Styrene oxide applications

At least three methods have been found to be applicable to the solubilization of chemically modified wood. The first experiment (4) (Direct method) employed severe dissolution conditions. For example, in 20-150 min at 200-250°C, wood samples esterified by a series of aliphatic acids could be dissolved in benzyl ether, styrene oxide, phenol, resorcinol, ben-zaldehyde, aqueous phenol solutions, etc. For carboxymethylated, ally-lated and hydroxyethylated woods, the conditions provided for dissolution in phenol, resorcinol or their aqueous solutions, formalin, etc., by standing or stirring at 170°C for 30 to 60 min (5). 

Application of Raney Nickel to measure adducts of styrene oxide with hemoglobine and albumin. Chem. Res. Toxicol., 6, 238-244... 

Styrene, one of the world s major organic chemicals, is derived from ethylene via ethylbenzene. Several recent developments have occurred with respect to this use for ethylene. One is the production of styrene as a co-product of the propylene oxide process developed by Halcon International (12). In this process, benzene is alkylated with ethylene to ethylbenzene, and the latter is oxidized to ethylbenzene hydroperoxide. This hydroperoxide, in the presence of suitable catalysts, can convert a broad range of olefins to their corresponding oxirane compounds, of which propylene oxide presently has the greatest industrial importance. The ethylbenzene hydroperoxide is converted simultaneously to methylphenyl-carbinol which, upon dehydration, yields styrene. Commercial application of this new development in the use of ethylene will be demonstrated in a plant in Spain in the near future. 

Yamamoto has reported that ytterbium triisopropoxide, prepared in situ from Yb(OTf)3 and LiOPr in THF, can be used in a very mild, highly efficient, and widely applicable procedure for the azidolysis of epoxides. In every case except styrene oxide, products are derived from the attack of azide at the less hindered carbon atom. The method appears to be quite tolerant of functionality, leaving preexisting tosyl, acyl, and siloxy groups intact (e.g.,... 

The use of SSL or lignosulphonates in other polymeric adhesive systems has also been examined [e.g., with polyacrylamide, proteins/aldehydes, polyethylene oxide, polyethylene imine, epoxides, melamine, styrene oxide, polyisocyanates (55)]. So far, these procedures, for different reasons, have not led to any major practical application (36). It would, however, be interesting to reexamine some of these processes using not crude spent sulphite liquors, but instead those purified by membrane filtration. 

The use of a higher substrate concentration for a given amount of enzyme is also a very important goal for preparative scale applications. Such an achievement has been successful very recently [213]. Thus, a two-liquid-phase process allowing for the preparative scale resolution ofpara-bromo styrene oxide (6 g,... 

When using conventional homogeneous Lewis or Br0nsted acidic catalysts only liquid-phase reactions are applicable. With heterogeneous catalysts gas-phase reactions, which are readily performed continuously, can also be realized. The product is readily separated from the catalyst and higher efficiency is usually achieved (space-time yield). The rearrangement of styrene oxides in the gas phase described later in this section [8,15,16] is an example of the improvement of yields by changing the reactor concept from liquid- to gas-phase. 

Olefin epoxidation is not only important in the manufacture of bulk chemicals, e. g. ethylene and propylene oxides, but is also a widely used transformation in the fine-chemicals industry [1], Ethylene oxide is manufactured by vapor-phase oxidation of ethylene, with air or oxygen, over a supported silver catalyst [2], This method is not generally applicable as olefins containing allylic or other reactive C-H bonds give complex mixtures of products with low epoxide selectivity. The method has recently been extended to some other olefins that do not contain reactive allylic C-H bonds, e. g. butadiene, styrene, norbornene, and tert-butyl ethylene [3]. Some of these products, e. g. butadiene monoepoxide and styrene oxide, have potential applications as fine chemicals/intermediates. 

Beilstein Handbook Reference) AI3-17104 BRN 2302822 CCRIS 7052 Di-(2-ethylhexyl) terephthalate EINECS 229-176-9 HSDB 6150 Kodaflex DOTP Terephthalic acid, bis(2-ethylhexyl) ester. Plasticizer used with PVC resins, in PVC plastisols, rubber application including wire coatings, ajtomotive and furniture upholstery compatible with acrylics, CAB, cellulose nitrate, polyvinyl butyral, styrene, oxidizing alkyds, nitrile rubber. Solid mp = 30-34° bp = 400 d = 0.980. Eastman Chem. Co. 

K. Ito, Syntheses of poly(ethylene oxide-b-styrene oxide) macromonomers and their application to emulsion and dispersion copolymerization with styrene, Polym. ]. (Tokyo) 2003, 35, 528-534. 

Scheme11.4 Applications of chiral styrene oxides and 1,2-diol monotosylates to the synthesis of some chiral drugs.

Catalytic membranes brought new and attractive applications of metal-incorporated mesoporous materials. Mesoporous nickel-silicate membranes were used as efficient catalysts in the selective oxidation of styrene to epoxy ethyl benzene and benzene to phenol. The use of membranes also offered a very good possibility to control the hydrogen peroxide feed and the selectivity in oxidation of styrene to styrene oxide and to increase the reaction rate. The effect of the H2O2 permeance on the conversion of styrene and benzene was also evidenced [83]. The conversion of styrene with membrane reactor has been compared with that realized in a conventional batch reactor with powdery catalyst indicating superior results. 

As noted above, when Al-porphyrin complexes [97] or Zn compounds [98] are used as catalysts for the carboxylation of epoxides, the formation of polymers is observed. A1 catalysts are now used in a plant in China. The mechanism of the polymerization reaction has been studied and the most credited mechanism when Zn compounds are used is shown in Scheme 1.12. The molecular mass of the polymers varies with the catalyst. Primarily propene oxide and styrene oxide have been used so far, with some interesting applications of cyclohexene oxide. It is wished to enlarge the use of substrates in order to discover new properties of the polymers. 

Applications that have been tested with good results are cases where nitrous oxide has been the air contaminant of current interest or used as a tracer gas. Other applications have been carbon disulfide in a rayon factory and styrene vapor, one of the volatile components from a surface-coating material. 

An interesting application of this reaction was the use of macro-molecular anhydrides, namely, styrene-maleic anhydride or vinyl acetate-maleic anhydride copolymers in the presence of perchloric acid as catalyst, these copolymers acylate mesityl oxide or d rpnone to macromolecular pyrylium salts which, with aryl substituents, are fluorescent.No crystalline products could be obtained from succinic anhydride because of the solubility and ease of decarboxylation. 

Phenylene oxide Based (PPO) plastic that is a choice for electrical applications, housings for computers and appliances, both neat and in structural foam form. It has superior dimensional stability, moisture resistance due to styrene components, which, however, cause some sacrifice of weather and chemical resistance. Use includes automobile wheel covers, pool plumbing, consumer electronic external and internal components. 

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