Physical properties phenols

Physical properties. All solid except m -cresol, CH3CJH4OH, which is a liquid. All colourless when pure, but frequently slightly coloured due to atmospheric oxidation. All have in varying degrees a characteristic odour of carbolic acid. Phenol, the cresols and resorcinol have a caustic action on the skin. 

Physical Properties. Both solids, freely soluble in hot water, sparingly in cold water. o-Nitrophcnol, bright yellow, volatile in steam, odour resembling both that of phenol and of nitrobenzene />-m trophenol, colourless when pure, non-volatile in steam, odourless. 

The melting points of the derivatives of a number of selected phenols are collected in Table IV, 114, The physical properties of a number of enols are given in Table IV,114A,... 

The physical properties of some representative phenols are collected in Appendix 1... 

Comparison of Physical Properties of an Arene, a Phenol, and an Aryl Halide... 

TABLE C Selected Physical Properties of Representative Alcohols Ethers and Phenols ... 

Catalysis is usually accompHshed through the use of tertiary amines such as triethylenediamine. Other catalysts such as 2,4,6-/m(/V,/V-dimethylaminomethyl)phenol are used in the presence of high levels of cmde MDI to promote trimerization of the isocyanate and thus form isocyanurate ring stmctures. These groups are more thermally stable than the urethane stmcture and hence are desirable for improved flammabiUty resistance (236). Some urethane content is desirable for improved physical properties such as abrasion resistance. 

At room temperature phenol is a white, crystalline mass. Phenol gradually turns pink if it contains impurities or is exposed to heat or light. It has a distinctive sweet, tarry odor, and burning taste. Phenol has limited solubiUty in water between 0 and 65°C. Above 65.3°C phenol and water are miscible in all proportions. It is very soluble in alcohol, ben2ene, chloroform, ether, and partially disassociated organics in general. It is less soluble in paraffinic hydrocarbons. The important physical properties of phenol are Hsted in Table 1. 

Special resoles are obtained with amine catalysts, which affect chemical and physical properties because amine is incorporated into the resin. For example, the reaction of phenol, formaldehyde, and dimethylamine is essentially quantitative (28). 

Of course, the physical properties of alkylphenols are comparable to phenol. The properties are strongly influenced by the type of alkyl substituent and its position on the ring. Alkylphenols, like phenol, are typically soflds at 25°C. Their form is affected by the size and configuration of the alkyl group, its position on the ring, and purity. They appear colorless, or white, to a pale yellow when pure (Table 1). 

Riboflavin forms fine yellow to orange-yeUow needles with a bitter taste from 2 N acetic acid, alcohol, water, or pyridine. It melts with decomposition at 278—279°C (darkens at ca 240°C). The solubihty of riboflavin in water is 10—13 mg/100 mL at 25—27.5°C, and in absolute ethanol 4.5 mg/100 mL at 27.5°C it is slightly soluble in amyl alcohol, cyclohexanol, benzyl alcohol, amyl acetate, and phenol, but insoluble in ether, chloroform, acetone, and benzene. It is very soluble in dilute alkah, but these solutions are unstable. Various polymorphic crystalline forms of riboflavin exhibit variations in physical properties. In aqueous nicotinamide solution at pH 5, solubihty increases from 0.1 to 2.5% as the nicotinamide concentration increases from 5 to 50% (9). 

Phenolic Resins. PhenoHc resins [9003-35 ] (qv) are thermosets prepared by the reaction of phenol with formaldehyde, through either the base-cataly2ed one-stage or the acid-cataly2ed two-stage process. The Hquid intermediate may be used as an adhesive and bonding resin for plywood, particle board, ftberboard, insulation, and cores for laminates. The physical properties for typical phenoHc laminates made with wood are Hsted in Table 1. 

The general proportions may be varied from one end of the tower to the other to accommodate changing liquid volumes and physical properties. These towers have been used in diameters ranging from a few inches for laboratory work up to 2.4 m (8 ft) in diameter by 12.2 m (40 ft) tall for purposes of deasphalting petroleum. Other commercial services include furfural extraction of lubricating oils, desulfurization of gasoline, phenol recoveiy from wastewaters, and many others. Columns up to 4.5 m in diameter and up to 50 m in height have been constructed. 

Unless great care is taken in control of phenol/acetone ratios, reaction conditions and the use of catalysts, a number of undesirable by-products may be obtained such as the o-,p- and o-,o- isomers of bis-phenol A and certain chroman-type structures. Although tolerable when the bis-phenol A is used in epoxy resins, these have adverse effects on both physical properties and the colour of polycarbonate resins. 

Table 23.3 Average physical properties of phenolic resin-based laminates...

Moulding powders based on melamine-phenol-formaldehyde resins were introduced by Bakelite Ltd, in the early 1960s. Some of the principal physical properties of mouldings from these materials are given in Table 24.1. 

Later, Farnham and Johnson reported the synthesis of higher molecular weight, tiiermoplastic polyfarylcnc etiier)s with good thermal, oxidative, chemical stability, and physical properties by reacting (at 120-260°C) a phenolate metal salt... 

Phthalazinone, 355 synthesis of, 356 Phthalic anhydride, 101 Phthalic anhydride-glycerol reaction, 19 Physical properties. See also Barrier properties Dielectric properties Mechanical properties Molecular weight Optical properties Structure-property relationships Thermal properties of aliphatic polyesters, 40-44 of aromatic-aliphatic polyesters, 44-47 of aromatic polyesters, 47-53 of aromatic polymers, 273-274 of epoxy-phenol networks, 413-416 molecular weight and, 3 of PBT, PEN, and PTT, 44-46 of polyester-ether thermoplastic elastomers, 54 of polyesters, 32-60 of polyimides, 273-287 of polymers, 3... 

To improve selectivity towards phenol 0.5 wt% of Sn was added as a promoter while preparing 5.0Fe/AC catalyst. The catalytic performance of 5.0Fe-0.5Sn/AC catalyst was investigated under similar reaction conditions. The addition of Sn to Fe/AC catalyst seems to enhance phenol selectivity by 33% (Fig. 7). TOF and physical properties of iron loaded catalysts are shown in Table 1. 

Organophosphate Ester Hydraulic Fluids. Organophosphate esters are made by condensing an alcohol (aryl or alkyl) with phosphorus oxychloride in the presence of a metal catalyst (Muir 1984) to produce trialkyl, tri(alkyl/aryl), or triaryl phosphates. For the aryl phosphates, phenol or mixtures of alkylated phenols (e.g., isobutylated phenol, a mixture of several /-butylphenols) are used as the starting alcohols to produce potentially very complex mixtures of organophosphate esters. Some phosphate esters (e.g., tricresyl and trixylyl phosphates) are made from phenolic mixtures such as cresylic acid, which is a complex mixture of many phenolic compounds. The composition of these phenols varies with the source of the cresylic acid, as does the resultant phosphate ester. The phosphate esters manufactured from alkylated phenylated phenols are expected to have less batch-to-batch variations than the cresylic acid derived phosphate esters. The differences in physical properties between different manufacturers of the same phosphate ester are expected to be larger than batch-to-batch variations within one manufacturer. 

ZnO photocatalyst can also be coupled with other materials in order to improve its chemical and physical properties [183] and photocatalytic activity [184]. Nanosized ZnO was immobilized on aluminum foil for the degradation of phenol [185]. Lanthanum and ZnO were combined to degrade 2,4,6-trichlorophenol [186]. Compared with Ti02 nanomaterial, ZnO nanomaterial generally absorbs a significant amount of the solar spectrum in the visible range therefore, ZnO nanomaterials were combined with Ti02 nanomaterials used as a photocatalyst [187]. 

Alkyl orthophosphate triesters, 79 41 terteAlkyl peroxycarbamates, decomposition of, 78 486 Alkyl peroxyesters, 78 478-487 chemical properties of, 78 480 487 physical properties of, 78 480 primary and secondary, 78 485 synthesis of, 78 478-480 synthetic routes to, 78 479 tert-Alkyl peroxyesters, 78 480 84, 485 as free-radical initiators, 74 284-286 properties of, 78 481-483t uses of, 78 487 Alkylperoxy radical, 74 291 Alkyl phenol ethoxylates, 8 678, 693 ... 

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