H1: 3-Mercaptopropionic Acid (3-MPA) — Industrial Grade
Quick Facts
| Property | Detail |
|---|---|
| Chemical Name | 3-Mercaptopropionic Acid |
| Synonyms | 3-MPA, β-Mercaptopropionic Acid, Thiohydracrylic Acid |
| CAS Number | 107-96-0 |
| Molecular Formula | C₃H₆O₂S |
| Molecular Weight | 106.14 g/mol |
| Appearance | Colorless to pale yellow liquid |
| Purity | ≥99.0% |
| Primary Use | Chain transfer agent for PCE superplasticizer synthesis |
| Packaging | 250 kg drum / IBC / ISO tank |
What is 3-Mercaptopropionic Acid?
3-Mercaptopropionic Acid (3-MPA, CAS 107-96-0) is a bifunctional organosulfur compound featuring both a thiol group (–SH) and a carboxylic acid group (–COOH). This dual reactivity makes 3-MPA the industry-preferred chain transfer agent (CTA) in the free-radical polymerization of polycarboxylate ether (PCE) superplasticizers — the backbone chemical for modern high-performance concrete.
When used at typical dosages of 0.5%–2.0% relative to monomer weight, 3-MPA precisely controls molecular weight and PDI (polydispersity index) of the PCE polymer backbone, directly governing the plasticizing performance and slump retention of the finished concrete admixture.
Technical Specifications
| Parameter | Specification |
|---|---|
| Purity (GC) | ≥99.0% |
| Moisture | ≤0.1% |
| Color (APHA) | ≤20 |
| Density (20°C) | 1.218 g/mL |
| Boiling Point | 111°C @ 10 mmHg |
| Flash Point | 110°C |
| Refractive Index | 1.4834 |
| Sulfur Content | ≈30.2% |
| Acidity (as COOH) | ≥99.0% |
Primary Application: PCE Superplasticizer Synthesis
In PCE manufacturing, 3-MPA serves as a molecular weight regulator. During free-radical copolymerization of acrylic acid and PCE macromonomer (TPEG/HPEG/APEG), 3-MPA donates its thiol hydrogen to growing polymer radicals, terminating chain growth and producing a new radical that reinitates polymerization.
Result: Narrower molecular weight distribution, consistent PCE performance batch-to-batch.
Typical process parameters:
- Dosage: 0.5%–2.0% (wt/wt relative to monomers)
- Reaction temperature: 40°C–80°C
- Reaction medium: Aqueous solution
Other Industrial Applications
- Gold & precious metal extraction — thiol groups chelate metal ions selectively
- Cross-linking agent — for epoxy and polyurethane systems
- PVC stabilizer intermediate — mercapto-organotin synthesis
- Surface modifier — functionalization of quantum dots and nanoparticles
- Pharmaceutical intermediates — thiol-functionalized compounds
Why Source 3-MPA from Definly Chemicals?
Consistent ≥99.0% purity — every batch tested by GC before shipment; CoA issued as standard.
PCE industry expertise — we supply 3-MPA alongside PCE macromonomer (TPEG/HPEG/APEG) and 2-HEA, allowing you to source your entire PCE raw material requirement from one supplier.
Competitive pricing — direct factory supply, no trading company markup.
Reliable logistics — Qingdao port access, FCL/LCL, door-to-door DDP available.
Technical support — our team can advise on optimal 3-MPA dosage for your specific PCE molecular weight target.
Packaging & Shipping
| Option | Net Weight | Suitable For |
|---|---|---|
| Plastic drum | 250 kg | Sample / trial orders |
| IBC tank | 1,000 kg | Regular production |
| ISO tank | 20,000 kg | Large-volume supply |
Stored in cool, dry, ventilated area away from oxidizers. Shelf life: 12 months from production date.
Frequently Asked Questions
Q: What is the typical 3-MPA dosage in PCE synthesis? A: The standard dosage is 0.5%–2.0% by weight relative to total monomer mass. Lower dosages (0.5–1.0%) yield higher molecular weight PCE suited for high water-reduction applications; higher dosages (1.5–2.0%) produce lower MW PCE for slump retention profiles.
Q: How does 3-MPA differ from 2-mercaptoethanol or dodecyl mercaptan as a CTA? A: 3-MPA offers superior water solubility (miscible with water) and the carboxylic acid group provides additional anchoring sites in the PCE chain, improving cement particle dispersibility. Dodecyl mercaptan is oil-soluble and unsuitable for aqueous PCE polymerization.
Q: What is the minimum order quantity? A: Sample orders start from 250 kg (one drum). Standard commercial orders start from 1 MT.
Q: Can you provide a Certificate of Analysis (CoA)? A: Yes. A batch-specific CoA showing GC purity, moisture, color, and density is issued with every shipment.
Q: What is the shelf life of 3-MPA? A: 12 months when stored in original sealed containers, below 30°C, away from light and oxidizers.
Q: Is 3-MPA classified as hazardous for shipping? A: Yes. 3-MPA is classified as UN 2921 / Class 6.1, PG III for international shipping. We handle all MSDS documentation and dangerous goods declaration.
Q: Do you supply other PCE synthesis raw materials? A: Yes — we also supply PCE Macromonomer (TPEG, HPEG, APEG) and 2-Hydroxyethyl Acrylate (2-HEA). Contact us for a bundled quote.
Q: What payment terms do you accept? A: T/T (30% deposit, 70% before shipment) is standard. L/C is available for orders above 5 MT.
Related Products
- PCE Macromonomer (TPEG / HPEG / APEG) — /products/pce-macromonomer/
- 2-Hydroxyethyl Acrylate (2-HEA) — /products/2-hydroxyethyl-acrylate/
- Polycarboxylate Superplasticizer (PCE) — /products/polycarboxylate-superplasticizer/
Request a Quote
Looking for a reliable 3-MPA supplier? Contact Definly Chemicals for pricing, samples, and technical support.
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