Other Olefins

There are no detailed kinetic measurements on olefins other than those dealt with above, but there have been several investigations on the effects of olefin structure on polymerizability. For the most part these have 

The magnitude of the effects occasioned by changes in olefin structure are shown by the data in Table 18. 

This monomer has been studied using the VCl3/AlEt3 catalyst, which gives high trans 1,4 polymer [107] the reaction is accelerated by the addition of di-isopropylether. There is an acceleration of rate in the early stages to a steady value (R ) which fits the relationship 

J o is the initial rate, i t the rate and P, the yield of polymer after time t. 

This equation is consistent with the formation of new active centres (N ) according to 

The intramolecular cyclopropanation of the diazoesters 25-27 was catalyzed to produce the bicydic compounds up to 91% e.e. with 3, 9, and 10 [11]. The reaction of diazoketone 28 was catalyzed by 9 to produce the bicydic ketone 30 in 78% yield with 94% e.e. (Chart 7.4) [13]. 

In 1980, a ruthenium-catalyzed cyclopropanation with Ru2(OAc)4Cl was reported in comparison with rhodium, palladium, or copper [19]. Ru3(CO)i2 showed the catalytic activity for styrene and EDA at 60 °C [20]. In addition, Ru2(OAc)4 [21], Ru-polyethyl-ene carboxylates [22], ruthenacarborane clusters [23], Ru2(CO)4(M-OAc)2/n [24], and RuCl2(Ph3P)3 [25] catalyzed the cyclopropanation at 60-100 °C to give moderate to higher yields and 60 40 to 70 30 ratios of the trans cis isomers. 

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R = tert-Bu, R =R = H) in 10 mL Me2CH0H to give 29% PhCH2CH2COMe and 71% PhCH2CH2CH(OH)Me. AddnI. 39 catalysts were evaluated for the above oxidn. And 18 other olefins were oxidized ales, were obtained as byproducts. ... 

Olefin fibers, also called polyolefin fibers, are defined as manufactured fibers in which the fiber-forming substance is a synthetic polymer of at least 85 wt % ethylene, propjiene, or other olefin units (1). Several olefin polymers are capable of forming fibers, but only polypropylene [9003-07-0] (PP) and, to a much lesser extent, polyethylene [9002-88-4] (PE) are of practical importance. Olefin polymers are hydrophobic and resistant to most solvents. These properties impart resistance to staining, but cause the polymers to be essentially undyeable in an unmodified form. 

In the NTC region, back-bitiag reactioas appear to be respoasible for the formation of cycHc ethers (60,165—170). la additioa to oxetanes and tetrahydrofurans, tetrahydropyrans, oxiranes, and others are also observed (60,96,169) the tetrahydrofurans are favored. 0-Heterocycle yields of 25 to 30% have been reported for / -pentane (165,171). Conjugate and other olefins are also prominent products ia this regioa (60,169—172). 

Chemical Properties. Higher a-olefins are exceedingly reactive because their double bond provides the reactive site for catalytic activation as well as numerous radical and ionic reactions. These olefins also participate in additional reactions, such as oxidations, hydrogenation, double-bond isomerization, complex formation with transition-metal derivatives, polymerization, and copolymerization with other olefins in the presence of Ziegler-Natta, metallocene, and cationic catalysts. All olefins readily form peroxides by exposure to air. 

Conjugated Double Bonds. Sorbic acid is brominated faster than other olefinic acids (7). Reaction with hydrogen chloride gives predominately 5-chloro-3-hexenoic acid (8). 

HMD was originally produced by Du Pont as a coproduct in the manufacture of Qiana fiber. Du Pont subsequently sold the product to Bayer. In the 1990s MDA is hydrogenated by Air Products for Bayer (see Amines, aromatic-methylenedianiline). Commercial HMDI is a mixture of three stereoisomers. Semicommercial aUphatic diisocyanates include /n j -cyclohexane-l,4-diisocyanate (CHDI) and y -tetramethylxylylene diisocyanate (TMXDI). A coproduct in the production of TMXDI is y -isopropenyl-a,a-dimethylben2yl isocyanate (TMI), which can be copolymerized with other olefins to give aUphatic polyisocyanates. 

Butadiene can also be copolymerized with a large number of other olefins (224) and SO2 (225). 

Butadiene is also known to form mbbery polymers caused by polymerization initiators like free radicals or oxygen. Addition of antioxidants like TBC and the use of lower storage temperatures can substantially reduce fouling caused by these polymers. Butadiene and other olefins, such as isoprene, styrene, and chloroprene, also form so-called popcorn polymers (250). These popcorn polymers are hard, opaque, and porous. They have been reported to... 

This reaction proceeds through a chain mechanism. Free-radical additions to 1-butene, as in the case of HBr, RSH, and H2S to other olefins (19—21), can be expected to yield terminally substituted derivatives. Some polymerization reactions are also free-radical reactions. 

The selective oxidation is catalyzed by silver, which is the only good catalyst. Other olefins are not converted selectively to the epoxides in the presence of silver. However, propylene epoxidation is appHed commercially the catalysts are either molybdenum complexes in solution or soHd Ti02—Si02 (see... 

Catalytic reactions at somewhat lower temperatures also produce ethylene and other olefins. When coupled with a methane process to methyl chloride, this reaction results ia a new route to the light hydrocarbons that is of considerable interest. 

Carbon tetrachloride forms telomers with ethylene and certain other olefins (14—16). The mixture of Hquid products derived from ethylene telomerization may be represented CCl2(CH2CH2) Cl ia which nis 2l small number. Reaction of ethylene and carbon tetrachloride takes place under pressure and is induced by the presence of a peroxygen compound, eg, ben2oyl peroxide (17—19) or metal carbonyls (14,15). 

Until the mid-1950s the only polyolefins (polyalkenes) of commercial importance were polyethylene, polyisobutylene and isobutylene-isoprene copolymers (butyl rubber). Attempts to produce polymers from other olefins had, at best, resulted only in the preparation of low molecular weight material of no apparent commercial value. 

Experiments were earned out to investigate the transparency of various materials produced by copolymerising 4MP1 with other olefins such as but-1-ene, hex-l-ene and oct-l-ene. 

Many monomers have been copolymerised with ethylene using a variety of polymerisation systems, in some cases leading to commercial products. Copolymerisation of ethylene with other olefins leads to hydrocarbon polymers with reduced regularity and hence lower density, inferior mechanical properties, lower softening point and lower brittle point. 

In addition there is the possibility that other olefins may generate polymers with low Tg s which show little or no crystallinity at room temperature and are therefore potentially elastomeric. One commercial example is butyl rubber (designated HR), a copolymer of isobutene with a small amount of isoprene. 

Direct evidence for the existence of dichlorocarbene, by trapping with a suitable substrate, was obtained by Doering and Hoffmann in 1954. Dichlorocarbene was shown to add in a characteristic manner to the double bond of cyclohexene to give dichloronorcarane (1) in 59% yield similar adducts were obtained with other olefins. Bromo-form imderwent an analogous reaction in the presence of olefins to give... 

Other olefins that are commercially alkylated are isobutene and 1- and 2-butenes. Alkylation of isobutene produces mainly 2,2,4-trimethylpen-tane (isooctane). 

Other olefins applied in the hydroformylation process with subsequent hydrogenation are propylene trimer and tetramer for the production of decyl and tridecyl alcohols, respectively, and C7 olefins (from copolymers of C3 and C4 olefins) for isodecyl alcohol production. 

Less by-products generated from ethylene reactions with other compounds than from other olefins. 

Ethylene reacts by addition to many inexpensive reagents such as water, chlorine, hydrogen chloride, and oxygen to produce valuable chemicals. It can be initiated by free radicals or by coordination catalysts to produce polyethylene, the largest-volume thermoplastic polymer. It can also be copolymerized with other olefins producing polymers with improved properties. Eor example, when ethylene is polymerized with propylene, a thermoplastic elastomer is obtained. Eigure 7-1 illustrates the most important chemicals based on ethylene. 

The Wacker reaction can also be carried out for other olefins with terminal double bonds. With propene, for example, approximately 90% yield of acetone is obtained. 1-Butene gave approximately 80% yield of methyl ethyl ketone. 

Next step was to try to determine Kf values for other olefin-Br2 CTC s in order to check the structural effects on their stabilities. 

Products from very many other olefins have been detailed by Smidt et All monoolefins with at least one hydrogen atom on each carbon atom of the... 

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