4-Hydroxybenzenesulfonic acid

Chemical properties

yellowish oily liquid

The Uses of 4-Hydroxybenzenesulfonic acid

4-Hydroxybenzenesulfonic Acid is used as a redox-mediator in the laccase-catalyzed degradation of indigo, a textile dye. Also used in oilfield chemicals, metal working, and as a polymerization catalyst.

Definition

ChEBI: An arenesulfonic acid that is phenol substituted by a sulfo group at C-4.

Production Methods

The synthesis of 4-Hydroxybenzenesulfonic acid is as follows：Phenol (25 kg) and 96% sulfuricacid(28 kg) are heated to 50 ℃; then1.25 kg additional sulfuric acid is added and the reaction mixture is heated at 110 ℃ for 5 – 6 h. Reaction water, together with about 5% of the phenol, is distilled off during this period. Yield 95%.

What are the applications of Application

Crude 4-hydroxybenzenesulfonic acid obtained by hot sulfonation, i.e., mixed with 2- hydroxybenzenesulfonic acid, is used as such in the manufacture of synthetic tanning agents. Condensation products of phenolsulfonic acid mixtures with formaldehyde improve the dyeing properties of polyamide fibers. 4-Hydroxybenzenesulfonic acid and 2-halogenomalonic esters form the corresponding ethers, which are used in the manufacture of polyesters with improved affinity for basic dyes. If a mixture of hydroxybenzenesulfonic acids and bis(hydroxyphenyl) sulfone is condensed with formaldehyde, and hydrogensulfite is subsequently added, substances with good dispersing effects on dyes are obtained. They also are used as thinning agents for cement. Most of the 4-hydroxybenzenesulfonic acid is used as an additive for electroplating baths. By comparison, the acid is relatively unimportant as a dye intermediate. With ethylene oxide it forms poly(ethoxy)oxybenzenesulfonic acid, which can be used as a plasticizer and emulsifier.

Flammability and Explosibility

Non flammable