Sodium dodecylbenzene sulfonate
Time: 2012-09-28 16:23:35
Sodium dodecylbenzene sulfonate
Synonyms
Sodium lauryl benzene sulfonate;
Dodecylbenzene sulfonic acid, sodium salt;
Sodium dodecylbenzene sulfonate;
Dodecyl benzene sulfonic acid sodium salt;
Sodium dodecyl benzene sulphonic acid salt;
Sodium laurylbenzene sulfonate;
LAS;
DBS;
Category
Anionic Surfactant
>> Sulfonate
>> Aryl Sulfonate
>> Phenyl Sulfonate
>> Linear Alkylphenyl Sulfonate
Chemical Numbering System
CASRN25155-30-0
EINECS246-680-4
Molecular Formula & Molecular Weight
Molecular Formula: C18H29NaO3S; C18H30O3S.Na
Molecular Weight: 348.48
Structure
Properties
Appearance    (1), liquid; (2), slurry; (3), white to slightly yellow powder.
Solubility    soluble in water.
Hygroscopicity    highly hygroscopic agglomerate. Not easy to restore into powder, after the agglomeration.
Physical - chemical properties
Water solubility, g/L
0.8 (20 - 25°C)[1]
Log Kow (octanol - water)
0.45[1]
Stability    stable.
Risk    Solid form: flammable material; irritation, moderate irritation to skin, eye, respiratory. Harmful products of combustion are CO, CO2 and so on. Contact with strong oxidants, can cause to burn.
GHS (Rev.6) label:  
Liquid form: irritation, moderate irritation to skin, eye.
GHS (Rev.6) label:
Skin irritation: rabbit: concentration of less than 1%, will not cause skin irritation[2].
Eye irritation: rabbit: concentration of less than 0.01%, will not cause eye irritation[2].
Animal Toxicity
Table 1 Animal toxicity values
rat oral LD50
438mg/kg[3]
mouse oral LD50
1330mg/kg[3]
mouse intravenous LD50
105mg/kg[3]
Ecology    may be hazardous to environment. Water body should be given special attention.
Biodegradability    biodegradable.
Characteristics    excellent cleansing, foaming, emulsifying, wetting, dispersing, solubilizing abilities. Weak resistance to hard water, used in conjunction with chelating agent. Good compatibility. The most commonly used alkylbenzene sulfonate
Note    (1), Avoid using in children cleaning products, such as shower gels, shampoo.
(2), Sodium dodecylbenzene sulfonate (linear chain), may not be substituted branched dodecylbenzene sulfonate.
(3), Due to potential hazards on reproductive system of straight-chain sodium dodecylbenzene sulfonate, can be not recommended to use in food field, for example: fruit and vegetable cleaning agent, dishwasher cleaning agent.
(4), Sodium dodecyl benzene sulfonate is divided into two types of hard and soft. Hard sodium dodecyl benzene sulfonate is branched alkyl benzene sulfonate, referred to as ABS. ABS can not easily be biodegradable; has serious harm to aquatic organisms, especially fish; has certain reproductive toxicity. Therefore, many countries have stopped production of ABS. Soft sodium dodecylbenzenesulfonate is linear alkylbenzene sulfonate, referred to as LAS. LAS can be biodegradable.
(5), Commercially available dodecylbenzene, is mixture of isomers, alkyl group distribution mainly is between C10-13/14, average alkyl length is approx 12; due to limitation of catalyst used, n-dodecylbenzene does not exist. Therefore, structure of commercially available sodium dodecyl benzene sulfonate:
Among them: x+y=8 - 9.
Synthesis
Currently, sulfonation reaction through continuous reactor (such as: falling film reactor) is the most widely used method for preparing sulfonates.
Generally, dodecylbenzene and sulfur trioxide react through reactor, then sodium hydroxide or sodium carbonate neutralizes, finally obtain product.
US patent 8,921,588 (Process for preparing sulfates and/or sulfonates in a micro-reaction system) presents a synthetic process. Conditions: mole ratio of sulfur trioxide and alkyl benzenes or other raw materials: 1:1; temperature: 30-60°C; reactor: falling film reactor.
Quality Standards & Test Methods
1. Physical and chemical indexes
Item
Physical and chemical indexes
Appearance
Actives, %
pH (25°C, 1%)
20 type
pale transparent liquid; or solid
20±2
7.5 - 11.0
30 type
liquid; or solid
30±2
7.5 - 11.0
40 type
liquid; or solid
40±2
7.5 - 11.0
50 type
slurry; or solid
50±2
7.5 - 11.0
60 type
solid
60±2
7.5 - 11.0
70 type
solid
70±2
7.5 - 11.0
80 type
solid
80±2
7.5 - 11.0
90 type
solid
90±2
7.5 - 11.0
Test Methods
(1), Actives
GB/T 5173 Surface active agents and detergents-Determination of anionic-active matter by direct two-phase titration procedure
ISO 2271 Surface active agents -- Detergents -- Determination of anionic-active matter by manual or mechanical direct two-phase titration procedure
(2), pH
GB/T 6368 Surface active agents - Determination of pH of aqueous solution - Potentiometric method
ISO 4316 Surface active agents -- Determination of pH of aqueous solutions -- Potentiometric method
2. Hazardous substances indexes
Item
Hazardous substances indexes
Heavy metals (as Pb), mg/Kg, ≤
20
As, mg/Kg, ≤
3
Test Methods
(1), Heavy metals (as Pb)
Safety and Technical Standards for Cosmetics (2015 Edition)
GB/T 30799 The test method of food detergents - Determination of heavy metals
(2), As
Safety and Technical Standards for Cosmetics (2015 Edition)
GB/T 30797 The test method of food detergents - Determination of total arsenic
3. Further explanation
(a), On physical and chemical indexes: firstly, shall be indicated carbon atom distribution; secondly, shall be indicated average molecular weight.
(b), Used in cosmetics, should be test for harmful substances; or furtherly test for microorganisms.
Major Uses
1. Typical applications
Use as cleansing agent.
Use as emulsifying agent, dispersing agent.
2. Household detergents
Main ingredient or auxiliary ingredient for cleansing agent, foaming agent in laundry detergent, household hard surface detergent and other household products.
One of the most typical applications.
3. Industrial cleaning agents
Use as cleansing agent.
4. Emulsion polymerization
Emulsifier, particle size controlling agent in emulsion polymerization.
Particularly suitable for pressure-sensitive adhesive polymerization.
5. Personal care products
Use as cleansing agent, emulsifying agent. Not recommended.
6. Pesticide
Emulsifying agent, dispersing agent, anti-caking agent in pesticide.
7. Textile
Antistatic agent, cleansing agent in textile.
8. Petroleum
Foaming agent, crude oil demulsifier in petroleum.
9. As an anti-caking agent
Used in urotropine, urea and other organic powder products;
Used in ammonium nitrate, ammonium chloride and other inorganic powder products.
10. Pets
Use as cleansing agent, emulsifying agent, foaming agent.
Manufacturers
 
References
[1]: HSDB. 25155-30-0, Sodium dodecylbenzenesulfonate
[2]: OECD. Linear alkylbenzene sulfonate (LAS). SIDS Initial Assessment Report for 20th SIAM. 2005.
[3]: ChemIDplus. 25155-30-0, Sodium dodecylbenzenesulfonate
[4]: Trivedi S P, Kumar M, Mishra A, etal. Impact of linear alkyl benzene sulphonate (LAS) on phosphatase activity in testis of the teleostean fish, Heteropneustes fossilis (Bloch) (J) . Environ Biol, 2001, 22 (4): 263 - 266
Update: 20131025(1); 20170308(2);