Hydrocarbons, aliphatic unsaturated

Chakactkrisation of Unsaturatkd Aliphatic Hydrocarbons Unlike the saturated hydrocarbons, unsaturated aliphatic hydrocarbons are soluble in concentrated sulphuric acid and exhibit characteristic reactions with dUute potassium permanganate solution and with bromine. Nevertheless, no satisfactory derivatives have yet been developed for these hydrocarbons, and their characterisation must therefore be based upon a determination of their physical properties (boiling point, density and refractive index). The physical properties of a number of selected unsaturated hydrocarbons are collected in Table 111,11. 

Saturated Aliphatic Hydrocarbons, Table III, 6. Unsaturated Aliphatic Hydrocarbons, Table III, 11. Aromatic Hydrocarbons, Table IV, 9. 

Alkadienes, alkatrienes, and alkatetraenes (poly-enes). These are unsaturated aliphatic hydrocarbons containing two, three, or four C = C double bonds, respectively. Alkadienes are also called diolefins or dienes, and alkatrienes are also known as triolefins or tricncs. Alkenes containing multiple double bonds fall under the general class of poly-enes. Double bonds that alternate with single bonds in a straight chain are said to be conjugated. Examples are... 

OLEFINS. Unsaturated aliphatic hydrocarbons with great chemical activity. 

Olefins or alkenes are defined as unsaturated aliphatic hydrocarbons. Ethylene and propylene are the main monomers for polyolefin foams, but dienes such as polyisoprene should also be included. The copolymers of ethylene and propylene (PP) will be included, but not polyvinyl chloride (PVC), which is usually treated as a separate polymer class. The majority of these foams have densities <100 kg m, and their microstructure consists of closed, polygonal cells with thin faces (Figure la). The review will not consider structural foam injection mouldings of PP, which have solid skins and cores of density in the range 400 to 700 kg m, and have distinct production methods and properties (456). The microstructure of these foams consists of isolated gas bubbles, often elongated by the flow of thermoplastic. However, elastomeric and microcellular foams of relative density in the range 0.3 to 0.5, which also have isolated spherical bubbles (Figure lb), will be included. The relative density of a foam is defined as the foam density divided by the polymer density. It is the inverse of the expansion ratio . 

Iodine is reactive toward unsaturated aliphatic hydrocarbons and the iodine number is a well-known measure for the degree of unsaturation of fatty acids [164]. The electroiodination of unsaturated and aromatic hydrocarbons also is well known and can be achieved, for example, by electrogeneration of I" in acetonitrile [165] (Eq. 13). The reaction has been proposed to be consistent with a conventional homogeneous electrophilic aromatic substitution. 

Saturated and unsaturated aliphatic hydrocarbons with straight as well as branched chains occur abundantly in natural foodstuffs, but they contribute to the odor and taste only to a limited extent. The highly unsaturated hydrocarbons l,3-fra y-5-ci5-undecatriene [51447-08-6] and l,3-trany-5-tran -undecatriene [19883-29-5], however, contribute to the odor of galbanum oil [10]. 

Alkylidene. A divalent organic radical derived from an unsaturated aliphatic hydrocarbon eg, ethylidene (Hs C. CH =), poopylidene, (CHjCHjCH") etc Alkylideneperoxide. The name coined by... 

Alkyne ( Acetylene Series). A group of unsaturated aliphatic hydrocarbons of the general formula C, contg triple bonds. 

The nomenclature of the acyclic hydrocarbons can be readily systematized by naming them in the same manner as other unsaturated aliphatic hydrocarbons (7,42). Hydro derivatives as well as methyl or other alkylated derivatives of the acyclics can be named systematically similarly to the hydrocarbons, and the system can be applied readily to derivatives containing functional groups. 

Name the acyclic terpene hydrocarbons in a manner similar to other unsaturated aliphatic hydrocarbons (I UP AC rules) when pure compounds are involved. 

Names of branched-chain unsaturated aliphatic hydrocarbons (IUPAC rules) are formed from the name of the longest fundamental chain present in a formula and the names of the side chains with proper position designations. The resulting names... 

Only an insignificant amount of unsaturated aliphatic hydrocarbons is admissible in toluene for nitration. They may be detected by shaking a sample with concentrated sulphuric acid. If the toluene is pure, the sulphuric acid separates very quickly as a colourless or slightly yellow ( straw yellow ) lower layer. If unsaturated hydrocarbons are present in significant quantities a stable emulsion is often formed, and the sulphuric acid turns brown or even black. Such a product cannot be used for nitration. 

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