Sodium decyl sulphonate

With ionic surfactants, the solubility first increases gradually with rising temperature, and then, above a certain temperature, there is a very sudden increase of solubility with further increase in temperature [4, 5]. Figure 3.7 illustrates this with the results for sodium decyl sulphonate in water. The same figure also shows the variation of c.m.c. with temperature [4, 5]. The solubility of the surfactant clearly increases rapidly above 22 °C. The c.m.c. increases gradually with increasing temperature. 

Fig. 3.7. Solubility and c.m.c. versus temperature for sodium decyl sulphonate in water. ( ) solubility, ) c.m.c.

Figure 4.17 Phase diagram near the Krafft point of sodium decyl sulphonate. [From K. Shonda and E. Hutchinson,/. Phys. Chem., 66, 577, Copyright (1962) American Chemical Society]...

Gutfelt et al. (1997) have evaluated various ME formulations as reaction media for synthesis of decyl sulphonate from decylbromide and sodium sulphite. The reaction rate was fast both in water-in-oil and in bicontinuous ME based on non-ionic surfactants. A comparison was made with this reaction being conducted in a two-phase. system with quats as phase-transfer catalyst but was found to be much less efficient. However, when two other nucleophiles, NaCN and NaNOj, were used the PTC method was almost as efficient as the ME media. It seems that in the case of decyl sulphonate there is a strong ion pair formation between the product and the PTC. The rate in the ME media could be further increased by addition of a small amount of a cationic surfactant. 

The purpose of this paper is to give a brief summary of an Investigation which has been carried out into the aqueous-phase polymerisation of butadiene initiated by cobalt(III) acetylacetonate In the presence of surfactants such as sodium dodecylbenzene-sulphonate and sodium decyl sulphate. It is Intended that fuller details of the investigation will be published elsewhere in due course. 

Surfactants Ionic, anionic (e.g., sodium dodecyl sulphate, Cj2H250S03 Na ), cationic (e.g., cetyl trimethyl ammonium chloride, Ci,H33-N+(CH3)3C1-), zwitterionic [e.g., 3-dimethyldodecylamine propane sulphonate (betaine CJ2H25-N" (CH3)2-CH2-CH2-CH2-S03)], nonionic, alcohol ethoxylates C H2 +i-0-(CH2-CH2-0) -H, alkyl phenol ethoxylates C H2 +i-CgH4-0-(CH2-CH2-0) -H, amine oxides (e.g., decyl dimethyl amine oxide, C10H21-N ( 113)2 0), and amine ethoxylates. 

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