Paraffins chemical properties

The physical and chemical properties of chlorinated paraffins are deteanined by the carbon chain length of the paraffin and the chlorine content. This is most readily seen with respect to viscosity (Fig. 1) and volatiUty (Fig. 2) increasing carbon chain length and increasing chlorine content lead to an increase in viscosity but a reduction in volatiUty. 

Paraffins are relatively inactive compared to olefins, diolefins, and aromatics. Few chemicals could be obtained from the direct reaction of paraffins with other reagents. However, these compounds are the precursors for olefins through cracking processes. The C -Cg paraffins and cycloparaffms are especially important for the production of aromatics through reforming. This section reviews some of the physical and chemical properties of C1-C4 paraffins. Long-chain paraffins normally present as mixtures with other hydrocarbon types in different petroleum fractions are discussed later in this chapter. 

Like propane, butanes are obtained from natural gas liquids and from refinery gas streams. The C4 acyclic paraffin consists of two isomers n-butane and isobutane (2-methylpropane). The physical as well as the chemical properties of the two isomers are quite different due to structural differences, for example, the vapor pressure (Reid method) for n-butane is 52 Ib/in., while it is 71 Ib/in. for isobutane. This makes the former a more favorable gasoline additive to adjust its vapor pressure. However, this use is declining in the United States due to new regulations that reduce the volatility of gasolines to 9 psi, primarily by removing butane. ... 

It may also be represented as a hexagon with a circle in the middle. The circle is a symbol of the n cloud encircling the benzene ring. The delocalized electrons associated with the benzene ring impart very special properties to aromatic hydrocarbons. They have chemical properties of single-bond compounds such as paraffin hydrocarbons and doublebond compounds such as olefins, as well as many properties of their own. 

It has been shown (9) that asphaltenes contain a broad distribution of polarities and molecular weights. According to these studies, the concept of asphaltenes is based on the solubility behavior of high-boiling hydrocarbonaceous materials in benzene and low-molecular weight n-paraffin hydrocarbons. This solubility behavior is a result of physical effects that are caused by a spectrum of chemical properties. Long also... 

The red and orange forms of RhCl[P(C6H5)3]3 have apparently identical chemical properties the difference is presumably due to different crystalline forms, and possibly bonding in the solid. The complex is soluble in chloroform and methylene chloride (dichloromethane) to about 20 g./l. at 25°. The solubility in benzene or toluene is about 2 g./l. at 25° but is very much lower in acetic acid, acetone, and other ketones, methanol, and lower aliphatic alcohols. In paraffins and cyclohexane, the complex is virtually insoluble. Donor solvents such as pyridine, dimethyl sulfoxide, or acetonitrile dissolve the complex with reaction, initially to give complexes of the type RhCl[P(C6H6)3]2L, but further reaction with displacement of phosphine may occur. 

The implications of these deductions seem to lead to the conclusion that such structural factors as chain length, methyl groups, and double bonds influence not only the physical properties but the chemical properties of the hydrocarbon as well. Hydrocarbons are limited in their chemical reactivity. The paraffins are compounds having small affinity. The hydrocarbon molecules are armor-plated with hydrogen. Since structure plays so vital a role in the rate of combustion, there must be a fundamental difference in the relative reactivity of the hydrogen atoms. Experimental evidence that such is the case is accumulating. There are reasons to believe that methods are at hand by which the... 

Feolite catalysts modified by transition metals are interesting and difficult subjects to study. In one of the first studies of zeolites as catalysts, Rabo and co-workers (1) used a zeolite catalyst containing 0.5% platinum for isomerization of n-paraffins. In this reaction the metal-zeolite system acted as a typical representative of the bifunctional catalysts. Studies of zeolites modified by transition metals ( 2, 3, Jf) showed that their polyfunctional properties are determined by the structural and chemical properties of the zeolite and by the state of the metal in it. In this paper we discuss new data on the metal state after reduction as well as the catalytic functions of zeolite catalysts containing nickel and platinum. 

The rubbery character and particular physical and chemical properties of polyisobutene stem from its paraffinic origins. Its outstanding properties are its low glass transition temperature, very low water vapor permeability and resistance to many chemicals. At room temperature polyisobutene is resistant to dilute and concentrated mineral acids and bases, as well as hydrogen peroxide. 

The continuous phase in the ABS polymer is responsible for most of its chemical properties. Because of the presence of only C-C binding in the polymer chain no hydrolytic reactions can take place. ABS polymers are in general resistant to aqueous salt, base or acid solutions and are not dissolved by paraffinic hydrocarbons. Depend-... 

Tatevskii VM, Benderskii VA and Yarovoi SS, "Rules and Methods for Calculating the Physico-chemical Properties of Paraffinic Hydrocarbons", Pergamon Press, London, 1961. 

Even after a very short experience, it was evident that corresponding derivatives of the two elements in question showed very considerable differences in their chemical properties it may now be said that the principal if not the only case in which they exhibit a really close resemblance is that of the paraffins and those particular silicohydrocarbons, containing a silicon atom directly united to four alkyl radicals.2... 

Values for the index between 0 and 15 indicate a predominance of paraffinic hydrocarbons in the fraction. A value from 15 to 50 indicates predominance of either naphthenes or mixtures of paraffins, naphthenes, and aromatics. An index value above 50 indicates a predominance of aromatic species. However, it cannot be forgotten that the data used to determine the correlation index are average for the fraction of feedstock under study and may not truly represent all constituents of the feedstock, especially those at both ends of a range of physical and chemical properties. 

Hydrocarbons — Organic chemical compounds composed only of the elements carbon and hydrogen. Hydrocarbons are the principal constituents of crude oils, natural gas, and refined petroleum products and include four major classes of compounds (alkanes, alkenes, naphthenes, and aromatics) each with characteristic structural arrangements of hydrogen and carbon atoms, as well as different physical and chemical properties. (See also Alkanes, Alkenes, Aromatics, Naphthenes, Olefins, Paraffin, Saturate group.)... 

Physical and Chemical Properties. Petrol, diesel and paraffin vapors are heavier than air and as a result of this may be encountered in fuel tanks, in vehicles or in spaces where fuels have been... 

It is a relatively recent observation that Colchicum species contain numerous chemical constituents of diverse chemical properties. Recognition of this fact has led to more efficient methods of isolation. In addition to neutral, phenolic, and basic alkaloids, 0. autumnale contains fatlike substances which are removed by a preliminary ligroin extraction of the pulverized, dry material. From such an extraction of the flowers of C. autumnale, Santavy and Herout (293) have isolated a paraffin, Ca7-28H5g 58, m.p. 58-60° an alcohol, CaaH450H, m.p. 66-67° and a phytosterol, m.p. 139-140°. Benzoic, salicylic, and 2-hydroxy-6-methoxybenzoic acids may be separated from the alkaloid mixture by virtue of their solubility in ether and aqueous base (294). The alkaloids themselves may be separated into neutral, phenolic, or basic fractions by standard extraction techniques. Pure alkaloids may be obtained from each fraction by fractional crystallization and chromatography on... 

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