Phenohc derivatives

Disinfection destroys pathogenic organisms. This procedure can render an object safe for use. Disinfectants include solutions of hypochlorites, tinctures of iodine or iodophores, phenoHc derivatives, quaternary ammonium salts, ethyl alcohol, formaldehyde, glutaraldehyde, and hydrogen peroxide (see Disinfectants AND antiseptics). Effective use of disinfected materials must be judged by properly trained personnel. 

Amination of phenoHc derivatives is limited to specially developed catalytic processes for aniline and y -toluidine (3). More general conditions apply to amination of naphthols by the Bucherer reaction. Important intermediates made by a Bucherer reaction include Tobias acid and gamma acid. 

This pharmaceutical was removed from the USP but it is still listed in its British counterpart. A phenohc derivative of pyridine. 

Many other chemicals have become more expensive because of increases in the price of upstream intermediates. Tin stabilisers are affected by the rising price of tin metal and epoxy derivatives are also affected, with basic epoxy resins going up by about 200 euros/tonne in Eiuope in mid-2004. Some phenohc derivatives have also risen dramatically in price. A snapshot over two or three months diuing mid-2004 shows substantial price increases being announced by leading suppliers for impact modifiers, waxes, silica, phosphorus flame retardants and, as indicated earlier, brominated types. Plasticiser producers were also attempting price increases for DINP and DEHP. 

Uses. Furfuryl alcohol is widely used as a monomer in manufacturing furfuryl alcohol resins, and as a reactive solvent in a variety of synthetic resins and appHcations. Resins derived from furfuryl alcohol are the most important appHcation for furfuryl alcohol in both utihty and volume. The final cross-linked products display outstanding chemical, thermal, and mechanical properties. They are also heat-stable and remarkably resistant to acids, alkaUes, and solvents. Many commercial resins of various compositions and properties have been prepared by polymerization of furfuryl alcohol and other co-reactants such as furfural, formaldehyde, glyoxal, resorcinol, phenoHc compounds and urea. In 1992, domestic furfuryl alcohol consumption was estimated at 47 million pounds (38). 

Fig. 21. Representative nonionic photoacid generators. A variety of photochemical mechanisms for acid production ate represented. In each case a sulfonic acid derivative is produced (25,56,58—60). (a) PAG that generates acid via 0-nitrobenzyl rearrangement (b) PAG that generates acid via electron transfer with phenohc matrix (c) PAG that is active at long wavelengths via electron-transfer sensitization (d) PAG that generates both carboxylic acid and...

Fibers for commercial and domestic use are broadly classified as natural or synthetic. The natural fibers are vegetable, animal, or mineral ia origin. Vegetable fibers, as the name implies, are derived from plants. The principal chemical component ia plants is cellulose, and therefore they are also referred to as ceUulosic fibers. The fibers are usually bound by a natural phenoHc polymer, lignin, which also is frequentiy present ia the cell wall of the fiber thus vegetable fibers are also often referred to as lignocellulosic fibers, except for cotton which does not contain lignin. 

The term naphthenic acid, as commonly used in the petroleum industry, refers collectively to all of the carboxyUc acids present in cmde oil. Naphthenic acids [1338-24-5] are classified as monobasic carboxyUc acids of the general formula RCOOH, where R represents the naphthene moiety consisting of cyclopentane and cyclohexane derivatives. Naphthenic acids are composed predorninandy of aLkyl-substituted cycloaUphatic carboxyUc acids, with smaller amounts of acycHc aUphatic (paraffinic or fatty) acids. Aromatic, olefinic, hydroxy, and dibasic acids are considered to be minor components. Commercial naphthenic acids also contain varying amounts of unsaponifiable hydrocarbons, phenoHc compounds, sulfur compounds, and water. The complex mixture of acids is derived from straight-mn distillates of petroleum, mosdy from kerosene and diesel fractions (see Petroleum). 

Lignite, generally leonardite, and lignite derivatives are appHed in water-based muds as thinners and filtration control agents. Leonardite is an oxidized lignite having a high content of humic acids, which may be described as carboxylated phenoHc polymers (59,60). Litde is known about the chemical stmcture. 

The largest outlet for phenol worldwide is phenoHc resins (qv). However, the growth rate of bisphenol A is higher than that of the other significant derivatives and is projected to become the principal use of phenol in the future (see Epoxy resins Polycarbonates). Table 6 shows the portion of world phenol demand by use and the anticipated growth rate of the uses. 

Some other phenol derivatives are somewhat local in appHcation. Eor example, aniline is produced from phenol at only two plants, one in Japan and one in the United States. Likewise, phenol is used in the production of nylon, via caprolactam (qv) or adipic acid (qv) by only one United States producer and one European producer. These markets, like the phenoHc resin and polycarbonate markets, are quite cycHcal. Thus, the entire phenol market tends to be cycHcal and closely tied to the housing and automotive markets. 

Prices of phenolic resins vary substantially depending on the appHcation. In 1995, the price of general-purpose and semisoHds was 1.50— 1.80/kg, whereas epoxy-hardener grades can exceed 2.20/kg. Because raw materials of phenoHc resins are derived from cmde oil and natural gas, the prices of phenohc resins depend on the prices of these resources. 

Liquid crystal polyesters are made by a different route. Because they are phenoHc esters, they cannot be made by direct ester exchange between a diphenol and a lower dialkyl ester due to unfavorable reactivities. The usual method is the so-called reverse ester exchange or acidolysis reaction (96) where the phenoHc hydroxyl groups are acylated with a lower aHphatic acid anhydride, eg, acetic or propionic anhydride, and the acetate or propionate ester is heated with an aromatic dicarboxyHc acid, sometimes in the presence of a catalyst. The phenoHc polyester forms readily as the volatile lower acid distills from the reaction mixture. Many Hquid crystal polymers are derived formally from hydroxyacids (97,98) and thein acetates readily undergo self-condensation in the melt, stoichiometric balance being automatically obtained. 

The majority of 2-methylphenol is used in the production of novolak phenoHc resins. High purity novolaks based on 2-methylphenol are used in photoresist appHcations (37). Novolaks based on 2-methylphenol are also epoxidized with epichlorohydrin, yielding epoxy resins after dehydrohalogenation, which are used as encapsulating resins in the electronics industry. Other uses of 2-methylphenol include its conversion to a dinitro compound, 4,6-dinitro-2-methylphenol [534-52-1] (DNOC), which is used as a herbicide (38). DNOC is also used to a limited extent as a polymerization inhibitor in the production of styrene, but this use is expected to decline because of concerns about the toxicity of the dinitro derivative. 

Another significant use of 3-methylphenol is in the production of herbicides and insecticides. 2-/ f2 -Butyl-5-methylphenol is converted to the dinitro acetate derivative, 2-/ f2 -butyl-5-methyl-4,6-dinitrophenyl acetate [2487-01 -6] which is used as both a pre- and postemergent herbicide to control broad leaf weeds (42). Carbamate derivatives of 3-methylphenol based compounds are used as insecticides. The condensation of 3-methylphenol with formaldehyde yields a curable phenoHc resin. Since 3-methylphenol is trifunctional with respect to its reaction with formaldehyde, it is possible to form a thermosetting resin by the reaction of a prepolymer with paraformaldehyde or other suitable formaldehyde sources. 3-Methylphenol is also used in the production of fragrances and flavors. It is reduced with hydrogen under nickel catalysis and the corresponding esters are used as synthetic musk (see Table 3). 

A large number of hindered phenoHc antioxidants are based on the Michael addition of 2,6-di-/ f2 -butylphenol and methyl acrylate under basic catalysis to yield the hydrocinnamate which is a basic building block used in the production of octadecyl 3-(3,5-di-/ f2 butyl-4-hydroxyphenyl)propionate, [2082-79-3], tetrakis(methylene-3(3,5-di-/ f2 butyl-4-hydroxylphenyl)propionate)methane [6683-19-8], and many others (63,64). These hindered phenolic antioxidants are the most widely used primary stabilizers in the world and are used in polyolefins, synthetic and natural mbber, styrenics, vinyl polymers, and engineering resins. 2,6-Di-/ f2 -butylphenol is converted to a methylene isocyanate which is trimerized to a triazine derivative... 

Hydroxyisoquinolines. Hydroxy groups in the 5-, 6-, 7-, and 8-position show phenoHc reactions for example, the Bucherer reaction leads to the corresponding anainoisoquinolines. Other typical reactions include the Mannich condensation, azo-coupling reactions, and nitrosation. Both 0-methyl and /V-methyl derivatives are obtained from the methylation of 1-hydroxyisoquinoline, indicating that both tautomeric forms are present. Distillation of various hydroxy compounds, eg, 1- and 4-hydroxyisoquinoline, with zinc dust removes the oxygen. Treatment of 1-isoquinolinol with phosphoms tribromide yields 1-bromoisoquinoline [1532-71 -4] (178). 

Coal tar is the condensation product obtained by cooling to approximately ambient temperature, the gas evolved in the destmctive distillation of coal. It is a black viscous Hquid denser than water and composed primarily of a complex mixture of condensed ring aromatic hydrocarbons. It may contain phenoHc compounds, aromatic nitrogen bases and their alkyl derivatives, and paraffinic and olefinic hydrocarbons. Coal-tar pitch is the residue from the distillation of coal tar. It is a black soHd having a softening point of 30—180°C (86—359°F). 

With amine initiators the so-called self-catalysed polyols are obtained, which are used in the formulation of rigid spray foam systems. The rigidity or stiffness of a foam is increased by aromatic initiators, such as Mannich bases derived from phenol, phenoHc resins, toluenediamine, or methylenedianiline... 

In the 1990s hplc has become widely used in the flavor and fragrance industry to measure vanillin and other phenoHc compounds. Routine methods have been developed that are particularly adapted to thermosensitive products, such as vanillin and its derivative products, with elution gradient and uv detection at given wavelengths. Certain critical impurities can thus routinely be traced to very low (10 ppm) concentrations. 

Tackifiers are used to increase the tackiness and the setting speed of adhesives. They increase tackiness by softening the poly(vinyl acetate) polymer in the wet and the dry adhesive film. Tackifiers are usually rosin or its derivatives or phenoHc resins. Other additives frequently needed for specific apphcation and service conditions are antifoams, biocides, wetting agents, and humectants. 

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