Ethylene saturation

For example, a PE-fe-poly(ethylene-co-propylene) diblock composed of crystalline PE and amorphous ethylene/propylene copolymer segments was synthesized from ethylene and ethylene/propylene. The addition of MAO and Ti-FI catalyst 40 (Fig. 25) to an ethylene-saturated toluene at 25 °C resulted in the rapid formation of a living PE (Mn 115,000, MJMn 1.10). The addition of ethylene/propylene (1 3 volume ratio) to this living PE formed a PE-/>poly(ethylcnc-co-propylcnc) block copolymer (Mn 211,000, MJMn 1.16, propylene content 6.4 mol%) [30], As expected, the polymer exhibits a high Tm of 123 °C, indicating that this block copolymer shows good elastic properties at much higher temperatures than the conventional random copolymers of similar densities. 

In 1980, Miller et al. [76] reported the first example of an intermolecular hydroacylation of an aldehyde with an olefin to give a ketone, during their studies of the mechanism of the rhodium-catalyzed intramolecular cyclization of 4-pentenal using ethylene-saturated chloroform as the solvent. Later James and Young [77] reported that the reaction of propionaldehyde with ethylene can be conducted in the presence of RuCl2(PPh3)3 as the catalyst without any solvent at 210 °C, resulting in the formation of 3-pentanone in 2-4% yield (turnover number of 230) (Eq. 49). 

Ethylene may also be polymerised in [C4Ciim]Cl-AlCl3-AlCl2Et (1 1 0.32) in the presence of the nickel(II) bisimine complex, 43, and toluene as co-solvent.1" After the reaction, the upper toluene layer contains the product while the catalyst remains in the ionic liquid. After decantation, the second run was initiated by introducing a new batch of ethylene-saturated... 

Further evidence of the living polymerization nature was obtained by the fact that the GPC peaks of the PE produced shift to higher molecular mass on increasing the polymerization time. The monomodal shape is retained, and no shoulders or low molecular mass tails are detected.1134 The stability of the living polymer chain was investigated utilizing the MAO-activated complex 137 at 25 °C.1134 First, the activated complex is treated with ethylene-saturated toluene for 65 min. The values of Mn versus time clearly indicate that after 3 min all the ethylene is consumed. After 65 min under an N2 atmosphere, ethylene gas was fed to the system for 2 additional min. The Mw/Mn value resulting after the additional 2 min ethylene feed is 1.14, which indicates that no termination reaction occurred for at least 60 min in the absence of ethylene. This remarkable result opens the route to the controlled synthesis of ethylene-based block co-polymers. 

The reaction occurs by initial dissociation of triphenylphosphiine. For isolation of the product the reaction must be carried out in an ethylene-saturated solution under an atmosphere of ethylene. Other olefins generally form too weak a complex with Rh(I) to be able to displace triphenylphosphine. Olefins such as dimethylmaleate and tetracyan-oethylene disfilace triphenylphosphine from Ir(I) ... 

The intramolecular hydroacylation of olefins typically occurs in higher yields than the intermolecular hydroacylation of olefins. In its simplest form, the reaction of 4-pentenone in the presence of stoichiometric amoimts of V 5Udnson s catalyst at room temperature in ethylene-saturated solvent formed the isomeric cyclopentanone in good yield after long reaction times (Equation 18.86). Many different cyclopentanones were prepared by related methods. " ... 

The Pd( 100) and Pd( 111) ethylene saturation coverages at low temperatuie UltV conditions. 

Poly(ethylene-co-vinyl acetate) Ambient to 500 Acetic add, ketene, CO2, ethylene, saturated and usaturated 92... 

The solid appears to be a mixture of the complexes CH,COOH.BF, and 2CH COOH.BF,. The latter appears to be a liquid and is alone soluble in ethylene dichloride the former is a solid. The solid moiioocetic acid complex is obtained by saturating an ethylene dichloride solution of acetic acid with boron trifluoride, filtering and washing the precipitate with the solvent it is hygroscopic and should be protected from moisture. It may be used as required 0-75 mol is employed with 0-26 mol of ketone and 0 6 mol of anhydride. 

Prepare a saturated solution of sodium sulphide, preferably from the fused technical sodium polysulphide, and saturate it with sulphur the sulphur content should approximate to that of sodium tetrasulphide. To 50 ml. of the saturated sodium tetrasulphide solution contained in a 500 ml. round-bottomed flask provided with a reflux condenser, add 12 -5 ml. of ethylene dichloride, followed by 1 g. of magnesium oxide to act as catalyst. Heat the mixture until the ethylene dichloride commences to reflux and remove the flame. An exothermic reaction sets in and small particles of Thiokol are formed at the interface between the tetrasulphide solution and the ethylene chloride these float to the surface, agglomerate, and then sink to the bottom of the flask. Decant the hquid, and wash the sohd several times with water. Remove the Thiokol with forceps or tongs and test its rubber-like properties (stretching, etc.). 

A solution of a-lithiomethoxyallene was prepared from nethoxyal lene and 0.20 mol of ethyllithiurn (note 1) in about 200 ml of diethyl ether (see Chapter II, Exp. 15). The solution was cooled to -50°C and 0.20 mol of ethylene oxide was added immediately. The cooling bath was removed temporarily and the temperature was allowed to rise to -15 c and was kept at this level for 2.5 h. The mixture was then poured into 200 ml of saturated ammonium chloride solution, to which a few millilitres of aqueous ammonia had been added (note 2). After shaking the layers were separated. The aqueous layer was extracted six times with small portions of diethyl ether. The combined ethereal solutions were dried over sodium sulfate and subsequently concentrated in a water-pump vacuum. Distillation of the... 

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). 

Chlorine reacts with saturated hydrocarbons either by substitution or by addition to form chlorinated hydrocarbons and HCl. Thus methanol or methane is chlorinated to produce CH Cl, which can be further chlorinated to form methylene chloride, chloroform, and carbon tetrachloride. Reaction of CI2 with unsaturated hydrocarbons results in the destmction of the double or triple bond. This is a very important reaction during the production of ethylene dichloride, which is an intermediate in the manufacture of vinyl chloride ... 

Aliphatic Chemicals. The primary aliphatic hydrocarbons used in chemical manufacture are ethylene (qv), propjiene (qv), butadiene (qv), acetylene, and / -paraffins (see Hydrocarbons, acetylene). In order to be useflil as an intermediate, a hydrocarbon must have some reactivity. In practice, this means that those paraffins lighter than hexane have Httle use as intermediates. Table 5 gives 1991 production and sales from petroleum and natural gas. Information on uses of the C —C saturated hydrocarbons are available in the Hterature (see Hydrocarbons, C —C ). 

Irradiation of ethyleneimine (341,342) with light of short wavelength ia the gas phase has been carried out direcdy and with sensitization (343—349). Photolysis products found were hydrogen, nitrogen, ethylene, ammonium, saturated hydrocarbons (methane, ethane, propane, / -butane), and the dimer of the ethyleneimino radical. The nature and the amount of the reaction products is highly dependent on the conditions used. For example, the photoproducts identified ia a fast flow photoreactor iacluded hydrocyanic acid and acetonitrile (345), ia addition to those found ia a steady state system. The reaction of hydrogen radicals with ethyleneimine results ia the formation of hydrocyanic acid ia addition to methane (350). Important processes ia the photolysis of ethyleneimine are nitrene extmsion and homolysis of the N—H bond, as suggested and simulated by ab initio SCF calculations (351). The occurrence of ethyleneimine as an iatermediate ia the photolytic formation of hydrocyanic acid from acetylene and ammonia ia the atmosphere of the planet Jupiter has been postulated (352), but is disputed (353). 

Phthahc anhydride (1) is the commercial form of phthaUc acid (2). The worldwide production capacity for the anhydride was ca 3.5 x 10 metric tons ia 1993, and it was used ia the manufacture of plasticizers (qv), unsaturated polyesters, and alkyd resins (qv) (see Polyesters, unsaturated). Sales of terephthahc acid (3) and its dimethyl ester are by far the largest of any of the benzenepolycarboxyhc acids 14.3 x 10 t were produced in 1993. This is 80% of the total toimage of ah. commercial forms of the benzenepolycarboxyhc acids. Terephthahc acid is used almost exclusively for the manufacture of poly(ethylene terephthalate), which then is formed into textiles, films, containers, and molded articles. Isophthahc acid (4) and trimehitic anhydride (5) are commercial products, but their worldwide production capacities are an order of magnitude smaller than for terephthahc acid and its dimethyl ester. Isophthahc acid is used primarily in the production of unsaturated polyesters and as a comonomer in saturated polyesters. Trimehitic anhydride is used mainly to make esters for high performance poly(vinyl chloride) plasticizers. Trimesic acid (6), pyromehitic dianhydride (7), and hernimehitic acid (8) have specialized commercial apphcations. The rest of the benzenepolycarboxyhc acids are not available commercially. 

Purified terephthalic acid and dimethyl terephthalate are used as raw materials for the production of saturated polyesters. During 1993, the combined worldwide production of purified terephthafic acid plus dimethyl terephthalate exceeded 14 x 10 t (42), which is 80% of the total benzenepolycarboxyfic acid production. Terephthafic acid is also produced ia technical or cmde grades which are not pure enough for manufacture of poly(ethylene terephthalate). In almost all cases, the technical-grade material is immediately converted to purified terephthafic acid or dimethyl terephthalate, which together are the articles of commerce. 

Most elastomers that are used for nylon modification contain a small amount of maleic anhydride (0.3 to 2%). In the melt blending process, these elastomers react with the primary amine end groups in nylon, giving rise to nylon grafted elastomers. These grafts reduce the interfacial tension between the phases and provide steric stabili2ation for the dispersed mbber phase. Typically, thermally stable, saturated mbbers such as EPR, EPDM, and styrene—ethylene/butylene—styrene (SEBS) are used. 

The process yields a random, completely soluble polymer that shows no evidence of crystallinity of the polyethylene type down to —60°C. The polymer backbone is fully saturated, making it highly resistant to ozone attack even in the absence of antiozonant additives. The fluid resistance and low temperature properties of ethylene—acryUc elastomers are largely a function of the methyl acrylate to ethylene ratio. At higher methyl acrylate levels, the increased polarity augments resistance to hydrocarbon oils. However, the decreased chain mobiUty associated with this change results in less fiexibihty at low temperatures. 

---