Ethylene derivatives styrene

Ethylene and styrene derivatives react with various propargylic silyl ethers in the presence of zirconocene(II) to afford allenic products in high yield (Scheme 5.7). For example, substrate 67 was transformed into the trisubstituted allene hydrocarbon 68 in 93% yield under the reaction conditions [20]. In the synthesis of various tetraalkylated allenes, in which several of the alkyl substituents also contained triple bonds, allowing these substrates to be cydized intramolecularly into aromatic com-... 

Beside the homopolymerization of BD Nd-based Ziegler/Natta catalyst systems are also applied for the homopolymerization of IP, the copolymerization of the dienes BD and IP, the homopolymerization and copolymerization of substituted dienes as well as for the copolymerization of BD with alkenes such as styrene, ethylene and other ethylene derivatives. 

Of great importance are the ethylene derivatives with aromatic substituents. Styrene (vinylbenzene) is one of the monomers produced industrially in large volume. Polystyrene and styrene copolymers still belong to the important representatives of modern plastics and rubbers. Styrene can be polymerized by any of the known procedures. It has suitable physical properties, and therefore it is one of the most frequently studied monomers. It also... 

Several series of mono-aryloxo and bis-aryloxo titanium derivatives have been prepared by the routes outlined in Scheme 349. Activated by MAO the compounds are used as efficient catalysts for the syndiospecific polymerization of styrene and the co-polymerization of ethylene and styrene. The molecular structures of some of these compounds have been determined by X-ray diffraction. The Ti-O-C bond angle in the structure of Cp TiCl2(0-2,6-Pr12C6H3) differs significantly from those that are observed for the other structures. The effect of the substituents, both on the Cp ring and the alkoxo group, plays an essential role for the catalytic activity and the properties of the polymer obtained.578,779,837-847... 

The polymerization of ethylene derivatives has recently become extremely important for the manufacture of plastics. Certain substituents in ethylene — those that increase the polarization — increase both the extent and the rate of polymerization. Such substituents are aromatic groups (as in styrene), oxygen-containing groups (as in acrolein, acrylic esters, and vinyl esters and ethers), and halogens (as in vinyl chloride). Multiplication of these substituents, however, depresses or completely suppresses the tendency to polymerize for instance, stilbene gives only a dimer when illuminated in benzene.14... 

Since the polymerization of ethylene derivatives, particularly styrene, has been studied most exhaustively from the kinetic standpoint, it may suffice for the purpose of the present work to confine ourselves to this case and to cite it as exemplifying the treatment of a polymerization reaction. 

A mixture of 3,6-diphenyl-si/m-tetrazine, diphenylacetylene, and toluene refluxed 3 days 3,4,5,6-tetraphenylpyridazine. Y 86%.—A variety of unsatd. compounds, inch aliphatic and alicyclic olefins, styrenes, acetylenes, butadienes, and allene give the above reaction. 3,6-Bis(polyfluoroalkyl)-sym-tetrazines react with particular ease. F. e., also from ethylene derivatives via 1,4-dihydropyridazines, s. R. A. Garboni and R. V. Lindsey, Jr., Am. Soc. 81, 4342 (1959). 

It is well accepted that the superior properties of Nafion membranes result from a phase separation between the hydrophobic perlluorinated polymer backbone and the sulfonic acid bearing side-chains. This phase separation leads to the formation of ion-conducting channels in the nm-range. Also ion-exchange membranes derived from sulfonated styrene-ethylene/butylene-styrene triblock copolymers (s-SEBS) exhibit a phase-separated morphology, which led to proton conductivities similar to Nafion but with a much lower methanol crossover [178]. 

Soon after commercialization of ethylene glycol and TEL came a whole stream of ethylene derivatives such as styrene and polyethylene. Other major compounds made available from the cracking of liquid petroleum were the elastomers, synthetic fabrics, and the plastics,... 

Acrylics. Acetone is converted via the intermediate acetone cyanohydrin to the monomer methyl methacrylate (MMA) [80-62-6]. The MMA is polymerized to poly(methyl methacrylate) (PMMA) to make the familiar clear acryUc sheet. PMMA is also used in mol ding and extmsion powders. Hydrolysis of acetone cyanohydrin gives methacrylic acid (MAA), a monomer which goes direcdy into acryUc latexes, carboxylated styrene—butadiene polymers, or ethylene—MAA ionomers. As part of the methacrylic stmcture, acetone is found in the following major end use products acryUc sheet mol ding resins, impact modifiers and processing aids, acryUc film, ABS and polyester resin modifiers, surface coatings, acryUc lacquers, emulsion polymers, petroleum chemicals, and various copolymers (see METHACRYLIC ACID AND DERIVATIVES METHACRYLIC POLYMERS). 

Polyall lene Oxide Block Copolymers. The higher alkylene oxides derived from propjiene, butylene, styrene (qv), and cyclohexene react with active oxygens in a manner analogous to the reaction of ethylene oxide. Because the hydrophilic oxygen constitutes a smaller proportion of these molecules, the net effect is that the oxides, unlike ethylene oxide, are hydrophobic. The higher oxides are not used commercially as surfactant raw materials except for minor quantities that are employed as chain terminators in polyoxyethylene surfactants to lower the foaming tendency. The hydrophobic nature of propylene oxide units, —CH(CH2)CH20—, has been utilized in several ways in the manufacture of surfactants. Manufacture, properties, and uses of poly(oxyethylene- (9-oxypropylene) have been reviewed (98). 

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