Carbon vinylacetate

A series of tests [15] were conducted to compare three types of polymeric modifiers for PVC Du Ponf s Elva-loy 741, a copolymer of ethylene, vinylacetate, and carbon monoxide Goodyear s Chemigum P83, a copolymer of butadiene and acrylonitrile and 566TPU from our lab, a polyester-based TPU. Some of the results are provided in Tables 5 and 6. 

Vinyl acetate, 57,117 Vinylacetic acid, 56,49 ct-Vinylbenzyl alcohol, 56, 106 Vinyl bromide, 58,152, 155, 157 Vinyl chloride, 58,133 Vinylene carbonate, 57, 117 Vinylmagnesium halides, 59,92 2-Vinylpytidine, 58, 73 Vinyl sulfides, 59, 202... 

The only practical methods for the preparation of vinylacet.ic acid involve hydrolysis of allyl cyanide 6 carbonation of allylmag-nesium bromide 8 or the malonic acid synthesis.9... 

Robeson LM, Kuphal JA (1989) Blends of poly(vinylacetate) and poly(propylene carbonate). US Patent 4,912,149... 

The regiospecificity of the cycloadditions is the same as the regiospecificity of the additions to 50, 65, and 74 with respect to the carbonyl but opposite with respect to the nitrogen of the carbon-nitrogen double bond. The vinylacetate cycloadduct of 6-azauracil has been shown to be as useful intermediate for the synthesis of 5-substituted uracils70. ... 

Internal plasticizers are synthesized by copolymerization of suitable monomers. Polymeric non-extractable plasticizers, mostly copolymers having substantially lower glass transition temperatures due to the presence of plasticizing ( soft ) segments such as poly(ethylene-co-vinyl acetate) with approximately 45 % vinylacetate content, ethylene-vinyl acetate-carbon monooxide terpolymer, or chlorinated PE, are available for rather special applications in medicinal articles (Meier, 1990). In this case, the performance of the internally plasticized polymers is the principal advantage. However, copolymerization may account for worse mechanical properties. A combination with external plasticizers may provide an optimal balance of properties. For example, food contact products made from poly(vinylidene chloride) should have at most a citrate or sebacate ester based plasticizers content of 5 % and at most 10 % polymeric plasticizers. 

The pronounced amplitude dependence of the complex modulus, referred to as the Payne effect, has also been observed in low viscosity media, e.g., composites of carbon black with decane and liquid paraffin [50], carbon black suspensions in ethylene vinylacetate copolymers [51], and clay/water suspensions [52, 53]. It was found that the storage modulus decreases with... 

Even dynamic measurements have been made on mixtures of carbon black with decane and liquid paraffin [22], carbon black suspensions in ethylene vinylacetate copolymers [23], or on clay/water systems [24,25]. The corresponding results show that the storage modulus decreases with dynamic amplitude in a manner similar to that of conventional rubber (e.g., NR/carbon blacks). This demonstrates the existence and properties of physical carbon black structures in the absence of rubber. Further, these results indicate that structure effects of the filler determine the Payne-effect primarily. The elastomer seems to act merely as a dispersing medium that influences the magnitude of agglomeration and distribution of filler, but does not have visible influence on the overall characteristics of three-dimensional filler networks or filler clusters, respectively. The elastomer matrix allows the filler structure to reform after breakdown with increasing strain amplitude. 

Fig. 8.16 Conductivity of a composite formed from carbon-black coated poly(vinylacetate) pellets (Grunlan et al., 2001). Reprinted by permission of John Wiley Sons, Inc.

Primary steam reforming Secondary steam reforming Carbon monoxide conversion Carbon monoxide methanation Ammonia synthesis Sulfuric acid synthesis Methanol synthesis Oxo synthesis Ethylene oxide Ethylene dichloride Vinylacetate Butadiene Maleic anhydride Phthalic anhydride Cyclohexane Styrene Hydrodealkylation Catalytic reforming Isomerization Polymerization (Hydro)desulfurization Hydrocracking... 

Volatile product evolution has been observed in the photolysis of many vinyl polymers as a consequence of side-group scission. The nature of these volatile products is therefore related to the side group. Carbon dioxide, carbon monoxide and methyl formate are produced from polymethylmethacrylate [12], carbon dioxide, carbon monoxide, methane and acetic acid in the photolysis of poly vinylacetate [13], and hydrogen chloride in the photolysis of polyvinylchloride [14]. 

This approach has been applied [295,298-301] to the reactivity of a large series of carbon-centered radicals (including the benzoyl, hydroxyl alkyl, and aminoalkyl radicals) toward various monomer units (acrylate, methacrylate, vinylether, vinylacetate, etc.). Calculating a and A/i X) yields Zsenth. Linear relationships between Zsenth and A//, are generally found (Equation 10.78). 

E-BA-CO E-VAc-CO (Ethylene-n-butylacrylate-carbon monoxide ethylene-vinylacetate-carbon monoxide)... 

Several studies concentrate on immobilizing catalytic metal particles in polymeric films. Kao and Kuwana prepared films of poly(vinylacetic acid) on glassy carbon electrodes by refluxing them in neat monomer solutions. Electrodeposition of Pt spherical particles in these films resulted in electrocatalytic electrodes for O2 reduction and H2 generation. Electrodeposited Pt in conducting polyaniline films yield extremely stable layers that are electrocatalytic toward methanol oxida-... 

The first PVC/COPO blends were developed in 1960 (Mullins 1964). It was reported that PVC melt viscosity decreased by addition of COPO (Hammer 1973). Later, the compositions were modified - PVC was blended with ethylene-carbon monoxide-vinylacetate copolymer (COPO-VAc) and BMMM (Reardon 1982). 

COPO-VAc Carbon monoxide-ethylene-vinylacetate copolymer... 

Whatever the nature of the elastomer used as matrix, i.e. polyurethane, poly(ethylene-vinylacetate) or styrene-butadiene rubber (SBR), it appears that the interfacial shear strength x of carbon fibre-elastomer composites is much higher than theoretically expected from equation (10). Figure 6 illustrates the variation of x versus W2 in comparison with the prediction from our model in the case of carbon fibre-SBR systems. Any other theoretical approach is able to explain these high values of x. 

The determination of melting points from retention diagrams of homo-polymers has involved the use of different injected substances on poly-(ethylene terephthalate) as granules [174, 175] and fibres [176, 177], 66 nylon fibres [178], polyester fibres [179], poly(ethylene terephthalate) and poly- -caprolactam [180, 181], poly(ethylene oxide) [182,183]. Such diagrams are also known for copolymers such as ethylene-vinylacetate, ethylene-carbon oxide [184] and ethylene oxide-propylene oxide [182]. 

The process is carried out in the gas phase at a temperatures above 160°C. The reaction is exothermic, so heat control in the production process is important. Vinylacetate is used as intermediate in a large number of production processes. The catalysts can be produced by impregnation of an activated carbon with zinc acetate, followed by drying. The zinc concentration is in the order of 11 up to 13%. The optimal activated carbon support is a high steam activated and acid washed 3 or 4 mm extrudate like the NORIT RX 3 EXTRA or NORIT RX 4 EXTRA. Important characteristics of the impregnated carbon are ... 

There remains one more isomerization to be discussed. The formyl group formed in the hydroformylation of olefins with longer carbon chains need not necessarily be attached to one of the C-atoms having previously formed the double bond but can also be bound to other C-atoms of the carbon chain. This is especially the case if the addition to neither C-atom of the double bond results in the formation of an energetically and steri-cally favored alkylcobaltcarbonyl. As an example internal straight chain olefins may be taken. Under favorable reaction conditions they yield nearly the same isomer distribution as the corresponding terminal olefins do [25]. Another example is ethyl vinylacetate which yields the same reaction products as ethyl crotonate does. 

Allyl vinylacetate is the main product in the reaction of allyl alcohol with carbon monoxide in the presence of tris-(tri-(p-fluorophenyl)-phosphine)-platinum at 200 °C without addition of another alcohol. At a reaction temperature of 250 °C allyl crotonate is obtained by thermal isomerization [551],... 

The intermolecular carbon-carbon bond forming reaction involving allylic sulfones has also been considered without mediators. The successful addition of 2-functionalized allyl sulfones to vinylacetate, taking advantage of favorable polar effects, has been performed by Whitham and co-workers (equation (70))... 

In cyclophorase-mitochondrial preparations of kidney, propionate is formed from the terminal 3 carbons of straight-chain fatty acids of the odd series. Crotonic, vinylacetic, and a series of 8-keto acids, all of which are perhaps intermediates of j8-oxidation, are completely oxidized. The oxidase apparently does not distinguish between ct and trans forms of A -unsaturated fatty acids or between the n- and L-forms of j8-hydroxy-acids. The manner in which fatty acids are activated in order to initiate their oxidation is discussed in a later section (VII). 

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