Dodecylbenzene sulphonic acid

An example of a highly exothermic reaction carried out in this manner is provided by the manufacture of dodecylbenzene sulphonic acid. The reactor is charged with dodecylbenzene and 20% oleum is fed in continuously at a rate which is regulated to give a uniform temperature during the sulphonation reaction. The conversion is thus effectively controlled by the rate of oleum addition rather than the rate of the chemical reaction. 

Nacure 5225 is a blocked dodecylbenzene sulphonic acid cure catalyst made by King Industries. Surfonyl 465 is a surfactant produced by Air Products. 

Ko et al. [110] have carried out electrochemical studies of chemically synthesized dodecylbenzene sulphonic acid (DBSA) doped polyaniline in a non-aqueous electrolyte such as propylene carbonate containing LiC104. According to these authors, electrochemical cycling of polymer films reduces the crystal-... 

The hydrolysis of carbohydrates in dodecylbenzene sulphonic acid in dioxane-water mixtures has been the subject of one study in which it Was found that the hydrolysis was accelerated by about 21 times in dioxane mixtures above 60% by volume [126], but no coherent mechanism was put forward for the catalysis. Non-ionic surfactants may form inverse micelles in non-aqueous solvents in the presence of small amounts of water. Triton X-1(X), for example, micellizes in carbon tetrachloride on addition of water. This system, which obviously does not suffer the problems which result from the dissociation of the head groups of ionic surfactants in the water pool, has been used to investigate the hydration reaction of acetaldehyde [127]. This acid-catalysed reaction is increased by a factor of 10000 over that in water (Table 11.9). In spite of the nonionic nature of the peripheral head groups surrounding and penetrating the aqueous core, the nature of the water is such that ionization of solubilized species is changed. 

An example of the separation of the anilides of the eight lowest straight-chain carboxylic acids on sodium dodecylbenzene sulphonate is shown in Fig. 5.14. The problem of the procedure described above consists in that formanilide cannot be prepared as CO, SO2 and HC1 are produced by the action of thionyl chloride on formic acid. Formanilide must, therefore, be prepared in an aqueous medium, the other acids must be extracted into a non-aqueous medium. The yield of the extraction varies considerably depending on the type of the acid, and the presence of water in the reaction medium may affect the reaction yield significantly, which makes quantitative analysis difficult. Condensates with toluidine, which were used for the determination of formic acid by GC, are prepared by an analogous procedure. As other toluidine isomers may serve as the reagents, formyl derivatives have been suggested for the separation of these substances [181]. 

Fig. 5.14. Separation of anilide derivatives of Cj -Cs straight-chain carboxylic acids. Peaks 1 = propionic 2 = n-butyric 3 = acetic 4 = n-valeric 5 = n-hexanoic 6 = formic and n-heptanoic 7 = n-octanoic acid STD = methyl myristate. Conditions glass column, 12 ft. x 3 mm I.D., 2.5% (w/w) sodium dodecylbenzene sulphonate on Chromosorb G (60-80 mesh, NAW) nitrogen inlet pressure, 15 p.s.i. temperature, 200°C. (Reproduced from/. Chromatogr., 51 (1970) 147.)...

Makowska, D., Sobczynska, A., Zimoch, J., Szymanowski, J. 2001. Interfacial activity of ethoxyethyl-ated fatty acid methyl esters. Mixtures with sodium dodecylbenzene sulphonate. Proceedings XXXI Jornadas Anuales del CID. Barcelona, 325-336. 

A large number of surfactants have been used in the preparation of conducting and magnetic composites principally based on PANI and PPy, such as dodecyl benzene sulphonic acid (DBSA) [39, 40, 45, 70, 71], sodium dodecylbenzene sulfonate (NaDS) [24, 72], sodium dodecyl sulfate (SDS) [18, 31, 73-75],... 

The dodecylbenzene that has formed is passed to the sulphonation section, where alkylaryl sulphonate is formed. The unreacted sulphuric acid is recycled. 

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