Styrenes oxidations

Styrene is manufactured by alkylating benzene with ethene followed by dehydrogenation, or from petroleum reformate coproduction with propylene oxide. Styrene is used almost exclusively for the manufacture of polymers, of which the most important are polystyrene, ABS plastics and styrene-butadiene rubber. U.S. production 1980 3 megatonnes. 

Polylphenylene oxide) Styrene-ethylene block copolymer... 

Microbiological Oxidation. Styrene [100-42-5] can be oxidized to PEA by aerobic cultuting with a Pseudomonas bacterium ia the appropriate medium (101). Eor a medium containing peptone, (NH 2 04, Na2HP04 12H20, KH2PO4, MgSO and com steep Hquor, the yield is 2.34 mg/mL. 

See Butylenes Cimorohitcrins Ethylene oxide Olefins Propylene oxide Styrenes. 

Radicals also exhibit high activity in addition reactions. For example, the peroxyl radical of oxidizing styrene adds to the double bond of styrene with the rate constant k = 68 Lmol-1 s-1, and dioxygen adds with k = 5.6x 10-10Lmol-1 s-1 (298 K). As in the case of abstraction reactions, the distinction results from the fact that the first reaction is... 

This reaction was proposed by Farmer [44]. Miller and Mayo observed this reaction experimentally in oxidized styrene [45]. The rate constant of this reaction was measured by the free radical acceptor method by Denisova and Denisov [46]. This reaction is endothermic. The activation energies of these reactions are sufficiently higher than their enthalpy values. 

Intramolecular hydrogen bond is much stronger than the intermolecular hydrogen bond. The reactivity of such phenolic groups was studied by Pozdeeva et al. [51], Crown phenol A was synthesized, and the reactivity as chain terminating antioxidant in oxidized styrene (323 K) was studied. The chain terminating activity of this crown phenol A was compared with that of ionol. 

Kinetic Parameters of Peroxyl Radicals of Oxidized Styrene with Phosphites and their Complexes with CuCI in Chlorobenzene Solution [89]... 

In addition to the decay of hydroperoxides, metal complexes accelerate the reaction of phosphite with peroxyl radicals [90,91]. Phosphite forms a complex with the metal ion, and the formed complex terminates the chains more rapidly than phosphite does alone. For example, triphenyl phosphite terminates the chains in oxidized styrene with fkq = 2 x 103L mol-1 s-1 at T 393 K and the complex of this phosphite with CuCI does it with fkq = 2 x 105L mol-1 s 1, i.e., two orders of magnitude more rapidly. The values of / and kq for three phosphites and six complexes (phosphite with CuCI) are given in Table 17.10. 

A process plant inventories the following chemicals vinyl chloride, methyl ethyl ketone, ethylene oxide, styrene, and cyclohexane. Determine the hazards associated with these chemicals. What additional information might you request to perform an appropriate assessment of the risk associated with these chemicals ... 

Propylene oxide selectivity, 20 806-807 Propylene oxide vapors, 20 811 Propylene oxide-styrene (PO-SM)... 

Table 21. Solvent dependence of coupling constants in styrene oxide, styrene sulfide and 2,2-dichlorocyclopropylbenzene...

Sikov MR, Cannon WC, Carr DB. 1980. Teratologic assessment of butylene oxide, styrene oxide and methyl bromide. Report to National Institute for Occupational Safety and Health, Division of Biomedical and Behavioral Science, U.S. Department of Health, Education and Welfare, Cincinnati, OH, by Battelle, Pacific Northwest Laboratory, Richland, WA. NTIS No. PB81-168510. 

The dominant share of styrene production comes from dehydrogenation of EB in plants like that shown in Figure 8-5. Some comes as a coproduct in propylene oxide/styrene plants. An even smaller amount is recovered from the gasoline fraction of olefins plants cracking heavy liquids. 

Ethyl tert-butvl ether. Ethylene dibromide, Ethyl ether, Ethvl sulfide. 2-Heptanone, Methanol, 2-Methyl-1,3-butadiene, 2-Methvl-2-butene. Methyl chloride, Methylene chloride, Methyl iodide. Methyl mercaptan, 2-Methylphenol, Methyl sulfide. Monuron. Nitromethane, 2-Nitropropane, A-Nitrosodimethylamine, 1-Octene, 2-Pentanone, Propylene oxide, Styrene, Thiram, Toluene, Vinyl chloride, o-Xylene, tn-Xylene Formaldehyde cyanohydrin, see Acetontrile,... 

Sikov MR, Cannon WC, Carr DB Teratologic Assessment of Butylene Oxide, Styrene Oxide and Methyl Bromide. DHHS (NIOSH) Pub No 81-124. US Department of Health and Human Services, July 1981... 

The remarkably high isotope effects found in Reactions 10 and 10a are almost as embarrassing as was our discovery of an isotope effect of about 15 in the reaction with phenols referred to above. [For 2,6-di-tert-butyl-4-methylphenol in oxidizing styrene at 65°C. we obtained an isotope effect kH/kD = 10.6 (11). We have since carefully measured the isotope effect for 2,4,6-tri-ferf-butylphenol under the same conditions and have obtained a value 15. In these cases, hydrogen bonding to the solvent is relatively unimportant (6, 12). Similarly, DaRooge and Mahoney (9) have reported that for the reaction of 2,4,6-tri-tert-butylphenoxy radicals with 4-phenylphenol kH/kD 7.5.] Although... 

EB/SM (ethylbenzene/styrene monomer) process. Styrene can also be made by PO/SM (propylene oxide/styrene monomer) process). This process starts by oxidizing ethylbenzene (C6H5CH2CH2) to its hydroperoxide (C6H5CH(OOH)CH3), which is then used to oxidize propylene (CH3CH = CH2) to produce propylene oxide (CH3CH2CHO) and phenylethanol (C6H5CH(OH)CH3). The phenylethanol is then dehydrated to give... 

Sikov, M.R., Cannon, W.C., Carr, D.B., Miller, R.A., Montgomery, L.F. Phelps, D.W. (1981) Teratologic Assessment of Butylene Oxide, Styrene Oxide and Methyl Bromide, Cincinnati, OH, United States Department of Health and Hrunan Services, Public Health Service, Centers for Disease Control, National Instute for Occupational Safety and Health... 

Because (Co.La)salen is immobilized on the mesopore wall of MCM-41,it is anticipated that this catalyst would exhibit high stability for catalyst recycling. Therefore, the (Co.La)salen/MCM-41 sample was recovered by filtration and used again for oxidation of styrene. The activities for (Co,La)salen/MCM-41 for two successive oxidation of styrene are listed in table 3. The catalytic activity obtained for the second run is over 90% of that for the first run. This result indicates that (Co,La)salen is firmly immobilized in MCM-41 and has high stability in oxidation styrene. 

Several 2-thienylaodiums have likewise been treated, with epoxides to obtain the corresponding 2-( -hydroryalkyl)thiophene (Eq. 801. Among the epoxides examined in this connexion are ethylene oxide, propylene oxide, styrene oxide, 1, 2-epoxy-3-butene, and. epichloro-hydrin ... 

Anderaaon 0 has determined pseudo finat-order rate constants for the reaction of exoees ammonia with a variety of epoxides, ranging from ethylene oxide itself to tefcramethylethylen oxide, and including also oyolohexene oxide, styrene oxide, and glyoidol. The least reactive substance studied, tetramethylethylenc oxide, was found to react 600 times more slowly than ethylene oxide. Curiously enough, on the other hand, glyoidol, styrene oxide, and ethylene oxide all roar ted at comparable rates. 

Petere and Kh rash had previously described the reaction of 2,4-(linitrophenylaulfenyl chloride with ethylene oxide in pyridine. 551 Although propylene oxide, styrene oxidB, and eyolohexene oxide likewise underwent addition (Eqs. 935 and 936J, cis- and Iranj-stilbene oxide wore inert under the same conditions. 

Alkenes can be transformed into ketones by Wacker oxidation (Entry 2, Table 12.3), but this reaction does not seem to proceed cleanly on polymeric supports. Janda and co-workers were able to oxidize styrenes bound to macroporous polystyrene to the corresponding acetophenones, but reported that the reaction did not proceed on PEG... 

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