Styrenes ethylene derivs

For the addition of ethylene, EtOAc as solvent was particularly advantageous and gave 418 in 60% yield (Scheme 6.86). The monosubstituted ethylenes 1-hexene, vinylcyclohexane, allyltrimethylsilane, allyl alcohol, ethyl vinyl ether, vinyl acetate and N-vinyl-2-pyrrolidone furnished [2 + 2]-cycloadducts of the type 419 in yields of 54—100%. Mixtures of [2 + 2]-cycloadducts of the types 419 and 420 were formed with vinylcyclopropane, styrene and derivatives substituted at the phenyl group, acrylonitrile, methyl acrylate and phenyl vinyl thioether (yields of 56-76%), in which the diastereomers 419 predominated up to a ratio of 2.5 1 except in the case of the styrenes, where this ratio was 1 1. The Hammett p value for the addition of the styrenes to 417 turned out to be -0.54, suggesting that there is little charge separation in the transition state [155]. In the case of 6, the p value was determined as +0.79 (see Section 6.3.1) and indicates a slight polarization in the opposite direction. This astounding variety of substrates for 417 is contrasted by only a few monosubstituted ethylenes whose addition products with 417 could not be observed or were formed in only small amounts phenyl vinyl ether, vinyl bromide, (perfluorobutyl)-ethylene, phenyl vinyl sulfoxide and sulfone, methyl vinyl ketone and the vinylpyri-dines. 

The chemical uses for ethylene prior to World War II were limited, for the most part, to ethylene glycol and ethyl alcohol. After the war, the demand for styrene and polyethylene took off, stimulating ethylene production and olefin plant construction. Todays list of chemical applications for ethylene reads like the WTiat s What of petrochemicals polyethylene, ethylbenzene (a precursor to styrene), ethylene dichloride, vinyl chloride, ethylene oxide, ethylene glycol, ethyl alcohol, vinyl acetate, alpha olefins, and linear alcohols are some of the more commercial derivatives of ethylene. The consumer products derived from these chemicals are found everywhere, from soap to construction materials to plastic products to synthetic motor oils. 

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... 

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... 

This reaction is applied to a wide range of alkenes such as acrylic esters, styrene, ethylene, 1-alkene, 1,3-dienes, allyl chloride, allyl acetate, and vinyl ethers [122]. Tolerance of the arylmercury compounds to polar functional groups in the substrate renders the reaction applicable to the synthesis of many functionalized styrene derivatives. A ferrocenyl mercury compound undergoes addition to alkene via the Heck type reaction of methyl methacrylate (Eq. 5.29) [123]. 

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). 

Benzene is alkylated with ethylene to produce ethylbenzene, which is then dehydrogenated to styrene, the most important chemical iatermediate derived from benzene. Styrene is a raw material for the production of polystyrene and styrene copolymers such as ABS and SAN. Ethylbenzene accounted for nearly 52% of benzene consumption ia 1988. 

A large number of pyridazines are synthetically available from [44-2] cycloaddition reactions. In one general method, azo or diazo compounds are used as dienophiles, and a second approach is based on the reaction between 1,2,4,5-tetrazines and various unsaturated compounds. The most useful azo dienophile is a dialkyl azodicarboxylate which reacts with appropriate dienes to give reduced pyridazines and cinnolines (Scheme 89). With highly substituted dienes the normal cycloaddition reaction is prevented, and, if the ethylenic group in styrenes is substituted with aryl groups, indoles are formed preferentially. The cycloadduct with 2,3-pentadienal acetal is a tetrahydropyridazine derivative which has been used for the preparation of 2,5-diamino-2,5-dideoxyribose (80LA1307). 

Thermoplastic block copolymers were used for pressure-sensitive and hot-melt rubber adhesives as from the middle sixties. These adhesives found application in packaging, disposable diapers, labels and tapes, among other industrial markets. The formulation of these adhesives generally includes an elastomer (generally containing styrene endblocks and either isoprene, butadiene or ethylene-butylene midblocks) and a tackifier (mainly a rosin derivative or hydrocarbon resin). 

A dispersant that can be used in drilling fluids, spacer fluids, cement slurries, completion fluids, and mixtures of drilling fluids and cement slurries controls the rheologic properties of and enhances the filtrate control in these fluids. The dispersant consists of polymers derived from monomeric residues, including low-molecular-weight olefins that may be sulfonated or phosphonated, unsaturated dicarboxylic acids, ethylenically unsaturated anhydrides, unsaturated aliphatic monocarboxylic acids, vinyl alcohols and diols, and sulfonated or phosphonated styrene. The sulfonic acid, phosphonic acid, and carboxylic acid groups on the polymers may be present in neutralized form as alkali metal or ammonium salts [192,193]. 

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