Butene-propylene

Several peaks arising from different pentad and hexad comonomer sequences have been observed n the C-NMR spectrum of stereoregular 1-butene-propylene copolymers. The paper by Aoki and co-workers [54] demonstrated that the analytical method based on the two-dimensional (2D)-INADEQUATE spectrum and the chemical shift calculation via the y-effect is very powerful for the assignment of C-NMR spectra of higher a-olefin copolymers. A stereoregular 1-butene-propylene copolymer is a suitable example because reliable assignments have been proposed by a reaction probability model [55]. 

In the region of the methyl carbon in the propylene unit (21.4 ppm to 22.0 ppm), the side-chain methylene carbon in the 1-butene unit (27.5 ppm to 28.5 ppm), and the central methylene carbon of the PP diad (46.5 ppm to 47.5 ppm), the peaks arising from different comonomers sequences longer than pentad are observed. To provide assignments of these peaks, chemical shift differences among pentad and hexad comonomers sequences were calculated by the y-effect method. Table 5.6 shows the calculated chemical shift differences in the resonance regions of methyl and methylene carbons in 1-butene-propylene copolymer  

Planar zig-zag conformation of 1-butene-propylene copolymer methane resonance regions were excluded because of their low spectral resolution. 

A Methyl carbon of propylene B Central methylene carbon of a polypropylene diad C Side chain methylene carbon of 1-butene among propylene units. Reproduced with permission from A. Aoki, T. Hayashi and T. Asakura, Macromolecules, 1992, 

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Monoolefinic Hydwcarbons Ethylene Propylene 1 -Butene 1-Butane cis-2-Biitene trans-2-Biitene... 

A scandium complex, Cp ScH, also polymerizes ethylene, but does not polymerize propylene and isobutene [125]. On the other hand, a linked amidocyclo-pentadienyl complex [ Me2Si( / 5-C5 Me4)( /1 -NCMe3) Sc(H)(PMe3)] 2 slowly polymerizes propylene, 1-butene, and 1-pentene to yield atactic polymers with low molecular weight (Mn = 3000-7000) [126, 115]. A chiral, C2-symmetric ansa-metallocene complex of yttrium, [rac-Me2Si(C5H2SiMe3-2-Buf-4)2YH]2, polymerizes propylene, 1-butene, 1-pentene, and 1-hexene slowly over a period of several days at 25°C to afford isotactic polymers with modest molecular weight [114]. 

Ethylene can be copolymerised with several monomers like propylene, 1-butene, vinyl acetate, ethyl acrylate, etc. 

He was a Professor of Industrial Chemistry, School of Engineering, Polytechnic Institute of Milan, Milan, Italy since 1937. He became involved with applied research, which led to the production of synthetic rubber in Italy, at the Institute in 1938. He was also interested in the synthesis of petrochemicals such as butadiene and, later, oxo alcohols. At the same time he made important contributions to the understanding of the kinetics of some catalytic processes in both the heterogeneous (methanol synthesis) and homogeneous (oxosynthesis) phase. In 1950, as a result of his interest in petrochemistry, he initiated the research on the use of simple olefins for the synthesis of high polymers. This work led to the discovery, in 1954, of stereospecific polymerization. In this type of polymerization nonsymmetric monomers (e.g., propylene, 1-butene, etc.) produce linear high polymers with a stereoregular structure. 

Pd/Cu zeolite Y associations were found to be selective catalysts for oxidation of olefins in the presence of steam at temperatures ranging from 373 to 433K [22-30]. Acetone and acetaldehyde were obtained by propylene and ethylene oxidation, with selectivities of at least 90%. Neither Pd/Y nor Cu/Y showed good activity in these reactions. The conversion of different olefins under the same experimental conditions decreases in the following order [23] ethylene > propylene > 1-butene > cis-2-butene - trans-2-butene. 

Ethylene is conveniently polymerized in the laboratory at atmospheric pressure using a titanium-based coordination catalyst [34]. It may also be polymerized less conveniently in the laboratory under high pressures using free radical catalysts at high and low temperatures [35-37]. Other olefins such as propylene, 1-butene, or 1-pentene homopolymerize free radically only to low molecular weight polymers and require ionic or coordination catalysts to afford high molecu-... 

Ionic copolymers are composed from an a-olefin with an olefin content of 80 mol-% and an ethylenically unsaturated carboxylic acid (6). Suitable olefins include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, etc. 

The diffusional activation energies, listed in Table III, show a clear correlation with the critical diameters of the sorbite molecules (calculated as the diameter of the smallest cylinder which cap circumscribe the molecule). The data for the olefins are of particular interest since propylene, 1-butene, and frcms-2-butene, which all have the same critical diameter,... 

Reference has already been made to the addition of chromyl chloride to olefins, which gives abnormal halohydrins 72 Propylene, 1-butene, 1-pentone, and 1-hexene, for example, all yield primary alcohols, as shown in Eq. (141). 

Bromofluorination 2 followed by the present procedure is a general way to convert 1 alkenes to 2-fluoroaIkanoic acids similar results have been obtained with ethylene, propylene, 1-butene, 1-hexene, 1-octene, 1-decene, and methyl 10-unde-cenoate.5 It is an easy and convenient way to make 2-fluoroalka-noic acids, for it requires only conventional apparatus and readily available intermediates. 

Vaughan et al. (103) studied the photobromination of ethylene, propylene, 1-butene, isobutene, and vinyl chloride in the gas phase and found in every case where a distinction could be made that the product was almost entirely the so-called abnormal addition product in terms of the Markownikoff s rule. However, the more recent work of Skell et al. (95) shows that 2-bromo-w-propyl radical may rearrange very rapidly to 1-bromo-isopropyl radical. In view of this the observed exclusive terminal addition of Br atoms in the case of propylene could be in part due to rapid rearrangement. 

Alkene Used ethylene propylene 1-butene 1-pentene 1-octene... 

Cationic [ZrBz3]+ species are capable of polymerising oc-olefins such as propylene, 1-butene and 1-pentene at elevated temperature. It is worth emphasising that the non-metallocene [Zr(CH2Ph)3] + [PhCH2B(C6F5)3] catalyst, which is a cationic arene zirconium complex [189], is capable, at least partially, of isospecific a-olefin polymerisation at relatively high temperature [162,189,190],... 

The different reactivities of the olefins are important for the copolymerisation. The comonomer reactivity ratio, rj, in copolymerisation with ethylene appears to decrease with increasing steric hindrance around the double bond in the a-olefin in to the following order [250] ethylene > propylene > 1-butene > linear a-olefin > branched a-olefin. 

Preferred olefins in the polymerisation are one or more of ethylene, propylene, 1-butene, 2-butene, 1-hexene, 1-octene, 1-pentene, 1-tetradecene, norbornene and cyclopentene, with ethylene, propylene and cyclopentene. Other monomers that may be used with these catalysts (when it is a Pd(II) complex) to form copolymers with olefins and selected cycloolefins are carbon monoxide (CO) and vinyl ketones of the general formula H2C=CHC(0)R. Carbon monoxide forms alternating copolymers with the various olefins and cycloolefins. 

In a subsequent paper (187) the same authors studied the kinetics of propylene/1-butene codimerization over the same NiX/Li20 catalyst. 

For the oxidation of ethylene, propylene, 1-butene, and cia- and froms-2-butene, Henry 286, 287) has shown that the rate expression is... 

Laboratory systems containing hydrocarbons and NOa in air were irradiated and analyzed for oxidants. Four hydrocarbons that produced large amounts of HCHO per mole of reacted hydrocarbon were 1,3,5-trimethylbenzene, propylene, 1-butene, and ethylene. Hydrogen peroxide was detected in all four systems. Ozone was the major oxidant in these systems. Figure 2 shows the fate of a mixture of 5.5 ppm of ethylene (C2H4) and 2.2 ppm of NO2 irradiated at 3660 A for 11 hours. The O3... 

There is hindered rotation about any carbon-carbon double bond, but it gives rise to geometric isomerism only if there is a certain relationship among the groups attached to the doubly-bonded carbons. We can look for this isomerism by drawing the possible structures (or better yet, by constructing them from molecular models), and then seeing if these are indeed isomeric, or actually identical. On this basis we find that propylene, 1-butene, and isobutylene should not show... 

CO, CH4, CO2, acetone, ketene. ethene. propene. 1-butene, benzene, toluene, xylene, cydopentene, methyl ethyl ketone, diethyl ketone, methyl-n-propyl ketone, di-n-propyl ketone, methyl vinyl ketone, methyl Isopropenyl ketone, methyl isopropyl ketone, ethyl vinyl ketone, trace amounts of methyl-n-bulyl ketone, cyclopentanone, cydohexanone. acrolein, ethanal. butanal. chain fragments, some monomer CO. CH4, COj, ketene, 1-butene, propene, acetone, methyl ethyl ketone, methyl n-propyl ketone, 1,4-cyclohexadiene. toluene, l-methy. l.3-cydohexadlene, 2-hexanone, cydopentene, 1-methyl cydopentene. mesityl oxide, xylenes, benzene, ethene, cyclopentanone, 1.3-cyclopentad iene, diethyl ketone, short chain fragments, traces of monomer CO, CH4, COi, ketene, 1-butene, propene, acetone, methyl ethyl ketone, methyl isopropyl ketone, methyl-n-propyl ketone, diethyl ketone, methyl propenyl ketone, 3-hexanone. toluene, 2-hexanone. 1,3-cydopentadiene, cyclopentanone, 2-melhylcydopenlanone, mesityl oxide, xylenes, benzene, propionaldehyde, acrolein, acetaldehyde ethene, short chain fragments, traces of monomer CO, COj, H2O, CH4. acetone, ketene, ethene, propylene, 1-butene, methyl vinyl ketone, benzene, acrylic add, toluene, xylene, short chain fragments such as dimer to octamer with unsaturated and anhydride functionalities... 

PE-LLD and even PE-VLD can further be synthesized with metallocenes and methylalumoxanes in the bulk ethylene (high-pressure) process. The polymerization is performed in a stirred tank reactor at temperatures above 120°C and pressures of at least 50 MPa [65, 66]. The copolymer continuously leaves the reactor with excess ethylene, then the ethylene is vented and recycled into the polymerization reactor. The polymer melt is transferred into pellets. In this case the comonomers are propylene, 1-butene, and 1-hexene. 

Introduction of metallocenes in state-of-the-art technologies gives access to new copolymers of ethylene and 1-olefins such as propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene with narrow molecular mass distributions and uniform copolymer compositions. On this basis it is possible to synthesize polyolefins with well-balanced properties. These metallocene/methylalumoxane... 

K Ethylene Propylene 1- Butene iso- Butene cis-2- Butene trans 2- Butene... 

Figure 20 Glass transition temperature (Tg) for ethylene/a-olefin co-polymers in the range 0 mol%< ethylene <100 mol%.454 504,507 515. O propylene 1-butene <> 1-hexene 1-octene.

The regenerated carbonium ion can of course continue the process, a key feature being that under alkylation conditions this active species is formed from saturated alkane, not an olefin as required by polymerization. Different alkenes, such as propylene, 1-butene, or the 2-butenes may also form carbonium ions in a similar manner to the process of Eq. 18.25. However, neither /7-butane nor /7-pentane can replace an isoalkane for the hydride transfer since an /7-alkane is not capable of forming a stabilized carbonium ion. Nevertheless, this is one advantage that the alkylation process has over polymerization as a route to gasoline it is able to use both light hydrocarbon alkanes (as long as they are branched) and alkenes. Alkylation and polymerization both produce branched products, but the alkylation products are saturated (Table 18.5) whereas the polymerization products are alkenes. 

Chen, S.-J. and Radosz, M., Density-tuned polyolefin phase equihbria. 1. Binary solutions of alternating poly(ethylene-propylene) in subcritical and supercritical propylene, 1-butene and 1-hexene. Experimental and Flory-Patterson model, Macrontolecules, 25, 3089-3096, 1992. 

The data in Table 1 summarize catalytic activities for epoxidation of a variety of olefins over an unpromoted 5%Ag/Al203 catalyst. These data illustrate the preferential reactivity at the allylic position relative to addition of oxygen across the C=C bond. While the selectivity to ethylene oxide is typical for an unpromoted catalyst, the selectivities to propylene oxide and butylene oxides are non-existent for propylene, 1-butene, and 2-butene, respectively. In addition to small amounts of the selective allylic oxidation products (acrolein in the case of propylene and butadiene in the case of 1-butene), the only products are those of combustion. However, the results for butadiene reveal it is possible to epoxidize this non-allylic olefin at moderate selectivity and activity. What is not obvious from Table 1 is the short-lived nature of this activity. After 2-3 hours of reaction time, activity and selectivity typically decreased to approximately <1% conversion of C4H6 and approximately 50-75% selectivity to epoxybutene. A typical chromatogram of the activity of an... 

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