p-Toluene Sulphonic Acid
Synonyms
4-methylbenzenesulfonic acid;
p-Toluenesulfonic acid;
Toluene-4-sulphonic acid;
Tosic Acid;
PTSA;
Category
Anionic Surfactant
> Sulfonate
>> Aryl Sulfonate
>>> Phenyl Sulfonate
>>>> Linear Alkylphenyl Sulfonate
Chemical Numbering System
CAS: 104-15-4
EINECS: 203-180-0
Molecular Formula & Molecular Weight
Molecular Formula: C7H8O3S
Molecular Weight: 172.20
Structure
Properties
Appearance (1), white crystal; (2), liquid.
Solubility soluble in water; soluble in alcohol.
Hygroscopicity hygroscopic.
Physical - chemical properties
|
Water solubility, g/L Water |
About 670 (Not specified temperature)[1] |
|
Melting point, °C |
106 - 107[1] |
Stability stable.
Risk Solid form: flammable material; corrosion; irritation, moderate irritation to skin, eye. Harmful products of combustion are CO, CO2 and so on. Contact with strong oxidants, can cause to burn.
GHS label: 
Liquid form: corrosion; irritation, moderate irritation to skin, eye.
GHS label:
Animal Toxicity
Table 1 Animal toxicity values
|
rat oral LD50 |
2480mg/kg[2] |
|
quail oral LD50 |
> 316mg/kg[2] |
|
rat oral LD50 |
400mg/kg[1] |
|
rat intravenous LD50 |
70mg/kg[1] |
|
mouse intravenous LD50 |
160mg/kg[1] |
Ecology may be hazardous to environment. Water body should be given special attention.
Biodegradability biodegradable.
Characteristics excellent hydrotropic, viscosity reducing, pour point depressing, anti-caking, dispersing, emulsifying, cleansing abilities. Commonly use as acidic catalyst in organic synthesis. Non-oxidizing organic strong acid. Paper and wood can be carbonized.
Synthesis
Currently, sulfonation reaction through continuous reactor (such as: falling film reactor) is the most widely used method for preparing sulfonates.
Generally, p-toluene and sulfur trioxide react through reactor, 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 |
|
|
Liquid |
Solid |
|
|
Actives, %, ≥ |
30.0 - 80.0 |
98.0 |
|
pH (25°C, 1%), < |
3.0 |
3.0 |
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 |
|
|
Liquid |
Solid |
|
|
Heavy metals (as Pb), mg/kg, ≤ |
20 |
20 |
|
As, mg/kg, ≤ |
3 |
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 hydrotrope.
Use as auxilialy emulsifying agent, auxilialy dispersing agent.
Use as cleansing agent, pickling agent.
Prepare alkali metal salt or amine salt of p-toluenesulfonic acid.
2, Household detergents
Use as hydrotrope, cleansing agent.
3, Industrial cleaning agents
Use as hydrotrope, cleansing agent.
4, Personal care products
Use as hydrotrope.
5, Pets
Use as hydrotrope.
6, Organic Synthesis
Use as acidic catalyst.
Manufacturers
References
[1]: HSDB. 104-15-4, p-Toluenesulfonic acid
[2]: ChemIDplus. 104-15-4, p-Toluenesulfonic acid
Update: 20131025(1); 20170310(2);