Phenolic distribution

For determination of phenol distribution coefficients the extraction proceeded for 15 minutes in order to reach equilibrium. The time required to reach equilibrium was determined by making five replicate injections of the headspace onto the SFC system. The first injection was after the extraction had proceeded for 15 minutes at 50°C and 100 atm. Following the equilibration time, four further injections at ten minute intervals were made, after which the pressure inside the extraction apparatus was increased and the system was again allowed to equilibrate (i.e. 15 minutes). The five replicate injection process was then repeated. The amount of phenol in each injection was then noted by referring to an external phenol standard calibration curve. As the total volume of the system was known, the amount of phenol in the SF could be calculated. The amount of phenol in the aqueous phase could then be calculated by mass balance. 

Figure 6. Phenol distribution coefficient as a function of temperature at constant density.

The presence of moisture in the soil was found to have no effect on the extraction of phenol using pure carbon dioxide. The effect of the presence of water may have been masked, since phenol distributes between water and supercritical carbon dioxide the same as it does between soil and supercritical carbon dioxide. However, the presence of water did have a dramatic impact on the effectiveness of the entrainers. The benzene/carbon dioxide mixture was able to remove essentially all of the phenol from the wetted soil. Since benzene is virtually insoluble in water, it highly favors the supercritical phase over the wetted soil phase. Hence the supercritical phase is able to attract almost all of the phenol, possibly due to chemical similarities between benzene and phenol. The methanol/carbon dioxide mixture, however, offered no enhancement over that of the pure carbon dioxide. As seen in the aqueous extractions, the methanol highly favors water and therefore is probably staying with the wetted soil. Therefore, the supercritical phase polarity is not increased as in the dry soil extractions and no solubility enhancement occurs. 

Again the uncertainty about the proportion of an observed result which is due to nitration and the proportion which is due to nitrosation exists. Thus, in expt. 11 phenol was being nitrated above the encounter rate and the observed isomer distribution could arise from a combination of nitration by whatever is the usual electrophile with nitration by a new, less reactive electrophile, or with nitrosation, or all three processes could be at work. 

Phenol IS both an important industrial chemical and the parent of a large class of compounds widely distributed as natural products Although ben zenol IS the systematic name for CgHsOH the lUPAC rules permit phe nol to be used instead Substituted derivatives are named on the basis of phenol as the parent compound... 

The plastici2er performance of isopropylphenyl diphenyl phosphate [28108-99-8], [68937-41-7], [68782-95-6], C2 H2 04P, is close to that of tricresyl phosphate. It is made from the product of isopropylation of phenol by propylene. The phosphate is a mixture of mainly 0- and -isomers and contains a distribution of different levels of alkylation (101,102). 

Phenolic resin substantially increases open time and peel strength of the formulation (80). For example, higher methylol and methylene ether contents of the resin improves peel strength and elevated temperature resistance. Adhesive properties are also influenced by the molecular weight distribution of the phenoHc low molecular weight reduces adhesion (82). 

Commercial alkylphenol ethoxylates are almost always produced by base-cataly2ed ethoxylation of alkylphenols. Because phenols are more strongly acidic than alcohols, reaction with ethylene oxide to form the monoadduct is faster. The product, therefore, does not contain unreacted phenol. Thus, the distribution of individual ethoxylates in the commercial mixture is narrower, and alkylphenol ethoxylates are more soluble in water. 

At present, chlorine dioxide is primarily used as a bleaching chemical in the pulp and paper industry. It is also used in large amounts by the textile industry, as well as for the aching of flour, fats, oils, and waxes. In treating drinking water, chlorine dioxide is used in this country for taste and odor control, decolorization, disinfection, provision of residual disinfectant in water distribution systems, and oxidation of iron, manganese, and organics. The principal use of chlorine dioxide in the United States is for the removal of taste and odor caused by phenolic compounds in raw water supplies. 

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