Mixed phenols

Phenolphthalein. Alophen, Ex-Lax, Feen-a-Miat, Modane, and Phenolax are trade names for phenolphthaleia [77-09-8] (3,3-bis(4-hydroxyphen5l)-l-(3ff)-l isobensofuranone) (10). It is a white or faintiy yellowish white crystalline powder, odorless and stable ia air, and practically iasoluble ia water one gram is soluble ia 15 mL alcohol and 100 mL diethyl ether. Phenolphthaleia may be prepared by mixing phenol, phthaHc anhydride, and sulfuric acid, and heating at 120°C for 10—12 h. The product is extracted with boiling water, then the residue dissolved ia dilute sodium hydroxide solution, filtered, and precipitated with acid. 

Extrusion compounders such as the Buss Ko-Kneader have been used for mixing phenolic resins. It is elaimed that they produce in some respects a better produet and are more eeonomical to use than mill-mixers. 

An additional activating hydroxyl group on the phenolic ring allows resorcinol to react rapidly widi formaldehyde even in die absence of catalysts.8 Hiis provides a method for room temperature cure of resorcinol-formaldehyde resins or mixed phenol-formaldehyde/resorcinol-formaldehyde resins. Trihydric phenols have not achieved commercial importance, probably due to tiieir higher costs. 

To explore the coordination abilities of mixed phenol-bpy/phen/terpy polydentate chelating ligands, Ward et al. investigated complexes (319) (Cu-Cu 3.050 A moderate AF coupling),281,282 (320) (moderate AF coupling),283 and (321) (Cu-Cu 3.324 A weak AF coupling).28... 

About fifty yeabs ago, Dr. Leo H. Baekeland, a Belgian-born American chemist, mixed phenol and formaldehyde together during an experiment. Other chemists had done this before Baekeland and had wondered how to get the messy goo that resulted out of their test tubes. But Baekeland had another approach. He asked himself, What is it good for ... 

K. Liebermann s Reagent is prepd by mixing phenol with coned sulfuric acid. The test consists in warming a small amt of the unknown substance with few drops of the reagent and observing the color produced. Aromatic nitroso compds and aliphatic nitroso- and isonitroso compds produce a red color which, turns blue... 

Regioselective reductive openings of mixed phenolic-benzylic cyclic acetals, using BH3-NMe3-AlCl3, under mild conditions to yield a benzylic ether and free the phenol group have been attributed to association of boron with the more basic oxygen (benzylic) followed by reaction with aluminium chloride.309... 

In the past, phenolic mixes were simply a combination of the phenolic resin with a filler such as walnut shell flour or pecan shell flour. These type mixes are still used in some hardwood exterior plywood. Todays phenolic glue mixes for softwood plywood involve mixing phenolic resin with water, filler, extender and sodium hydroxide (usually 50 percent). 

Phenol Hydrogenation. In principle, appropriate lignin deconstruction processes will provide a stream of mixed phenols. Reduction of these phenols will lead to a new source of cyclic aliphatic alcohols of potential use in the manufacture of adipic acid derivatives. Several catalytic processes for these types of reductions have appeared for phenol and should be applicable to lignin-derived mixed phenols. Phenol itself is reduced to cyclohexanol in the presence of various heterogeneous catalysts based on Pd.530-535... 

Salicylic Alcohol.—Such a compound is a mixed phenol and aromatic alcohol. The corresponding derivative of methyl alcohol, viz., the ortho compound, occurs combined with glucose as a glucoside known... 

Alcohol-aldehydes and -ketones.— If the hydroxyl group in hydroxy aldehydes and ketones is in the side chain instead of the ring then the compounds instead of being mixed phenol-aldehydes will be alcohol-aldehydes or -ketones c.g.,... 

Finally, the overall behavior of urea toward formaldehyde is much different than is the behavior of, for example, formaldehyde with phenol. Mixing phenol and formaldehyde at a ratio of 4 1 in an acidic medium will result in a reaction of impressive vigor. At ratios of 4 1 urea and formaldehyde are not capable of advancing under acidic conditions even with the application of heat. Urea-formaldehyde concentrate, a stable mixture of urea and formaldehyde at a mole ratio of 4.8 1 and concentrations of as high as 85% solids, is a common material of commerce. These observations, taken together, are not consistent with the orderly formation of a urea-formaldehyde condensation polymer. 

The total Phenolic and Other Tar Acid Resins class is broken down by chemical composition. In breaking down tar acid total resins by chemical composition, the Tariff Commissiop s annual figures from 1937 to 1948 (11) originally made the first breakdown phenolic resins other than mixed phenolics, and the second breakdown mixed phenolics. For 1949 and 1950, the breakdown is first by phenolic resins, unmodified, and secondly phenolic resins, modified. During 1948, it is possible to bridge the gap between these two breakdowns because both are given for that particular year. The first breakdown now, however, is between unmodified and modified resins, and each breakdown is followed by a more detailed breakdown by chemical composition. 

In the breakdown by chemical composition, phenol-formaldehyde protective coating resins are broken out from 1941 through 1946. Cresol-formaldehyde (cresylic acid-formaldehyde) protective coating resins are broken out for 1941 through 1943. p-tert-Amy -phenol-formaldehyde is shown separately for 1945 and 1946. Phenol and cresol-aldehyde resins are shown in 1941 and 1952. Mixed phenolic resins are shown for protective coatings in 1945 and 1946 (71). 

In 1865 just prior to Kekule s synthesis of phenol, Joseph Lister (1827-1912) was experimenting with carbolic acid as an aid to antiseptic surgery which he had pioneered. A mixture of crystallised carbolic acid and shellac (lac plaster) was employed in the finally adopted mode of application. The requirement of phenol for the manufacture of picric acid during the Boer war and other uses resulted in a demand which soon outstripped the resources of phenol/cresols available from coal distillation. Synthetic phenol thus became a potentially important intermediate. The lengthy processing involved in the separation of phenol and the isomeric cresols led to the desirability for specific syntheses. In 1978 of the world production of phenol only 3% came from coal sources by extraction of the mixed phenols (about 1.5% in coal tar) with 10% sodium hydroxide, acidification with carbon dbxide and separation. Phenolic compounds are also formed during catalytic cracking processes in the petroleum industry. There are historically six industriai processes for the production of synthetic phenol, variously from benzene and toluene, some of which are also applicable to the cresols and the dihydric phenols. 

Another approach is slurry molding and this technique was firstly used to manufacture carbon-carbon composites by Besmann et al. (2003). This process mixes phenolic resin with carbon fillers in water to create slurry which is fed out and vacuum molded into a preform. A second process called carbon chemical vapor infiltration (CVl) is then used to seal the plate for gas impermeability and for improvement of electrical conductivity. This process has been further developed by Huang et al. (2005) to reduce the cost caused by the CVl process and by Cunningham et al. (2007) to improve the properties of the bipolar plates. However, the mechanical properties of the bipolar plates were not found to be as high as the solely wet-lay-based plates (see Figures 6.7 and 6.8). 

Cresylic Acid 113-266 45-130 E E cresylic acid, phenol, formaldehyde, sulfuric acid, ethylenediamine. phosphoric acid, sodium hydroxide, carbon dioxide, ammonia, barium hydroxide. Corrosive media varied from mixed phenol and sulfuric acid at 266 F to 20% sodium hydroxide at 212 F. (Batch-basis manufacture of phenolic resins and varnishes), moderate aeration... 

Thyme Oil. To estimate the components of the mixture of thymol and carvacrol present in the oil, the melting-point of the dried mixed phenols obtained by light petroleum extraction was taken by Sage and Dalton and the percentage read from a curve prepared from known mixtures. 

Figure 5.8 Schematic of the proposed heat flow in hybrid and mixed phenolic composites.

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