Linear alkyl

Polymorphism. Many crystalline polyolefins, particularly polymers of a-olefins with linear alkyl groups, can exist in several polymorphic modifications. The type of polymorph depends on crystallisa tion conditions. Isotactic PB can exist in five crystal forms form I (twinned hexagonal), form II (tetragonal), form III (orthorhombic), form P (untwinned hexagonal), and form IP (37—39). The crystal stmctures and thermal parameters of the first three forms are given in Table 3. Form II is formed when a PB resin crystallises from the melt. Over time, it is spontaneously transformed into the thermodynamically stable form I at room temperature, the transition takes about one week to complete. Forms P, IP, and III of PB are rare they can be formed when the polymer crystallises from solution at low temperature or under pressure (38). Syndiotactic PB exists in two crystalline forms, I and II (35). Form I comes into shape during crystallisation from the melt (very slow process) and form II is produced by stretching form-1 crystalline specimens (35). 

The basis of the high normal to isoaldehyde selectivity obtained ia the LP Oxo reaction is thought to be the anti-Markovnikov addition of olefin to HRhCOL2 to give the linear alkyl, Rh(CO)L2CH2CH2CH2CH2, the precursor of straight-chain aldehyde. Anti-Markovnikov addition is preferred ia this... 

Cosurfactant requirements can be minimized usiag a surfactant having a short-branched hydrophobe or a branched-alkyl substituent on an aromatic group (232,234) and a long ethoxy group chain (234). Blends of surfactants optimized for seawater or reservoir brine salinity include linear alkyl xylene sulfonate—alcohol ether sulfate mixtures (235). 

Surfactants evaluated in surfactant-enhanced alkaline flooding include internal olefin sulfonates (259,261), linear alkyl xylene sulfonates (262), petroleum sulfonates (262), alcohol ethoxysulfates (258,261,263), and alcohol ethoxylates/anionic surfactants (257). Water-thickening polymers, either xanthan or polyacrylamide, can reduce injected fluid mobiHty in alkaline flooding (264) and surfactant-enhanced alkaline flooding (259,263). The combined use of alkah, surfactant, and water-thickening polymer has been termed the alkaH—surfactant—polymer (ASP) process. Cross-linked polymers have been used to increase volumetric sweep efficiency of surfactant—polymer—alkaline agent formulations (265). 

L. Cavalli, A. Landone, and T. PeUizzan, "Linear Alkylation for Detergency—Characterization of Secondary Components," XIX Jomadas Del Comite Espanola De la Detergeneia, Barcelona, Spain, 1988, pp. 41—52. 

Estimates based on published and industry infomiation sources for production of linear alkyl (C 2) benzene alkylate sulfonic acid andlauryl-3 mol ethoxy... 

Ethoxylation of alkyl amine ethoxylates is an economical route to obtain the variety of properties required by numerous and sometimes smaH-volume industrial uses of cationic surfactants. Commercial amine ethoxylates shown in Tables 27 and 28 are derived from linear alkyl amines, ahphatic /-alkyl amines, and rosin (dehydroabietyl) amines. Despite the variety of chemical stmctures, the amine ethoxylates tend to have similar properties. In general, they are yellow or amber Hquids or yellowish low melting soHds. Specific gravity at room temperature ranges from 0.9 to 1.15, and they are soluble in acidic media. Higher ethoxylation promotes solubiUty in neutral and alkaline media. The lower ethoxylates form insoluble salts with fatty acids and other anionic surfactants. Salts of higher ethoxylates are soluble, however. Oil solubiUty decreases with increasing ethylene oxide content but many ethoxylates with a fairly even hydrophilic—hydrophobic balance show appreciable oil solubiUty and are used as solutes in the oil phase. 

Detergents. The most widely used surfactant in synthetic detergents is the readily biodegradable linear alkyl sulfonate (LAS). Since the... 

Plasticizers can be classified according to their chemical nature. The most important classes of plasticizers used in rubber adhesives are phthalates, polymeric plasticizers, and esters. The group phthalate plasticizers constitutes the biggest and most widely used plasticizers. The linear alkyl phthalates impart improved low-temperature performance and have reduced volatility. Most of the polymeric plasticizers are saturated polyesters obtained by reaction of a diol with a dicarboxylic acid. The most common diols are propanediol, 1,3- and 1,4-butanediol, and 1,6-hexanediol. Adipic, phthalic and sebacic acids are common carboxylic acids used in the manufacture of polymeric plasticizers. Some poly-hydroxybutyrates are used in rubber adhesive formulations. Both the molecular weight and the chemical nature determine the performance of the polymeric plasticizers. Increasing the molecular weight reduces the volatility of the plasticizer but reduces the plasticizing efficiency and low-temperature properties. Typical esters used as plasticizers are n-butyl acetate and cellulose acetobutyrate. 

Industrial chemicals, including those used for the manufacture of detergents such as linear alkyl benzene (LAB) and of coatings, dyestuffs, agrochemicals, pharmaceuticals, and explosives. 

Table 3.1-4 Effects of cation symmetry on the melting points of isomeric tetraalkylammonium salts. In each case the cation (designated [N op] ) has four linear alkyl substituents, together containing a total of 20 carbons. Salts that are liquid at room temperature are indicated by /.

Figure 3.1-4 shows the changes in liquefaction points (either melting points or glass transitions) for a series of l-allcyl-3-methylimida2olium tetrafluoroborate [26] and bis(trifyl)imide [45] ionic liquids with changing length of the linear alkyl-substituent on the N(3)-position. 

The production of linear alkyl benzenes (LABs) is carried out on a large scale for the production of surfactants. The reaction involves the reaction between benzene and a long-chain alkene such as dodec-l-ene and often gives a mixture of isomers. Greco et al. have used a chloroaluminate(III) ionic liquid as a catalyst in the preparation of LABs [83] (Scheme 5.1-53). 

Linear alkyl benzene sulfonates (LAS). Straight-chain anionic surfactants. Somewhat slow to biodegrade. Most common surfactants in use. 

The characteristic volume V/105 in m3/mol of the sodium sulfate ion is 4.966. The characteristic volume V/105 of the linear alkyl chain can be evalu-... 

Based on petrochemicals, linear alkyl benzene sulfonates (LAS) are the most important surfactants. First description can be found in patents from the mid-1930s [2] using Fischer-Tropsch synthesis and Friedel-Crafts reactions. With the beginning of the 1950s the importance of the class of surfactants rose. The main use is in household and cleaning products. 

Linear Alkyl Benzene from linear olefins with A1C13 catalyst, brochure, Enichem Augusta Industrial, Via Medici del Vascello 26, 20138 Milan, Italy. 

A thermally 1,5 Tf-shift induced by heating 1-ethoxy alkynes 60 to about 150°C led to ketenes 61. Subsequent cyclizations to give lactams 62 were achieved by attaching a M-benzamido function at C-6 or C-7 of a linear alkyl chain. Azepanones 62 (n = 1) and Azecanones 62 (n = 2) were generated in 68% and 58% yield, respectively. The formation of larger rings (n = 5,9) failed under the conditions reported (Scheme 12) [20]. 

Figure 4.6. General scheme for the synthesis of linear alkyl benzenes, precursors to surfactants. Control over pore size of the catalyst can suppress the second alkylation almost completely. Given the ease with which the pore size can be chosen, one can design an effective catalyst for any particular reaction, and allow the selective and clean production of the desired mono-alkyl product, thus eliminating much of the waste associated with the process.

In the case of terminal C=C (1,2 addition units), i.e. when R=R =H and R" (or R111) = polymer chain, two types of hydride migration are possible, namely (i) The Markownikoff s addition which would lead to the formation of B type repeating units and (ii) The anti Markownikoff s addition which would result in the formation of the observed repeating units C. In the case of Markownikoff s type addition the hydride transfer occurs to Ca and results in the formation of branched alkyl-rhodium intermediate complex shown by Structure 2. Whereas when anti Markownikoff s addition occurs, the resulting intermediate alkyl-rhodium complex has linear alkyl ligand as shown by Structure 3. 

Alkyl-substituted benzenes are oxidized both on the benzene ring and on the side chain. Additionally, some dimerization occurs.36 Alkylbenzenes containing linear alkyl groups are oxidized preferentially at the side chain33 nearest the benzene ring for example, ethylbenzene oxidizes first to 1-phenyl ethanol and then to acetophenone.36... 

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