous phase with 2N sulfuric acid, and either extracted with ether or steam distilled. In the second case the phenol is extracted from the steam distillate after saturating it with sodium chloride (salting out). A solvent is necessary when large quantities of liquid phenols are purified. The phenol is fractionated by distillation under reduced pressure, preferably in an atmosphere of nitrogen to minimise oxidation. Solid phenols can be crystallised from toluene, petroleum ether or a mixture of these solvents, and can be sublimed under vacuum. Purification can also be effected by fractional crystallisation or zone refining. For further purification of phenols via their acetyl or benzoyl derivatives (vide supra). 

One of the first applications of the Redux process was in construction of structural aluminum parts for the de Havilland bomber Sea Hornet produced during World War II ([198], pp. 80-81 [202,203]). In the original fonn, it consisted of a two-part adhesive including a low viscosity liquid phenolic known... 

PRF adhesives in which a liquid phenol-resorcinol-formaldehyde adhesive and a powder or liquid hardener are used are currently the most commonly used industrially. Pure resorcinol-formaldehyde (RF) adhesives were used extensively... 

Phenol is a colorless-to-white solid when pure however, the commercial product, which contains some water, is a liquid. Phenol has a distinct odor that is sickeningly sweet and tarry. Most people begin to smell phenol in air at about 40 parts of phenol per billion parts of air (ppb), and begin to smell phenol in water at about 1-8 parts of phenol per million parts of water (ppm ... 

Application of phenol to the skin can be lethal. Death occurred within 10 minutes after 25% of an individual s body surface was exposed to liquid phenol (Griffiths 1973). The cause of death was reported to be cardiac and respiratory depression. In another report, an individual died after being painted with a brush that had been soaked in a solution of phenol and thoroughly washed before use (Lewin and Cleary 1982). In neither case was the dose known with sufficient accuracy to establish a lethal dose. 

Hemoglobinuria and hematin casts in the distal convoluted tubules and tubular lumens located in the medulla and papilla were reported in rats after a single dermal exposure to 107.1 mg/kg liquid phenol (Conning and Hayes 1970). These phenomena are probably related to red blood cell lysis and increased glomerular filtration of hemoglobin. Hemoglobinuria is characteristic of lethal or near-lethal exposures by the dermal route. 

Muscle tremors and convulsions are characteristic effects of acute dermal phenol toxicity in laboratory animals. Tremors that developed into convulsions and prostration were reported in rats exposed to 107.1 mg/kg liquid phenol application surface areas were not reported (Conning and Hayes 1970). In pigs, application of 500 mg/kg over 35-40% of the body surface (0.44 mg/cm2/kg) resulted in muscular tremors in the head region within 3-5 minutes of exposure (Pullin et al. 1978). This was followed by dilation of the pupils, loss of coordination, and excess salivation and nasal discharge within 5 minutes of exposure. It was followed by convulsions, coma, and death 5-7 minutes after exposure in two of three pigs. Direct application of a dose of 37.5 mg/kg phenol to the inner ear resulted in a reduced threshold for auditory brainstem response (Schmidt et al. 1990). 

Uses. The major applications of phenol are phenolic resins, Bisphenol A, and caprolactam. The reaction of phenol with formaldehyde gives liquid phenolic resins (used extensively as the adhesive in plywood) and solid resins (used as engineering plastics in electrical applications). In powder form, the phenolic resin can be molded easily and are completely nonconductive. These phenolic resins or plastics can be found in panel boards, switchgears, and telephone assemblies. The agitator in your washing machine is probably a phenolic resin. 

Phenols are a major chemical lump present in coal liquids. Phenols have basically one or more aromatic ring structures with alkyl substituents. Methyl, ethyl and propyl are the most common alkyl substituents. The smallest specie is the one with a hydroxyl group attached to a benzene ring. Addition of a methyl group produces three isomers - o-, m-, and p-cresols. It appears that all three are present in more or less same proportion. The number of possible isomers increases as the possible number and size of alkyl substituents increases. It is expected that higher... 

The addition of a surfactant to liquid phenol resol oligomers affects the dispersity of the gas bubbles in the resin droplets and thus can increase the yield of hollow microspheres33,34 ... 

Nowotny, 1967). Therefore, the ether extraction method was developed for the extraction of R-LPS (Galanos et al 1969). This method uses a monophasic solution consisting of liquid phenol, chloroform and petroleum ether (PCP). In such a solution, R-LPS is completely soluble, but S-LPS, proteins, nucleic acids and polysaccharides are insoluble and can be excluded from the extracts. The ratio of phenol, chloroform and petroleum ether in PCP is normally 2 5 8 (v/v/v), but 5 5 8 (v/v/v) also works (Helander et al 1992). The following is a brief protocol for the ether extraction of LPS ... 

The hydrate and phenol clathrate equilibrium data of the water-carbon dioxide, phenol-carbon dioxide, and water-phenol-carbon dioxide systems are presented in Table 1 and depicted in Figure 2. In order to establish the validity of the experimental apparatus and procedure the hydrate dissociation pressures of carbon dioxide measured in this work were compared with the data available in the literature (Deaton and Frost [7], Adisasmito et al. [8]) and found that both were in good agreement. For the phenol-carbon dioxide clathrate equilibrium results, as seen in Figure 2, the dramatic increase of the dissociation pressures in the vicinity of 319.0 K was observed. It was also found in the previous study (Kang et al. [9]) that the experimental phenol-rich liquid-phenol clathrate-vapor (Lp-C-V) equilibrium line of the binary phenol-carbon dioxide system could be well extended to the phenol clathrate-solid phenol-vapor (C-Sp-V) equilibrium line (Nikitin and Kovalskaya [10]). It is thus interesting to note that a quadruple point at which four individual phases of phenol-rich liquid, phenol clathrate, solid... 

For the ternary water-phenol-carbon dioxide system, several interesting phenomena were observed. As shown in Figure 2, the four-phase, water-rich liquid-phenol-rich liquid-phenol clathrate-vapor (Lw-Lp-C-V), dissociation pressures were measured at several temperatures near 293.0 K. Like above the phenol-carbon dioxide clathrate equilibrium results, the dramatic increase of the four-phase dissociation pressures was observed in a vicinity of 293.0 K. One of the most interesting results observed in this work is that a quintuple point at which the five phases of water-rich liquid, phenol-rich liquid, carbon dioxide-rich liquid, phenol clathrate, and vapor coexist in equilibrium was carefully measured and found to be 293.7 K and 57.2 bar. 

Choice of the Lignin Modification Reaction. The phenolysis reaction was selected as a means of modifying the structure and reactivity of the ammonium lignin sulfonate for three main practical reasons. First, because this lignin derivative is soluble in (and will ultimately be used in conjunction with) liquid phenol itself second, because unreacted phenol, unlike other reaction solvents, would not have to be removed from the phenolated product after reaction and before conversion to the adhesive resin and third, because lignins and carbohydrates are known to react with phenols under acidic conditions (6,7). 

Novolaks were prepared using a phenol-to-formaldehyde molar ratio of 4 1 with 5 mole percent of H2SO4 added as a catalyst. Typically, 47 g liquid phenol (91.7% assay), 3 g paraformaldehyde, and 30 mL water plus the required acid catalyst were added to a three-neck, 250-mL round bottom flask. The flask was fitted with a reflux condenser and stirrer. The mixture was refluxed for 2 to 4 hours with the oil bath at 115 °C then, the mixture was neutralized with 50% (w/w) NaOH and the excess phenol removed by steam distillation for 5 to 6 hours. The remaining viscous oily residue was washed repeatedly with boiling water. A novolak with the P/N fraction was prepared as described above with 1 1 by volume phenol and P/N fraction and half of the amount of formaldehyde. Initial wood-gluing testing with this novolak indicates wood failure rather than glueline failure. 

SAFETY PROFILE Poison by ingestion, subcutaneous, intravenous, and intraperitoneal routes. Moderately toxic by intramuscular route. Can cause liver and kidney damage. The liquid phenol reacts violendy with KOH. Product of reaction with chlorosulfuric acid decomposes violendy at 24°C. When heated to decomposition it emits toxic fumes of NOx. See also NITRO COMPOUNDS OF AROMATIC HYDROCARBONS. 

The reaction between benzyl chloride and sodium phenoxide follows second-order kinetics in a variety of solvents the nature of the products, however, v tries considerably. (a) In dimethylformamide, dioxane, or tetrahydrofuran, reaction yields only benzyl phenyl ether. Show in detail the mechanism of this reaction. To what general class does it belong (b) In aqueous solution, the yield of ether is cut in half, and there is obtained, in addition, o- and p-benzylphenol. Show in detail the mechanism by which the latter products are formed. To what general class (or classes) does the reaction belong (c) What is a possible explanation for the difference between (a) and (b) Hint See Sec. 1.21.) (d) In methanol or ethanol, reaction occurs as in (a) in liquid phenol or 2,2,2-trifluoroethanol, reaction is as in (b). How can you account for these differences ... 

An optimized blend of liquid phenolic antioxidant and liquid aromatic amine antioxidant with a small amount of a phosphite stabilizer. This blend was specifically developed for use as a heat and color stabilizer for polyols used for making flexible polyurethane foam. 

Properties Colorless, yellowish, or pinkish liquid phenolic odor. D 1.030-1.047, wt/gal 8.66-8.68 lb, flash p approximately 180F (82C), mp 11-35C, bp 191-203C. Soluble in alcohol, glycol, dilute alkalies, and water. 

Properties Dark-red liquid phenolic odor, free of methylamine. D 1.010 (25/25C), refr index 1.530 (25C), distillation range 80-130C (2 mm Hg), water content (Karl Fischer) 0.5%. Soluble in organic solvents moderately soluble in water. 

Properties Straw-colored liquid phenolic odor. D 0.94 (20/20C), flash p 325F (162.7C), boiling range 310-335C. Soluble in water. Combustible. 

Properties Compressed gas, easily liquefied, ethereal odor, usually handled as liquid. Phenol is added as a polymerization inhibitor. D 0.9121 (liquid at 20/ 20C), bp -13.9C, fp -159.7C, vap press 2300 mm Hg (20C), flash p-108F (-77C), autoign temp 882F (472C). Slightly soluble in water soluble in alcohol and ether. 

Ahronson presented a glycerinated phenol formulation 88% liquid phenol is solubilized in anhydrous glycerol (glycerin) and a few drops of alcohol. This highly concentrated formula, used without occlusion, produces a peel that is not as deep as a peel with Baker-Gordon solution. 

Two Baker solutions are described. The first contains liquid phenol USP 5 cm, distilled water 4 cm, croton oil 3 drops and septisol 5 drops. The second contains liquid phenol USP 3 cm, distilled water 2 cm, croton oil 3 drops and septisol 8 drops. The water determines the concentration, which is variable. Baker s solution has to be stirred constantly, as it is not stable and separates into layers if left to rest. 

Liquid phenol Liquid phenol Liquid phenol... 

Stone performed a histological study of the depth of penetration of various phenol formulas the Gordon-Baker formula at 48.5% phenol, the Verner-Dickinson formula at 67% and liquid phenol at 88%. The results, in keeping with the principles set out above, show that Baker s formula penetrates twice as deeply as Verner s and four times as deeply as liquid phenol at 88%. Although phenol is absorbed rapidly by skin tissue, only a part of it will gradually reach the innermost regions, as the skin proteins flocculate almost immediately, and this creates a physical catchment area for the phenol as well as a natural dam that stops it penetrating the deeper layers too quickly. 

All this - and even the fact that phenol was considered highly toxic by inhalation - did not stop Bethene and Court" suggesting inhalation of liquid phenol fumes to treat whooping cough in 1954. The plasma concentrations reached were far higher than those described by Litton during fuU-face peels. 

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