Dodecylbenzene, branched

Microbes could not break down branch-chain detergents, so they left foam in river water. They were replaced by straight-chain alkyl benzene sulfonates, such as sodium dodecylbenzene-sulfonate and sodium xylenesulfonate. 

The general procedure for dispersion involves use of sonication, which causes an unzipping mechanism of dispersion as proposed by Smalley and co-workers [51]. Typical surfactants used for this purpose are sodium dodecylsulfate (SDS) or sodium dodecylbenzene sulfonate (SDBS). The latter shows a stronger interaction as a result of the presence of the aromatic ring. It also appears that longer and more branched hydrocarbon chains interact more efficiently [52],... 

Derivation Benzene is alkylated with dodecene, to which it attaches itself in any secondary position the resulting dodecylbenzene is sulfonated with sulfuric acid and neutralized with caustic soda. For ABS (branched-chain alkyl) the dodecene is usually a propylene tetramer, made by catalytic polymerization of propylene. For LAS (straight-chain alkyl), the dodecene may be removed from kerosene or crudes by molecular sieve, may be formed by Ziegler polymerization of ethylene, or by cracking wax paraffins to a-olefins. 

In the early 1960s, it became obvious that dodecylbenzene-based detergents were contributing to the pollution of lakes and streams. The reason for this was the poor biodegradability of the highly branched propylene tetramer aliphatic chain. This caused detergents discharged from water treatment plants to maintain their surfactant properties and form relatively stable foams.f ... 

Branched dodecylbenzene is produced by alkylation of polymer tetramer and benzene. The polymer tetramer feedstock is produced in a propylene oligomerization plant using a process such as the UOP catalytic condensation process. Benzene feedstock is typically produced by solvent extraction of reformate or pygas by means of an aromatics extraction process. There is no detailed discussion of DDB production in this entry, as the production of SDBS has been almost entirely phased out. A complete discussion is presented in Ref.. ... 

An alternative anionic wetting agent is sodium dodecylbenzene sulphonate, with a branched alkyl chain... 

On the other hand, the introduction of some branching into the hydrophobic group increases the CMC/C20 ratio but has little effect on Ym. We can therefore expect that the introduction of branching into the hydrophobic group will make the surfactant a more effective surface tension reducer. This is seen in the isomeric p-dodecylbenzene-sulfonates (Figure 5-4), where the isomers with branched alkyl chains, although less efficient reducers of the surface tension than the isomer with the straight alkyl chain, reduce the surface tension to lower values than does the latter. 

Chem. Descrip. Sodium dodecylbenzene sulfonate, branched CAS 25155-30-0 EINECS/ELINCS 246-680-4 Uses Emulsifier for styrene polymerization paints/coatings food pkg, adhesives, rubber articles defoamer in food-contact paper/paperboard emulsifier in mfg. of food-contact articles Reguiatory FDA 21CFR 175,105, 176,210, 177.2600, 178,3130,... 

Chem. Descrip. Dodecylbenzene sulfonic acid, branched CAS 27176-87-0 EINECS/ELINCS 248-289-4 Uses Intermediate for the prod, of sodium salts neutralized acid as emulsifier salts as emulsifiers for SBR latex emulsion polymerization paints/ coalings catalyst for acid catalyzed reactions defoamer in food-contact paper/paperboard emulsifier in mfg. of food-contact articles Regulatory EDA 21CER 176.210,178.3400 Properties Dk. vise, liq. water-sol. dens. 9.1 Ib/gal sp.gr. 1.09 vise. 9000 cps (30 C) anionic 97.4% act. 

Chem. Descrip. Branched sodium dodecylbenzene sulfonate CAS 25155-30-0 EINECS/ELINCS 246-680-4 Uses Emulsifier for emulsion polymerization (SBR, vinyl acetate, vinyl chloride, styrene, and acrylic latexes), paints/coatings emulsifier, dispersant for agric. formulations surfactant for washing fruits and vegetables food pkg. adhesives, paper defoamer in food-contact paper/ paperboard emulsifier in mfg. of food-contact articles Regulatory FDA 21 CFR 175.105,175.300,175.320,176.170,176.180, 176.200,176.210,178.3400 exempt from tolerance under EPA40CFR 180.1001 (c) (e) BGA XIV compliance Properties Flakes pH 6.0-9.5 (10%) surf. tens. 32 dynes/cm ( CMC) anionic 98% act. 

Sodium ali lhenzene sulfonate, branched. See Sodium dodecylbenzene-sulfonate... 

Synonyms Benzenesulfonic acid, dodecyl-, sodium salt Dodecylbenzene sodium sulfonate Dodecylbenzenesulfonate, sodium salt Dodecyl-benzenesulfonic acid sodium salt NaDBS SDBS Sodium alkylben-zene sulfonate, branched Sodium lauryl benzene sulfonate ClassiTication Substituted aromatic compd. 

In contrast to TPS with its branched alkyl chain, n-dodecylbenzene sulfonate exhibits an extremely fast rate of biodegradability. The change-over from a branched to a straight-chain structure is easily achieved, and thus by the use of Ziegler synthesis and molecular-sieve extraction techniques, industrial processes for the production of linear olefines and -alkanes soon became readily available. These are the basic starting materials for the synthesis of linear alkylbenzene derivatives. 

The branched alkylbenzenes, produced predominantly between 1950 and 1970, were obtained from propylene tetramer and benzene at temperatures from 20 to 50 °C, with a reaction time of a few minutes, using Friedel-Crafts catalysts (HF or AICI3). To avoid polyalkylation as far as possible, the operation was carried out with a 5 to 10-fold excess of benzene. The yield of dodecylbenzene was 70 to 80%. 

Isopropyl amine branched dodecylbenzene sulfonate % Concentration 88 Pale, clear viscous liquid POLYSTEP A-15 ... 

Branched sodium dodecylbenzene sulfonate % Concentration 30 Pale, turbid liquid POLYSTEP A-16-22 ... 

Branched dodecylbenzene sulfonic acid % Concentration 97 Dark viscous liquid... 

Surfactant types C EO = C H2 i(OCH2CH2) OH AOT = sodium bis-diethylhexyl sulfosuccinate C TAB = C H2 +j (CH3)3N Br . Ci26( )S03Na = sodium 6-phenyl dodecylbenzene sulfonate Ci2sodium dodecylbenzene sulfonate (branched chain blend) APG = commercial Ci2/i4(glucopyranoside)i2 Cj2E025S04Na = commercial sodium dodecyl-polyoxyethylene-2.5-sul-fate C12APB = commercial dodecyl amino-propyl betaine. 

Abe and Matsumnra [108] have also considered the antifoam effect of alcohols on the foam behavior of an aqueous solution of sodium dodecylbenzene sulfonate. The alcohols inclnded normal alcohols, branched alcohols, and diols. However, Abe and Matsumura [108] were concerned with the supposed role of the elimination of surface tension gradients under dynamic conditions in determining heterogeneous antifoam effectiveness in the case of these weakly polar oils. We have of course already considered the basic proposition of antifoam action by elimination of surface tension gradients in some detail in Section 4.4.3. 

FIGURE 4.28 Effect of addition of 0.01 wt.% of various emulsified alcohols on the foam-ability and foam stability of 2.6 mM aqueous saline solution of a branched chain sodium dodecylbenzene sulfonate blend (using the dynamic Ross-Miles technique at 25-27°C). (Reprinted with permission from Amaudov, L. et al. Langmuir, 17, 6999. Copyright 2001 American Chemical Society.)... 

Surfactant types Ci2sodium dodecylbenzene sulfonate (branched-chain blend) AOT, sodium bis-diethylhexyl sulfosuccinate Triton X-100, octyl phenol decaethylene glycol ether ... 

Chem. Descrip. Branched sodium dodecylbenzene sulfonate CAS 25155-30-0 EINECS/ELINCS 246-6804... 

Chem. Descrip. Branched calcium dodecylbenzene sulfonate Ionic Nature Anionic... 

Chem. Descrip. Calcium dodecylbenzene sulfonate (branched) in isobutanol... 

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