Sulfuric Acid, Mono-C16-18-alkyl Esters, Sodium Salts
Time: 2012-09-25 16:59:31
Sulfuric Acid, Mono-C16-18-alkyl Esters, Sodium Salts
Synonyms
Sodium mono-C16-18-alkyl sulfates;
Sodium C16-18 alkyl sulfate;
Sodium Cetostearyl Sulfate;
C16-C18 alkyl alcohol sulfuric acid sodium salt;
Category
Anionic Surfactant
>> Sulfate
>> Chain Alcohol Sulfate
>> Alkanol Sulfate
>> Linear Alkanol Sulfate
Chemical Numbering System
CASRN: 68955-20-4
EINECS: 273-258-7
Molecular Formula & Molecular Weight
Molecular Formula: C16H33NaO4S - C18H37NaO4S; C16H34O4S.Na - C18H38O4S.Na (SciFinder Hill Rules)
Molecular Weight: 344.49 - 372.54
Structure
R: C16-18.
Properties
Appearance    white powder.
Odor    faint characteristic odor.
Solubility    slightly soluble in water. soluble in ethanol.
Physical - chemical properties
Flash point, °C
> 93
Stability    stable in alkali, weak acid and hard water; unstable in strong acid, hydrolyzed, reduced to alcohol.
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:  
Ecology    may be hazardous to environment. Water body should be given special attention.
Biodegradability    biodegradable.
Characteristics    excellent cleansing, emulsifying, foaming, dispersing, solubilizing abilities. Especially, under high temperatures, has foaming and cleansing effects. Resistant to hard water.
Note    (1), Avoid using in children cleaning products, such as shower gels, shampoo, skin care products.
Synthesis
Currently, sulfated reaction through continuous reactor (such as: falling film reactor) is the most widely used method for preparing sulfates.
Generally, C16-18 alkyl alcohol and sulfur trioxide react through reactor, then sodium hydroxide 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 alcohols or other raw materials: 1:1; temperature: 30-60°C; reactor: falling film reactor.
US patent 6,455,488 (Process of making alkyl sulfate granulates) describes the preparation of a particulate alkyl sulfate, but does not involve the synthesis process.
US patent US 6,331,645 (Process for preparing powdery alkyl sulfates) describes the preparation of a powdery alkyl sulfate, but does not involve the synthesis process.
Quality Standards & Test Methods
1. Physical and chemical indexes
Item
Physical and chemical indexes
Solid
Actives, %, ≥
90
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. Hazardous substances indexes
Item
Hazardous substances indexes
Solid
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), Generally, sodium C16-18 alkyl sulfate and sodium stearyl sulfate replace to use each other.
Major Uses
1. Typical applications
Use as cleansing agent.
Use as cleansing agent, foaming agent under high temperature conditions.
2. Household detergents
Cleansing agent in laundry detergent and other household products.
3. Industrial cleaning agents
Cleansing agent in car cleaning products, metal cleaning products and other industrial cleaning products.
4. Pets
Cleansing agent, emulsifying agent in shampoos and other pet products.
Manufacturers
 
Update: 20131018(1); 20160826(2);