Ethylene data

Fig. 4. Vapor-phase solubility of naphthalene in ethylene. Data points from G. A. M. Diepen and F. E. C. Scheffer, J. Am. Chem. Soc. 70, 4085 (1948) vapor-phase fugacities from (---) Redlich-Kwong equation (-) Ideal gas law.

The separation of formal charges in a polar limiting structure like 2b creates a dipole moment of ca. 20 D. Therefore, if such structures were of great importance, quite high dipole moments should be expected for push-pull ethylenes. Data for a reasonable number of mostly symmetrical and rather rigid compounds are known (Table 20). Several high dipole moments are observed, though not in the vicinity of those required for a complete transfer of the double-bond it... 

Figure 6.6 U.S. production histories for ethylene. (Data courtesy of CMAI.)...

Figure 1.7 Solubility behavior of solid naphthalene in supercritical ethylene (data of Tsekhanskaya, lom-tev, and Mushkina, 1962 and Diepen and Scheffer, 1948b).

Multiple sets of Burnett data were obtained for each isotherm—three sets for ethylene and two sets for helium. Each set consisted of data from a series of four consecutive expansions from the highest to the lowest pressure compatible with our optimum accuracy and precision. The initial pressure for each set was selected so as to intersperse the data from all of the sets over the entire pressure range of interest, 0.3 MPa to 3.7 MPa. Consistent with the extent of the nonideal behavior of the gas, the density-series generalized equation was applied to the ethylene data and the pressure-series generalized equation was applied to the helium data. The parameters in the resulting overdetermined sets of equations then were evaluated using the least-squares constraint. 

The highest power of the series terms chosen to define each isotherm reflected the extent of the nonideality. For the ethylene isotherms, a cubic series was used for temperatures from 0° to 25°C and a quadratic series was used for temperatures from 75° to 175°C. At 50°C, a quadratic series as well as a cubic series were used. For the helium isotherms, a quadratic series was used with the virial coefficient of the quadratic term treated as a constant obtained from published values rather than as a parameter. The other parameters were evaluated more accurately with the quadratic coefficient treated as a constant rather than as a parameter since the contribution of this term was so small for our range of pressures. The term functioned only as a virial remainder. In the helium data analyses, the parameters were common to all of the data. For the ethylene data analyses, only the virial coefficient parameters were common to all of the data an initial density parameter was required for each sequence... 

The results in Table 2 show the copolymerization behavior of Tia and Tim with ethylene. Data from control experiments are also shown in Table 2. Yields of the copolymerizations are reported as percentages relative to the appropriate control. These... 

FIGURE 8.7 Segment volume v determined with monomer molecular mass as a function of copolymer composition data for EVOH and E VAc in dependence on mole fraction of ethylene. Data for SAN are plotted versus mole fraction of acrylonitrile. 

FIGURE 8.11 Internal pressure APfi versus copolymer composition for EVOH and SAN at 220°C and EVAc at 160°C and P = 0 data for EVOH and EVAc are plotted versus mole fraction of ethylene, data for SAN versus mole fraction of styrene. 

FIGURE 10 Glass transition temperature from change of thermal expansion coefficient in isobaric V-T diagram for random copolymer poly(ethylene-co-vinyl alcohol) with 44 mol% of ethylene, data after Funke et al. (2007). 

FIGURE 5.7 Tubular reactor for high-pressure, free-radical polymerization of ethylene. (Data from Doak, K. W., Enc. Polym. Sci. Tech., 6, 386, 1986.)... 

FIGURE 5.10 Gas-phase polymerization of ethylene. (Data from Chem. Eng., 86, 83, Decembers, 1979.)... 

Figure Bl.22.10. Carbon K-edge near-edge x-ray absorption (NEXAFS) speetra as a fiinotion of photon ineidenee angle from a submonolayer of vinyl moieties adsorbed on Ni(lOO) (prepared by dosing 0.2 1 of ethylene on that surfaee at 180 K). Several eleetronie transitions are identified in these speetra, to both the pi (284 and 286 eV) and the sigma (>292 eV) imoeeupied levels of the moleeule. The relative variations in the intensities of those peaks with ineidenee angle ean be easily eonverted into adsorption geometry data the vinyl plane was found in this ease to be at a tilt angle of about 65° from the surfaee [71], Similar geometrieal detenninations using NEXAFS have been earried out for a number of simple adsorbate systems over the past few deeades.

The tipper triangular part of the Huckel matrix for ethylene, Fq, (6-48), exclusive of the diagonal elements consists of only one element. It can be entered into Program QMOBAS by making the dimension of the matrix 2 and changing the data statement to enter 1 in the 1.2 position... 

The activation energy for ro tation about a typical carbon-carbon double bond IS very high—on the order of 250 kj/mol (about 60 kcal/ mol) This quantity may be taken as a measure of the ir bond contribution to the to tal C=C bond strength of 605 kJ/mol (144 5 kcal/mol) in ethylene and compares closely with the value esti mated by manipulation of thermochemical data on page 191... 

The notion that carbocation formation is rate determining follows from our previous experience and by observing how the reaction rate is affected by the shucture of the aUcene Table 6 2 gives some data showing that alkenes that yield relatively stable carbocations react faster than those that yield less stable carbocations Protonation of ethylene the least reactive aUcene m the table yields a primary carbocation protonation of 2 methylpropene the most reactive m the table yields a tertiary carbocation As we have seen on other occa sions the more stable the carbocation the faster is its rate of formation... 

Some data on copolymers of ethylene and propylene (not shown) is also consistent inasmuch as the values of f decrease as the ethylene (unsubstituted) content increases. 

Many simple systems that could be expected to form ideal Hquid mixtures are reasonably predicted by extending pure-species adsorption equiUbrium data to a multicomponent equation. The potential theory has been extended to binary mixtures of several hydrocarbons on activated carbon by assuming an ideal mixture (99) and to hydrocarbons on activated carbon and carbon molecular sieves, and to O2 and N2 on 5A and lOX zeoHtes (100). Mixture isotherms predicted by lAST agree with experimental data for methane + ethane and for ethylene + CO2 on activated carbon, and for CO + O2 and for propane + propylene on siUca gel (36). A statistical thermodynamic model has been successfully appHed to equiUbrium isotherms of several nonpolar species on 5A zeoHte, to predict multicomponent sorption equiUbria from the Henry constants for the pure components (26). A set of equations that incorporate surface heterogeneity into the lAST model provides a means for predicting multicomponent equiUbria, but the agreement is only good up to 50% surface saturation (9). 

Some representative backbone stmctures of PQs and PPQs and their T data are given in Table 1. As in other amorphous polymers, the Ts of PQs and PPQs are controlled essentially by the chemical stmcture, molecular weight, and thermal history. Several synthetic routes have been investigated to increase the T and also to improve the processibiUty of PPQ (71). Some properties of PPQ based on 2,3-di(3,4-diaminophenyl)quinoxaline and those of l,l-dichloro-2,2-bis(3,4-diaminophenyl)ethylene are summarized in Table 2. 

The economics of the arc-coal process is sensitive to the electric power consumed to produce a kilogram of acetylene. Early plant economic assessments indicated that the arc power consumption (SER = kwh/kgC2H2) must be below 13.2. The coal feedcoal quench experiments yielded a 9.0 SER with data that indicated a further reduction to below 6.0 with certain process improvements. In the propane quench experiment, ethylene as well as acetylene is produced. The combined process SER was 6.2 with a C2H2/C2H4 production ratio of 3 to 2. Economic analysis was completed uti1i2ing the achieved acetylene yields, and an acetylene price approximately 35% lower than the price of ethylene was projected. 

Hydrogen Chloride-Organic Compound Systems. The solubihty of hydrogen chloride in many solvents follows Henry s law. Notable exceptions are HCl in polyhydroxy compounds such as ethylene glycol (see Glycols), which have characteristics similar to those of water. Solubility data of hydrogen chloride in various organic solvents are Hsted in Table 10. 

Cyclic Polyolefins (GPO) and Gycloolefin Copolymers (GOG). Japanese and European companies are developing amorphous cycHc polyolefins as substrate materials for optical data storage (213—217). The materials are based on dicyclopentadiene and/or tetracyclododecene (10), where R = H, alkyl, or COOCH. Products are formed by Ziegler-Natta polymerization with addition of ethylene or propylene (11) or so-called metathesis polymerization and hydrogenation (12), (101,216). These products may stiU contain about 10% of the dicycHc stmcture (216). 

Other Polymers. Besides polycarbonates, poly(methyl methacrylate)s, cycfic polyolefins, and uv-curable cross-linked polymers, a host of other polymers have been examined for their suitabiUty as substrate materials for optical data storage, preferably compact disks, in the last years. These polymers have not gained commercial importance polystyrene (PS), poly(vinyl chloride) (PVC), cellulose acetobutyrate (CAB), bis(diallylpolycarbonate) (BDPC), poly(ethylene terephthalate) (PET), styrene—acrylonitrile copolymers (SAN), poly(vinyl acetate) (PVAC), and for substrates with high resistance to heat softening, polysulfones (PSU) and polyimides (PI). 

Similar mechanical data for a series of ionomers derived from a single ethylene—acryflc acid copolymer have appeared (13) (Table 3). Comparison of the data from Tables 2 and 3 shows that the substitution of acryflc acid for methacrylic acid has only minor effects on properties. 

Infrared Spectra of Ionomers. Infrared absorption data, first pubHshed in 1964 (11), show that partial neutralization of ethylene—methacryhc acid introduced new absorption bands at 1480 1670 cm for the ionized carboxylate group while the 1698 — cm band of the free acid carboxyl diminishes in size (21). In addition to providing information on stmctural features, the numerous absorption bands ate significant in apphcations technology, providing rapid warmup of film and sheet under infrared radiation. 

Fig. 2. Glass-transition temperature—molecular weight relationship for poly(ethylene oxide) (-) represents classical T —mol wt relationship Q, data from...

Resonance theory can also account for the stability of the allyl radical. For example, to form an ethylene radical from ethylene requites a bond dissociation energy of 410 kj/mol (98 kcal/mol), whereas the bond dissociation energy to form an allyl radical from propylene requites 368 kj/mol (88 kcal/mol). This difference results entirely from resonance stabilization. The electron spin resonance spectmm of the allyl radical shows three, not four, types of hydrogen signals. The infrared spectmm shows one type, not two, of carbon—carbon bonds. These data imply the existence, at least on the time scale probed, of a symmetric molecule. The two equivalent resonance stmctures for the allyl radical are as follows ... 

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