Phenyl hydroquinone

For fiber studies polyester BB1 was chosen. A method to measure birefringence developed by Yang and co-workers (18) was applied on polymer BB1 fibers and showed no dependence on DR, but remained constant 0.32 within experimental error. Similar observations were made by McIntyre and co-workers with a somewhat similar LC co-polyester with chloro instead of phenyl-hydroquinone and 25 mol% 4,4 -dicarboxydiphenylether (13). 

Table 25 PEI copolymers of n-carboxyphenyl trimellitimide, isophthalic acid and phenyl-hydroquinone...

Okubo, T., F. Nagai, T. Seto, et al. 2000. The inhibition of phenyl-hydroquinone-induced oxidative DNA cleavage by constituents of Moutan Cortex and Paeoniae Radix. Biol. Pharm. Bull. 23(2) 199-203. 

Fluorinated phenyl groups in the side chain can be introduced by using 4-(fluorophenyl)hydroquinone and 3,4-difluoro phenyl hydroquinone as monomers [82], The introduction of these monomers results in highly soluble PEEK polymers with low dielectric constants. The synthesis is shown exemplarily in Figure 6.10. 

For the wholly aromatic TLCPs derived from TA, phenyl hydroquinone, and 3,4 -dicarboxyl phenylether [59], the thermal stability measured by TGA slightly decreases with the increasing ether content. All polymers exhibit good thermal stability up to about 400°C in N2 and 25°C lower in air, with a 20°C min heating rate. The thermal stability of the TLCPs decreases when the phenyl hydroquinone is replaced by (1-phenylethyl) hydroquinone. 

N. Khan, Z. Bashir, and D. M. Price, Liquid crystalline aromatic polyesters formed with terephthalic acid, phenyl hydroquinone, and naphthalene or anthracene diols. Journal ( Applied Polymer Science, 58,1509 (1995). 

Nematic polyurethanes derived from 4,4 -dihydroxybiphenyl and 4,4 -bipiperidine, ethylene-4,4 -bipiperidine, or trimethylene-4,4 -bipiperidine have been reported [254]. 4,4 -Bipiperidine, l,2-bis(4-piperidinyl)ethane, and l,3-bis(4-piperidinyl)pro-pane were condensed with the dichloroformates of p-phenylene, 2-methyl-l,4-phenylene, or 2,5-biphenylylene. Furthermore, two copolyurethanes were prepared either by mixing 4,4 -bipiperidine and l,2-bis(4-piperidinyl)ethane or by mixing the dichloroformates of p-phenylene and 2,5-biphenylene. The polyurethanes derived from hydroquinone or methylhydroquinone were semicrystalline polymers with a short-term thermostability up to 310 °C. The polyurethanes derived from phenyl-hydroquinone were amorphous with a thermostability up to 360 °C. The homo-and co-polyurethanes containing 4,4 -biphenylylene units formed a smectic layer structure in the solid state and a nematic melt above the melting point [254]. 

A new double adamantyl-substituted aromatic bisphenol monomer, 4,8-bis (l-adamantly)-l,5-dihydroxynaphthalene (AdNp) was successfully S5mthesized via the Friedel-Crafts reaction as depicted Scheme 10.11, and two new PAEKs containing adamantly groups (Ad-PAENKs) were synthesized based on the new monomer of AdNp, (3-trifluoromethyl)phenyl hydroquinone (3FHQ) and 4,4 -difluorobenzophenone (D ) via the nucleophilic aromatic substitution polymerization as depicted Scheme 10.12. 

Researchers at Du Pont used hydroquinone asymmetrically substituted with chloro, methyl, or phenyl substituents and swivel or nonlinear bent substituted phenyl molecules such as 3,4- or 4,4 -disubstituted diphenyl ether, sulfide, or ketone monomers. Eor example,... 

However, the vast majority of research has been devoted to synthesis involving electrophilic substitution on the aromatic ring of hydroquinone. Hence, phenylhydroquinone can be obtained by the reaction of phenyl dia onium salts (18) with hydroquinone (82). 

Sulfation by sulfamic acid has been used ia the preparation of detergents from dodecyl, oleyl, and other higher alcohols. It is also used ia sulfating phenols and phenol—ethylene oxide condensation products. Secondary alcohols react ia the presence of an amide catalyst, eg, acetamide or urea (24). Pyridine has also been used. Tertiary alcohols do not react. Reactions with phenols yield phenyl ammonium sulfates. These reactions iaclude those of naphthols, cresol, anisole, anethole, pyrocatechol, and hydroquinone. Ammonium aryl sulfates are formed as iatermediates and sulfonates are formed by subsequent rearrangement (25,26). 

Sulfuric acid is also a very satisfactory catalyst aluminum alkoxides also are useful, especially when the alcohols would be adversely affected by strong acids. Sodium alkoxides produce undesirable side reactions and give lower yields. When alkaline catalysts are employed, an alkaline polymerization inhibitor, such as j j-phenylenediamine or phenyl-d-naphthylamine, should be used instead of hydroquinone. 

Lithiochloromethyl phenyl sulfoxide 99 was found to react with aryl or alkyl halides in the presence of one equivalent of hexamethylphosphoramide to afford alkylated products 100 in high yields135. Thermal decomposition of these products in the presence of a catalytic amount of hydroquinone in xylene gave the corresponding vinyl compounds 101. 

Efforts to achieve a retardation of cross-linking in elastomers are based on the general assumption of a radical mechanism for retardation cross-linking and the possibility of its inhibition by a deactivation of the reactive macromolecular radical [33]. These compounds generally contain one or more labile hydrogen atoms, which after, donation of this atom, will form relatively inactive radicals. Typical antirad agents are quinones, hydroquinones, and aromatic amines (phenyl and napthylamines). 

As for the relevant application, recently, a specific photochromic compound, 1,2-bis(2 -methyl-5 -phenyl-3 -thienyl)perfluorocyclopentene (BP-BTE), and the analogs of HBO, 2,5-bis(5,-0 rt-butyl-benzooxazol-2 -yl)hydroquinone (DHBO), were employed in the high-contrast, reversible, photochromic switching of fluorescence emission and its perfect nondestructive readout (Fig. 14). Due to the large... 

To avoid inadvertent degradation of this kind during isolation and fractionation of the starch, an oxygen-free atmosphere appears essential. Perhaps the use of an oxidation inhibitor (for example, hydroquinone, quinol, or V-phenyl-2-naphthylamine) would also be suitable. 

The monomers studied, 2-hydroxyethyl methacrylate (HEMA) and diethylene glycol dimethacrylate (DEGDMA), were obtained from Aldrich (Milwaukee, WI) and Polysciences, Inc. (Warrington, PA), respectively, and were used after dehibition to remove the hydroquinone inhibitor. 2,2-Dimethoxy-2-phenyl acetophenone (DMPA), the conventional initiator used in this study, was obtained from Ciba-Geigy (Hawthorne, NY) and the tetraethylthiuram disufide (TED) was obtained from Aldrich. 

AI3-00040, see Cyclohexanol AI3-00041, see Cyclohexanone AI3-00045, see Diacetone alcohol AI3-00046, see Isophorone AI3-00050, see 1,4-Dichlorobenzene AI3-00052, see Trichloroethylene AI3-00053, see 1,2-Dichlorobenzene AI3-00054, see Acrylonitrile AI3-00072, see Hydroquinone AI3-00075, see p-Chloro-rrr-cresol AI3-00078, see 2,4-Dichlorophenol AI3-00085, see 1-Naphthylamine AI3-00100, see Nitroethane AI3-00105, see Anthracene AI3-00109, see 2-Nitropropane AI3-00111, see Nitromethane AI3-00118, see ferf-Butylbenzene AI3-00119, see Butylbenzene AI3-00121, see sec-Butylbenzene AI3-00124, see 4-Aminobiphenyl AI3-00128, see Acenaphthene AI3-00134, see Pentachlorophenol AI3-00137, see 2-Methylphenol AI3-00140, see Benzidine AI3-00142, see 2,4,6-Trichlorophenol AI3-00150, see 4-Methylphenol AI3-00154, see 4,6-Dinitro-o-cresol AI3-00262, see Dimethyl phthalate AI3-00278, see Naphthalene AI3-00283, see Di-rj-butyl phthalate AI3-00327, see Acetonitrile AI3-00329, see Diethyl phthalate AI3-00399, see Tributyl phosphate AI3-00404, see Ethyl acetate AI3-00405, see 1-Butanol AI3-00406, see Butyl acetate AI3-00407, see Ethyl formate AI3-00408, see Methyl formate AI3-00409, see Methanol AI3-00520, see Tri-ocresyl phosphate AI3-00576, see Isoamyl acetate AI3-00633, see Hexachloroethane AI3-00635, see 4-Nitrobiphenyl AI3-00698, see IV-Nitrosodiphenylamine AI3-00710, see p-Phenylenediamine AI3-00749, see Phenyl ether AI3-00790, see Phenanthrene AI3-00808, see Benzene AI3-00867, see Chrysene AI3-00987, see Thiram AI3-01021, see 4-Chlorophenyl phenyl ether AI3-01055, see 1.4-Dioxane AI3-01171, see Furfuryl alcohol AI3-01229, see 4-Methyl-2-pentanone AI3-01230, see 2-Heptanone AI3-01231, see Morpholine AI3-01236, see 2-Ethoxyethanol AI3-01238, see Acetone AI3-01239, see Nitrobenzene AI3-01240, see I idine AI3-01256, see Decahydronaphthalene AI3-01288, see ferf-Butyl alcohol AI3-01445, see Bis(2-chloroethoxy)methane AI3-01501, see 2,4-Toluene diisocyanate AI3-01506, see p,p -DDT AI3-01535, see 2,4-Dinitrophenol AI3-01537, see 2-Chloronaphthalene... 

Hydroxyphenol, see Hydroquinone p-Hydroxyphenol, see Hydroquinone 4-Hydroxy-3-(l-phenyl-3-oxobutyl)coumarin, see Warfarin 1 -Hydroxypropane, see 1 -Propanol 3 Hydroxypropene, see Allyl alcohol 3 Hydroxypropionic acid lactone, see p-Propiolactone... 

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