Phenol Substances

Generally, phenols themselves are colourless. However, they are easily oxidized to form coloured substances. Phenols are acidic in nature and most phenols have values of 10... 

Tor a viseosimetrio examination of the influence of certain organic substances ( .transformation temperature, see Mondain-Monval and Schneider, Cornet, rend., 1928, 186, 751. 

I McMurrough, JR Byrne. HPLC analysis of bittering substances, phenolic compounds, and various compounds of alcoholic beverages. In LML Nollet, ed. Food Analysis by HPLC. New York Marcel Dekker, 1992, pp 579-641. 

N. G. Yaroslavskii. Metody Issle-dovaniya Struktury Vysokodispers. Poristykh Tel (Moscow) 1953,153-63. IR spectra of porous glass with adsorbed substances, phenol, aniline, pyridine. 

There are numerous refeieitces that include chemical analyses of fast pyrolysis liquids from a variety of sources, including slow pyrolysis tar, fast pyrolysis liquid and fractions thereof. As fast pyrolysis liquid may be raw, treated, filtered, catalytically derived, upgraded and dependent on the process parameters, a "worst case" must be taken for the liquid compositioii, i.e. high variability. As noted, fast pyrolysis liquid falls within Class 3, based on its physical properties, however, this is further complicated by the presence of other chemicals that are in Class 6.1 - Toxic substances [phenols, etc.] which ate in concentrations above 0.1 wt%. A typical analysis of several fast pyrolysis liquids from different laboratories is given in Table 2. 

Cigarette smoke condensate may be richer in tumour-promoting substances than in tumour-initiating substances. Phenolic compounds may be responsible for much of its promoting activity. 

BGVV Empfehlung XL for Germany. Depending on the raw material, most as-sup-plied resols contain relatively large amounts of toxic substances (phenols, formaldehyde, etc.). They must therefore be properly labelled, stored, and handled. As a result of improvements in production methods and the choice of suitable raw materials, useable resols with greatly reduced levels of toxic substance have been developed and made available to the paint industry. 

Protivova and Pospisil [19] have reported on the behaviour of some amine antioxidants and antiozonants and some model substances (phenols, aromatic hydrocarbons and amines)... 

Reacting substances phenols, enols, aliphatic amino acids, mer-captans, thiophenols, antipyrine, and pyramidon. 

Use of impure waters often leads to many problems like health complications, decrease in the efficiency of plants, increased cost, etc. However, of the wide range of impurities present, only a few may affect a particular process. Therefore, removal or reduction in the concentration of only these impurities is necessary the rest of the impurities which do not adversely affect the process may be allowed to remain as such. For example, water for laundries should be soft and free from colour water for steam generation should be free from all dissolved solids and dissolved corrosive gases but removal of bacteria is not required. Specifications for drinking water are much more stringent with respect to the presence of pathogenic bacteria and certain toxic substances (Phenols < 0.005 ppm As, Cr, Pb, Ag, Mn < 0.05 ppm Cd, Se, cyanide < 0.01 ppm etc.) but may contain large amounts of substances like Ca "", Mg , Na, K, Cl ", 804 , etc. 

The nitro-hydrocarbons are neutral substances but when a nitro-group is introduced into a phenol or amine the acidic properties are greatly increased or the basicity decreased. The presence of a nitro-group also tends to make halogen atoms in the same molecule much more reactive. 

Pure phenol is a colourless crystalline substance, having m.p. 43°, and b.p. 182° on exposure to air, it slowly sublimes, and on exposure to light, develops a pink colour. It has a characteristic odour, and a limited solubility in water. Phenol in dilute aqueous solution has strongly antiseptic properties, but the crystalline substance should not be allowed to come in contact with the skin, as it may cause severe blistering. 

Although these nitrations proceed smoothly, attempted nitration of an unidentified substance should always be carried out with extreme care, e.g., by working in a fume-cupboard and pointing the boiling-tube away from the operator. Many organic substances e.g., alcohols and phenols) react with great violence with a mixture of nitric and sulphuric acids. 

If the third substance dissolves in only one of the liquids, it is found that their mutual solubilities are decreased and the C.S.T. is generally raised. For example, a concentration of 0 15 mol of potassium chloride per litre of water raises the C.S.T. of the water - phenol system by about 12° a similar concentration of naphthalene in the phenol produces a rise of about 30°. 

If the third substance dissolves in both liquids (and the solubility in each of the liquids is of the same order), the mutual solubility of the liquids will be increased and an upper C.S.T. will be lowered, as is the case when succinic acid or sodium oleate is added to the phenol - water system. A 0 083 molar solution of sodium oleate lowers the C.S.T. by 56 -7° this large effect has been applied industrially in the preparation of the disinfectant sold under the name of Lysol. Mixtures of tar acids (phenol cresols) do not mix completely with water at the ordinary temperature, but the addition of a small amount of soap ( = sodium oleate) lowers the miscibility temperature so that Lysol exists as a clear liquid at the ordinary temperature. 

A brief account of aromatic substitution may be usefully given here as it will assist the student in predicting the orientation of disubstituted benzene derivatives produced in the different substitution reactions. For the nitration of nitrobenzene the substance must be heated with a mixture of fuming nitric acid and concentrated sulphuric acid the product is largely ni-dinitrobenzene (about 90 per cent.), accompanied by a little o-dinitrobenzene (about 5 per cent.) which is eliminated in the recrystallisation process. On the other hand phenol can be easily nitrated with dilute nitric acid to yield a mixture of ortho and para nitrophenols. It may be said, therefore, that orientation is meta with the... 

The phenyl propionate may be prepared by slowly adding 196 g. (120 ml.) of redistilled thionyl chloride to a mixture of I50g. of pure phenol and 132 g. (133 ml.) of propionic acid (compare Fig. 111,31, 1), warming to drive all the sulphur dioxide and hydrogen chloride, and distilling 190 g. of phenyl propionate, b.p. 202-212° (the pure substance boils at 211°) are obtained. 

V. L. Singleton and P. Esau, Phenolic Substances of Grapes and Wine, and Their Significance, Adv. Food Res., Suppl. 1, (1969). 

---