Ethylene molar concentrations

Within the scope of the original definition, a very wide variety of ionomers can be obtained by the introduction of acidic groups at molar concentrations below 10% into the important addition polymer families, followed by partial neutralization with metal cations or amines. Extensive studies have been reported, and useful reviews of the polymers have appeared (3—8). Despite the broad scope of the field and the unusual property combinations obtainable, commercial exploitation has been confined mainly to the original family based on ethylene copolymers. The reasons for this situation have been discussed (9). Within certain industries, such as flexible packaging, the word ionomer is understood to mean a copolymer of ethylene with methacrylic or acryhc acid, partly neutralized with sodium or zinc. 

Flame Studies. The effects of ethylene dibromide, bromoform, and chloroform on flame speeds of several hydrocarbons were examined. These studies were carried out with 5% molar concentration of the halogen compounds in each hydrocarbon. All the experiments were carried out under identical conditions, and the results reported in Table I are the mean of at least three separate determinations. 

Inspired by the formulation of Eq. (c7), numerous experiments have been performed. Assuming the approximate equality, Kx =[EX] (molar concentration of x-rings), Jones and coworkers [100] measured the Kx values up to x = 7 in ring-chain equilibria of linear aliphatic polyesters. In Table 2 are summarized their results for Zx(px and Zxaromatic polyester[ 101-102], and poly(ethylene terephthalate) for reference. 

Figure 3.9 shows the cmc as a function of molar composition of the solution and in the micelles for a mixture of SDS and nonylphenol with 10 mol ethylene oxide (NP-Ejq). If the molar composition of the micelles is used as the x-axis, the cmc is more or less the arithmetic mean of the cmcs of the two surfactants. If, on the other hand, the molar composition in the solution is used as the x-axis (which at the cmc is equal to the total molar concentration), then the cmc of the mixture... 

The reaction between a mole each of benzyl cyanide and ethylene diamine in the presence of carbon disulphide as a medium gives rise to the formation of the desired tolazoline (base) through cyclization and subsequent elimination of a mole each of hydrogen sulphide and ammonia that are liberated from the reaction mixture. The base thus obtained is treated with a HCl in molar concentration to obtain the corresponding salt. 

Figure 19.5. The logarithm of the CMC (molar concentration) versus the number of carbons in the alkyl chain for various octa(ethylene glycol)monoalkyl ethers at different temperatures. From top to bottom, the temperatures are 15.0, 20.0, 25.0, 30.0 and 40.0°C. (Redrawn from K. Meguro, M. Ueno and K. Esumi, in Nonionic Surfactants Physical Chemistry, M. J. Schick (Ed.), Marcel Dekker, New York, 1987, p. 134)...

The molar concentrations of phenol and ethylene in this system, however, decrease almost equally rapidly. The rate of consumption of phenol is practically independent of the ethylene oxide concentration for molar ratios of ethylene oxide/phenol of <1 1, but this rate is dependent on the concentration of sodium phenolate or phenol, itself. 

Figure 23-1. Acceleration of the bromoacetate-thiosulfate reaction at 25 C by various low-molar-mass and high-molar-mass electrolytes as a function of the molar concentration (El) with respect to catalytically effective groups. PEI nHCl, Poly (ethylene imine hydrochloride) TP 5HC . tetraethylene pentamine hydrochloride DT-3HC1, diethylene triamine hydrochloride. The bromoacetate and thiosulfate concentrations were, in each case, 0.01 mol liter unless otherwise noted. (After N. Ise and F. Matsui.)...

More exact study has shown, however, that ethylene oxide does not react with either phenol or sodium phenate alone. In the ethylene oxide/phenol/ sodium phenolate system, the amounts (in moles) of phenol and ethylene oxide decrease almost the same with time. The decrease in phenol is practically independent of the ethylene oxide concentration, until a molar ratio of ethylene oxide/phenol of 1 1 is reached. It does depend, however, on both the concentration of sodium phenolate and that of the phenol itself... 

The chain-growth catalyst is prepared by dissolving two moles of nickel chloride per mole of bidentate ligand (BDL) (diphenylphosphinobenzoic acid in 1,4-butanediol). The mixture is pressurized with ethylene to 8.8 MPa (87 atm) at 40°C. Boron hydride, probably in the form of sodium borohydride, is added at a molar ratio of two borohydrides per one atom of nickel. The nickel concentration is 0.001—0.005%. The 1,4-butanediol is used to solvent-extract the nickel catalyst after the reaction. 

Tlie first suggestion of a template effect which was offered in the literature was made by Greene in 1972 °. Tlie illustration of this concept is approximately that shown in Eq. (2.2), above. Greene presented several pieces of evidence in addition to the concept itself. First, he noted that when the final concentration of 18-crown-6 in a reaction mixture (MejSO) was increased from 0.04 At to 0.09 Af, the yield of crown dropped only slightly (84% to 75%). In a competition experiment, equal amounts of 18-crown-6 and 21-crown-7 were formed when one molar equivalent each of triethylene glycol and tetra-ethylene glycol were allowed to compete for triethylene glycol ditosylate (KO-t-Bu/THF). 

Fig. 12 The evolution of the aggregate with polymer concentration or the molar ratio of NIPAM to ethylene oxide (EO) above the LCST [170]...

As described in Section 3.2.3, the use of acidic supports such as A1203 favors the dehydration of ethanol to ethylene, which leads to a severe carbon deposition.66,76,78,85 Reactions with lower H20/ethanol ratio can also favor several side reactions mentioned above and result in carbon deposition on the catalyst surface. Possible strategies to reduce the carbon deposition include (i) neutralization of acidic sites responsible for ethanol dehydration to ethylene and/or modification of the support nature, including less acidic oxides or redox oxides, (ii) use of a feed containing higher H20/ethanol molar ratio, and (iii) addition of a small concentration of air or 02 in the feed. 

The Au-catalyzed glycerol oxidation was influenced by the kind of support, the size of Au particles and the reaction conditions such as concentration of glycerol, p02 and molar ratio of NaOH to glycerol. As metal oxide supports showed inferior selectivity to glyceric acid compared to carbons, due to successive oxidation and C—C bond cleavage to form di-adds such as tartronic acid and glycolic acid, research has focused on Au NPs supported on carbon, as in the case of ethylene glycol oxidation [182]. Indeed, the catalytic activity was influenced by the kind of carbon support in terms of porous texture [183]. 

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