2-Mercaptopropionic Acid丨CAS 79-42-5

Overview

2-Mercaptopropionic acid丨CAS 79-42-5 is an organosulfur compound with both a carboxylic acid and a thiol group. This dual functionality makes it a versatile intermediate in polymer chemistry, pharmaceuticals, agrochemicals, and electroplating. It is a clear to pale yellow liquid with a strong thiol odor, and is highly reactive due to the thiol group.

Applications

1. Polymer Industry

Chain transfer agent (CTA) in radical polymerization, especially in the synthesis of:

Acrylic resins

Emulsion polymers

Waterborne coatings

Regulates molecular weight and polymer architecture (e.g., controlling branching and dispersity).

2. Pharmaceutical Intermediate

Used in the synthesis of API building blocks, including:

Penicillin derivatives

Chelating agents

Thiol-modified biomolecules

3. Electroplating & Metal Surface Treatment

Acts as a brightener and leveling agent in copper and nickel electroplating baths.

Improves adhesion and corrosion resistance of metal surfaces.

4. Cosmetic Industry

Occasionally found in hair care formulations (such as perms or straighteners) as a reductant, though usage is limited due to odor and sensitization risk.

5. Analytical & Specialty Chemicals

Used to prepare chelating agents and thiol-functional reagents for:

Metal ion complexation

Enzyme modification

Gold nanoparticle stabilization

Benefits

✅ Dual Functionality

Possesses both acidic and nucleophilic properties, allowing diverse reactivity for synthetic applications.

✅ Efficient Radical Transfer

The thiol group provides excellent control in free radical polymerizations, enabling better control over polymer size and properties.

✅ Versatile Building Block

Its structural simplicity allows it to be incorporated or transformed into a variety of sulfur-containing bioactive molecules.

✅ Enhanced Surface Performance

In metal treatment, it improves uniformity, brightness, and conductivity of coatings.

✅ Biocompatibility (Conditional)

With proper formulation, it can be used in applications involving biomaterials and thiolated bio-conjugates.

Summary

2-Mercaptopropionic acid丨CAS 79-42-5 is a valuable thiol-containing compound widely used in polymer synthesis, metal finishing, and as a pharmaceutical intermediate. Its ability to act as both a radical transfer agent and chelating ligand makes it a multifunctional ingredient across industrial and research sectors.