Phenols polymerization

Bitton R, Ben-Yehuda M, Davidovich M, Balazs Y, Potin P, Delage L, Colin C, Bianco-Peled H (2006) Structure of algal-born phenolic polymeric adhesives. Macromol Biosci 6 737-746 Bolwell GP, Davies RD, Gerrish C, Auh C-K, Murphy TM (1998) Comparative biochemistry of the oxidative burst produced by rose and French bean cells reveals two distinct mechanisms. Plant Physiol 116 1379-1385... 

Uses Manufacture of acetone, acetophenone, diisopropylbenzene, a-methylstyrene and phenol, polymerization catalysts constituent of motor fuel, asphalt, and naphtha catalyst for acrylic and polyester-type resins octane booster for gasoline solvent. 

Shutava T, Zheng ZG, John V, Lvov Y. Microcapsule modification with peroxidase-catalyzed phenol polymerization. Biomacromolecules 2004 5 914-921. 

Ryu K, McEldoon JP, Pokora AR, Cyrus W, Dordick JS (1993) Numerical and Monte Carlo simulations of phenolic polymerizations catalyzed by peroxidase. Biotechnol Bioeng 42 807-814... 

Hindered phenols, polymerization inhibitor (36) lsopar G Exxon... 

All the cyanated phenols polymerize by a trimerization mechanism to give cyanurate ring systems ... 

Nicell JA, Saadi KW, Buchanan ID. Phenol polymerization and precipitation by horseradish peroxidase enzyme and an additive. Bioresour Technol 1995 54 5-16. 

The fluidized bed reactor has been used for phenol removal instead of fixed bed as most of the products formed are insoluble. The operation in packed bed reactors would lead to clogging phenomena and undesirable pressure drop [47, 88]. When deactivation of biocatalysts occurs and regeneration is needed, the liquid-solid circulating fluidized bed is a worthy alternative, as demonstrated for phenol polymerization [89]. The continuous enzymatic polymerization was carried out in a riser section and a downcomer was used for the regeneration of the coated immobilized particles. 

The different catalytic responses of peroxidase in dioxane and methanol versus acetone are intriguing. It is clear that the effects of water-miscible solvents on enzymatic catalysis are not equivalent and for the first time quantitative kinetic data have been obtained which highlight this. However, the cause of this effect remains unresolved. We are continuing and expanding this kinetic study to include other solvents, both water-miscible and immiscible, and other phenols. This future study will enable rational and quantitative approaches for peroxidase-catalyzed phenolic polymerizations to be based on optimal solvent and phenol choices. From a more fundamental standpoint, this work has shown that enzymes may be more active in organic media than in water as long as optimal conditions are employed. There is no reason to believe peroxidase is unique in this respect. 

Use Production of acetone and phenol polymerization catalyst, particularly in redox systems, used for rapid polymerization. 

There is a vast literature on phenol polymerization and this chapter will only review specific points of interests and recent progress in this field. 

More recently, Terzyk [32] also suggested that the irreversibility of phenol adsorption is due to the creation of strong complexes between phenol and surface carbonyl and lactone groups and to phenol polymerization. Salame and Bandosz [33] studied phenol adsorption at 30 and 60°C on oxidized and nonoxidized activated carbons. They concluded, from analyses of the isotherms by the FreundUch equation and the surface acidity of the carbons, that phenol was physisorbed by tt—tt dispersion interactions, whereas it was chemisorbed via ester formation between the OH group of phenol and surface carboxyl groups. 

Barrel volume may also influence the oxidative process. In this way, the favorable surface/volume ratio of 220 liters barrels may facilitate the phenolic polymerization. The four kinds of maturation effects which are attributed to barrels (evaporation, extraction, oxidation and component reaction) would all be intensified by a greater wood surface in contact with a unit of beverage (8). Although much of the literature focuses on the value of maturing wine in small oak barrels, many fine wines are aged in mid-size to large (more than 1000 liters) oak barrels (9). 

Clay particles formed before life began, so primordial soils had essentially the same chemical and physical characteristics as today s soils. Clays could adsorb and concentrate simple organic molecules as they fell in rain, or adsorb them directly from the atmosphere. Amino acids, for example, have been shown to polymerize when adsorbed on clay surfaces benzene and phenol polymerize spontaneously on Fe(III)- and Cu(lI)-coated clays. Whether such reactions actually led to the origin of life is speculation, but these reactions are much more likely in soils than in tidal pools. 

Uses Prod, of acetone and phenol polymerization catalyst/initiator/in-hibitor curing/crosslinking agent for unsat. polyester resins used in gel coats in food-pkg. adhesives polymerization catalyst in mfg. of paper/paperboard in contact with aq./fatty foods catalyst in food-con-tact crosslinked polyesters... 

The NMR spectrum of / -cresol show two doublets due to o- and m-protons at 6.75 and 7.0 ppm respectively (spectrum not shown). In addition new resonance peaks appeared in the 6.0 to 7.60 ppm range after first incremental addition of H2O2. In the subsequent spectra recorded after successive incremental addition of H2O2, the intensity of these new peaks increased resulting a con lex spectral pattern in the 6.60 to 7.30 ppm region. The nature of dimers and oligomers are identified with a similar approach that was adopted for phenol and p-sulfonated phenol polymerization. 

Horseradish peroxidase Trypsin (protease) Subtilisin (protease) Phenol polymerization Transpeptidation Ester hydrolysis Ethylacetate Butan-l,4-diol Dioxane, chloroform, etc. 

The contributions to wine character by native yeast fermentations are not restricted to flavor and bouquet. The extended lag phase before the onset of vigorous fermentation is likely, also important. As noted by Zoecklein et al. (1995), reaction of oxygen with anthocyanins and other phenols, in the absence of ethanol, is thought to enhance color stability (in resultant red wines) as well as accelerating phenol polymerization. 

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