Alkylbenzenesulfonates disulfonate

AOS is a complex mixture of different chemical species. A typical product composition is as follows [1-7] sodium alkenesulfonate (60-70%) sodium hydroxyalkanesulfonate (30%) sodium disulfonate (0-10%) 6- or 1, 4-sultone (50 ppm) unsulfonated matter (less than 2%) and inorganic salt (mainly sodium sulfate, less than 2.5%). AOS can therefore be regarded as a surfactant system in contrast with other common surfactants such as alkyl sulfates, alkyle-thoxy sulfates, alkanesulfonates, and alkylbenzenesulfonates, which consist of mixtures of their isomers and/or homologs. 

Figure 3 illustrates the detergency performance of a linear C,g alkyidiphenyl oxide disulfonate compared to a typical monosulfonated surfactant, Cjj linear alkylbenzenesulfonate. The alkyidiphenyl oxide disulfonate was observed to yield a higher detergency score than the monosulfonated surfactant over a broad concentration range. The results illustrated in Figure 3 represent a direct comparison between a mono- and disulfonated surfactant in an unformulated system at a hardness level of 150 ppm Ca. ... 

FIG. 3 Comparison of the detergency performance of linear alkylbenzenesulfonate and Cj alkyldiphenyl oxide disulfonate. The detergency comparison was conducted at 25°C using a Tergotometer and dust/sebum-soiled swatches of cotton, cotton/polyester, and polyester. Clean swatches of each fabric type were also included to measure redeposition. The detergency score is a summation of reflectance deltas of the clean and soiled swatches before and after washing. 

FIG. 7 Mols of surfactants rinsed from cotton skeins as a function of time. Disulfonate = Cjg alkyldiphenyl oxide disulfonate monosulfonate = Cj Unear alkylbenzenesulfonate nonionic = nonyl phenol ethoxylate (EO = 9). All rinsability studies were conducted at ambient temperature. 

The alkyidiphenyl oxide disulfonates are considered moderate foamers. While foam can be generated upon agitation of the surfactant solution, the foam profile tends to be lower than that of many other common monosulfonated surfactants. Figure 8 illustrates modified Ross-Miles [17] foam profiles of the C,2 linear alkylbenzenesulfonate and of Cjg alkyidiphenyl oxide disulfonate. The disulfonated surfactant was observed to yield a lower foam profile over the entire range of conditions evaluated. The foam profile of the disulfonated surfactant, Cjg alkyidiphenyl oxide disulfonate, varies with the solution in which it is solubilized. For example, the initial foam height of the disulfonated surfactant in the presence of 5% sodium hypochlorite is approximately one-half of that observed in deionized water (Table 1). 

FIG. 8 Modified Ross-Miles foam heights for C,2 linear alkylbenzenesulfonate and alkyldiphenyl oxide disulfonate at varying levels of Ca. Mono = linear alkylbenzenesulfonate Di = Cjg alkyldiphenyl oxide disulfonate. T = 0 represents the initial foam height. T = 5 represents the foam height after 5 min. 

Commercial-grade Cjg aUcyldiphenyl oxide disulfonate was compared to commercial grade linear alkylbenzenesulfonate sodium salt and a commercial... 

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