Phenol , characterization

Typical constituents of sour wastewater streams from crude distillation include hydrogen sulfide, ammonia, suspended solids, chlorides, mercaptans, and phenol, characterized by a high pH. Combined flows from atmospheric and vacuum distillation are about 26.0 gallons per barrel of oil, and represent one of the largest sources of wastewater in a refinery. 

Whereas LC-MS has been applied in the detection and characterization of other plant natnral prodnets, it was decided to foens on plant phenols, especially flavonoids. A general classification of plant phenols is given in Table 15.1. The application of MS to plant phenol characterization was reviewed [1]. 

Bakhouche, A., Lozano-Sanchez, J., Beltran-Debon, R., Joven, J., Segura-Carretero, A., and Femandez-Gutierrez, A. 2013. Phenolic characterization and geographical classification of commercial Arbequina extra-virgin olive oils produced in southern Catalonia. Food Res. Int. 50 401-408. 

Anthocyanins are a group of plant phenolics characterized by their blue-orange-red color. They have a double interest as plant constituents, one technological, since they can not only be used as natural colorants in the food industry but also can interact with other plant components influencing the final characteristics of the processed product, and the other is related to their implications on human health as they can be considered functional ingredients and have shown themselves as potential targets for the pharmacological industry. 

These compounds are a kind of nonflavonoid phenolics characterized by the C6-C3 structure. Hydroxycinnamic acids are abundant in... 

This experiment describes a characterization analysis in which the degree of association, equilibrium constant, and hydrogen bond energy are measured for benzyl alcohol and phenol in CCI4. 

Phenol s chemical properties are characterized by the influences of the hydroxyl group and the aromatic ring upon each other. Although the stmcture of phenol is similar to cyclohexanol, phenol is a much stronger acid. Its piC in aqueous solution at 25°C is 9.89 x 10 ° (8). This characteristic allows aqueous hydroxides to convert phenol into their salts. The salts, especially those of sodium and potassium, are converted back into phenol by aqueous mineral acids or carboxyhc acids. 

In this section the rosins and rosin derivative resins, coumarone-indene and hydrocarbon resins, polyterpene resins and phenolic resins will be considered. The manufacture and structural characteristics of natural and synthetic resins will be first considered. In a second part of this section, the characterization and main properties of the resins will be described. Finally, the tackifier function of resins in rubbers will be considered. 

By constructing a pinch diagram for the problem, find the minimum cost of MSAs needed to remove phenol from Rg and R2. How do you characterize the point at which both composite streams touch Is it a true pinch point ... 

Phenols (Section 24.1) Family of compounds characterized by a hydroxyl substituent on an aromatic ring as in ArOH. Phenol is also the name of the parent compound, CgHjOH. 

R. Antony, Synthesis, Characterization and Thermal Behaviour of Chemically Modified Phenolic and Substituted Phenolic Polymers, Ph.D thesis. Regional Research Laboratory, Trivandrum and Kerala University, Trivandrum, India (1993). 

Amino resins are characterized by being more clear and harder (tensile strength) than phenolics. However, their impact strength (breakabil-ity) and heat resistance are lower. Melamine resins have better heat and moisture resistance and better hardness than their urea analogs. 

This chapter emphasizes the recent mechanistic and kinetic findings on phenolic oligomer syntheses and network formation. The synthesis and characterization of both novolac- and resole-type phenolic resins and dieir resulting networks are described. Three types of networks, novolac-hexamethylenetetramine (HMTA),... 

The most widely used molecular weight characterization method has been GPC, which separates compounds based on hydrodynamic volume. State-of-the-art GPC instruments are equipped with a concentration detector (e.g., differential refractometer, UV, and/or IR) in combination with viscosity or light scattering. A viscosity detector provides in-line solution viscosity data at each elution volume, which in combination with a concentration measurement can be converted to specific viscosity. Since the polymer concentration at each elution volume is quite dilute, the specific viscosity is considered a reasonable approximation for the dilute solution s intrinsic viscosity. The plot of log[r]]M versus elution volume (where [) ] is the intrinsic viscosity) provides a universal calibration curve from which absolute molecular weights of a variety of polymers can be obtained. Unfortunately, many reported analyses for phenolic oligomers and resins are simply based on polystyrene standards and only provide relative molecular weights instead of absolute numbers. 

Various ionization methods were used to bombard phenol-formaldehyde oligomers in mass spectroscopic analysis. The molecular weights of resole resins were calculated using field desorption mass spectroscopy of acetyl-derivatized samples.74 Phenol acetylation was used to enable quantitative characterization of all molecular fractions by increasing the molecular weights in increments of 42. 

Network properties and microscopic structures of various epoxy resins cross-linked by phenolic novolacs were investigated by Suzuki et al.97 Positron annihilation spectroscopy (PAS) was utilized to characterize intermolecular spacing of networks and the results were compared to bulk polymer properties. The lifetimes (t3) and intensities (/3) of the active species (positronium ions) correspond to volume and number of holes which constitute the free volume in the network. Networks cured with flexible epoxies had more holes throughout the temperature range, and the space increased with temperature increases. Glass transition temperatures and thermal expansion coefficients (a) were calculated from plots of t3 versus temperature. The Tgs and thermal expansion coefficients obtained from PAS were lower titan those obtained from thermomechanical analysis. These differences were attributed to micro-Brownian motions determined by PAS versus macroscopic polymer properties determined by thermomechanical analysis. 

Most frequently, SEC with dextran-, pullulan-, or polystyrene calibration standards has been used to characterize the molecular properties of xylans. However, as for viscometric studies [108], a sufficient solvent ionic strength is a prerequisite for useful SEC measurements of charged polysaccharides, including glucuronoxylans [111-113]. An advantage of the SEC technique is that the presence of protein and phenolic components or oxidative changes can be detected by simultaneous ultraviolet (UV) detection. 

Complexes. The structure of an n a charge-transfer complex between quinoxaline and two iodine atoms has been obtained by X-ray analysis and its thermal stability compared with those of related complexes. The hydrogen bond complex between quinoxaline and phenol has been studied by infrared spectroscopy and compared with many similar complexes. Adducts of quinoxaline with uranium salts and with a variety of copper(II) alkano-ates have been prepared, characterized, and studied with respect to IR spectra or magnetic properties, respectively. 

This fluorescent acid chloride can be used to form derivatives of alcohols, amines, and phenols. Using these fluorescent derivatives, an analysis of a series of n-alcohols from Ci to C4 was developed. A chromatogram produced by this technique is shown in Figure 3. Derivatives were also formed from ammonia, dimethylamine, and phenol. A derivative was formed from pentachlorophenol but was not fully characterized. The quantum yields of fluorescence of the alcohol derivatives of V were lower than those of the alkyl halide derivatives of III. 

Up to now, nine classes of different polyphosphazenes are known and characterized substituted with aliphatic alcohols [40,41,262-281] or phenols [41,95, 277,282-297],with aliphatic [42,298-300] or aromatic [301-304] amino groups, with di-functional spiro hydroxy (e.g. dihydroxybiphenyl [305] or di hydroxy-... 

Yields in the above reactions can often be improved by the addition of 1 mole of triphenylphosphine directly to the trifluoroacetic acid solution of the reactants immediately before final work-up. It would appear that the triphenylphosphine functions as a scavenger for TTFA released in the metal-metal exchange reaction, thus protecting the final phenol from further electrophilic thallation and/or oxidation. Validation of the metal-metal exchange mechanism was obtained indirectly by isolation and characterization of an ArTlX2/LTTFA complex directly from the reaction mixture. NMR analysis revealed that this complex still possessed an intact aryl-thallium bond, indicating that it was probably the precursor to the transmetallation products, an aryllead tristrifluoroacetate and TTFA. 

Iron impregnated on activated carbon was used as catalyst for the direct synthesis of phenol from benzene. The effect of Sn addition to the catalyst was studied. The prepared catalysts were characterized by BET, SEM and XRD analysis. The catalyst 5.0Fe/AC showed good activity in the conversion of benzene and addition of Sn seemed to improve the selectivity of phenol in the reaction. 

Although catalytic wet oxidation of acetic acid, phenol, and p-coumaric acid has been reported for Co-Bi composites and CoOx-based mixed metal oxides [3-5], we could find no studies of the wet oxidation of CHCs over supported CoO catalysts. Therefore, this study was conducted to see if such catalysts are available for wet oxidation of trichloroethylene (TCE) as a model CHC in a continuous flow fixal-bed reactor that requires no subsequent separation process. The supported CoOx catalysts were characterized to explain unsteady-state behavior in activity for a certain hour on stream. 

HUDSON A, DiNH p A, KOKUBUN T, siMMONDS M s, GESCHER A (2000) Characterization of potentially chemopreventive phenols in extracts of brown rice that inhibit the growth of human breast and colon cancer cells. Cancer Epidemiol Biomarkers Prev, 9 (11) 1163-70. 

Hong, V. and Wrolstad, R.E., Use of HPLC separation/photodiode array detection for characterization of anthocyanins, J. Agric. Food Chem., 38, 708, 1990. Osmianski, J. and Lee, C.Y., Isolation and HPLC determination of phenolic compounds in red grapes. Am. J. Enol. Vitic., 41, 204, 1990. 

ESI-MS has emerged as a powerful technique for the characterization of biomolecules, and is the most versatile ionization technique in existence today. This highly sensitive and soft ionization technique allows mass spectrometric analysis of thermolabile, non-volatile, and polar compounds and produces intact ions from large and complex species in solution. In addition, it has the ability to introduce liquid samples to a mass detector with minimum manipulation. Volatile acids (such as formic acid and acetic acid) are often added to the mobile phase as well to protonate anthocyanins. A chromatogram with only the base peak for every mass spectrum provides more readily interpretable data because of fewer interference peaks. Cleaner mass spectra are achieved if anthocyanins are isolated from other phenolics by the use of C18 solid phase purification. - ... 

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