Phenolic-based compounds

Figure 2.33. Experimental data illustrating the effect of a decrease in the induction period during curing of a phenolic-based compound at different shear rates 0.015 s 1 (curve 1) 0.95 s 1 (curve 2) 3.75 s 1 (curve 3) ...

Figure 2.34. Comparison of theoretical predictions (curve, calculated from Eq. (2.8S) according to the dissipative model of non-isothermal curing) with experimental data on the decrease of the induction period at high shear rates for phenolic-based compounds (vertical bars) and silicon-based composites at different initial temperatures 150°C (1) 170°C (2) and 190°C (3).

Phenol Hydroxy benzene biopolymers built with phenol-based compounds that have oxygen-containing groups attached to the central aromatic ring are common in higher plants (lignins and tannins), but they are rare in algae and animals. 

When concentrations of superoxide anion are very low, assay sensitivity may need to be enhanced. Some enhancement reagents, such as indo-phenol, are phenolic-based compounds. Unfortunately, such enhancers are toxic to live cells and denaturing to some components of subcellular systems hence, they cannot be used for in situ assays. LumiMax increases photon output but is nontoxic and does not denature cellular components used in assaying live cell activity (Hoang and Pfeffer-KORN 1998). 

The intense reddish-brown color of the acetylacetone titanium complexes impart a yellow discoloration to white inks. This discoloration is accentuated when the inks are used to print substrates that contain phenol-based antioxidants. The phenoHc compounds react with the organic titanate to form a highly colored titanium phenolate. Replacement of 0.25 to 0.75 moles of acetylacetone with a malonic acid dialkyl ester, such as diethyl malonate, gives a titanium complex that maintains the performance advantages of the acetyl acetone titanium complexes, but which is only slightly yellow in color (505). These complexes still form highly colored titanium phenolates. 

Synthetic resins, such as phenoHc and cresyUc resins (see Phenolic resins), are the most commonly used friction material binders, and are usually modified with drying oils, elastomer, cardanol [37330-39-5] an epoxy, phosphoms- or boron-based compounds, or even combinations of two. They ate prepared by the addition of the appropriate phenol and formaldehyde [50-00-0] in the presence of an acidic or basic catalyst. Polymerization takes place at elevated temperatures. Other resin systems are based on elastomers (see Elastomers, synthetic), drying oils, or combinations of the above or other polymers. 

Phenol-formaldehyde resole resins, preparations of, 429 Phenolic-based networks, 376 Phenolic compounds, 62 Phenolic cyanate resins, 418... 

The total number of drugs eluted from KOH-treated phases is less than the number eluted from similar phase nontreated coluims. The KOH treatment is done to reduce the adsorption of compounds by the support phase, and although it does this well, it also prevents the elution of phenolic base drugs such as morphine because of conversion to nonvolatile potassium phenolates. Many higher molecular weight alkaloids become thermolabile under such alkaline conditions and do not elute. Non-KOH treated phases have less tendency to cause such decomposition. 

Hydroquinone and phenol based clathrates including Dianin s compound are based upon cages made up of 6-membered hydrogen bonded rings of hydroquinone and are subject to considerable synthetic variation. 

Another type of interaction is represented by hydrophobic interactions between the matrix and some of the components in the hydrolysate. When these interactions occur, the removal of a compound is dependent on the matrix polymer, rather than on the type of the functional groups. The results indicate that styrene- and phenol-based matrices (here represented by Dowex 1x4, Dowex 2x8, IRA 92, and Duolite A7) have an excellent ability to trap phenols, whereas acrylic-based matrices (representedby IRA 67and IRA 458) have poorer ability. Nevertheless, the concentration of phenolic compounds decreased by more than 20% after all treatments. 

Gibbons, J. P. Wondolowski, L. Carbohydrate-Phenol Based Condensation Resins Incorporating Nitrogen-Containing Compounds Canadian Patent 1 090 026, 1980. 

---