CAS 131538-00-6 | 4-Mercaptomethyl-3,6-dithia-1,8-octanedithiol | Polythiol for High-Refractive-Index Optical Resins | China Manufacturer
Product Name: 4-(Mercaptomethyl)-3,6-dithia-1,8-octanedithiol
Synonym: Polythiol 504, 2,3-Bis[(2-sulfanylethyl)sulfanyl]-1-propanethiol
CAS Number: 131538-00-6
Molecular Formula: C7H16S5
Molecular Weight: 260.53
Purity: ≥ 99%
Thiol Content: ~35%
Appearance: Colorless to pale yellow liquid
Refractive Index: 1.607 (predicted)
Packaging: 1kg / 25kg / 200kg / 1000kg (custom available)
Lead Time: 3-7 business days from stock
Made in China | COA & SDS provided with every shipment
- Worldwide Delivery
- Quality Assurance
- 24/7 Customer Service
Product Introduction
CAS 131538-00-6 | 4-Mercaptomethyl-3,6-dithia-1,8-octanedithiol | Polythiol for High-Refractive-Index Optical Resins | China Manufacturer
|
🧪 Purity
≥ 99%
High purity grade
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⚖️ Thiol Content
~35%
Typical value
|
🔬 Refractive Index
1.607
Predicted value
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🧊 Appearance
Colorless Liquid
Pale yellow tint
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Product Overview
As a China-based manufacturer, Alfa Chemical supplies high-purity 4-(Mercaptomethyl)-3,6-dithia-1,8-octanedithiol (CAS 131538-00-6), a trifunctional polythiol with three reactive thiol groups. Also known as Polythiol 504, this organosulfur compound features a propane backbone functionalized with three thiol groups, two of which are connected via ethylthio linkages. The five sulfur atoms in a relatively compact C7 molecule give it a high refractive index, making it a valuable monomer for optical applications.
The compound is supplied as a colorless to pale yellow liquid with a purity of ≥ 99% and a typical thiol content of ~35%. Its three terminal thiol groups are the primary sites of reactivity, enabling the molecule to act as a potent cross-linking agent or as a ligand for metal ions. In particular, it is a key monomer in the synthesis of high-refractive-index polythiourethane resins, which are widely used in optical applications such as thinner and lighter eyeglass lenses. It also serves as an effective epoxy resin curing agent and a heavy metal ion capture agent.
We offer flexible packaging from 1kg R&D samples to 1000kg bulk quantities with fast worldwide delivery. For similar organic building blocks and specialty reagents, explore our related product range.
Key Features
Three reactive thiol groups enable efficient crosslinking with isocyanates and epoxy resins, delivering high crosslink density and mechanical strength.
Five sulfur atoms in a compact C7 structure provide a high refractive index (predicted 1.607), ideal for optical polythiourethane resins.
Typical thiol content of ~35% ensures efficient reaction with isocyanates and epoxy groups at low dosage.
≥99% purity with consistent quality. Each batch includes a Certificate of Analysis with detailed purity and thiol content data.
Available from 1kg R&D samples to 1000kg bulk drums. Reliable supply chain with 3-7 day delivery worldwide.
Applications
High-prescription lenses made from standard resins are thick and heavy. Formulators need a monomer with a higher refractive index.
✅ Solution: Polythiol 504 as polythiourethane lens monomer
Five sulfur atoms provide high refractive index. Reacts with isocyanates to form a transparent, high-refractive-index polythiourethane network, making lenses thinner and lighter.
Request technical data →Formulators need room-temperature fast curing with high crosslink density and excellent mechanical properties.
✅ Solution: Polythiol 504 as epoxy curing agent
Three thiol groups react rapidly with epoxy groups, enabling room-temperature curing with high crosslink density for coatings and adhesives.
Get formulation advice →Trifunctional structure enables efficient crosslinking of polymers, improving mechanical properties and thermal stability.
Request a sample →Thiol groups effectively capture heavy metal ions for environmental applications. Also used as an extreme-pressure anti-wear additive in lubricants.
Request a quote →Product Specifications
Detailed specifications for 4-(Mercaptomethyl)-3,6-dithia-1,8-octanedithiol (CAS 131538-00-6) are listed below. For batch-specific COA or SDS, please contact us.
| Item | Specification |
|---|---|
| Product Name | 4-(Mercaptomethyl)-3,6-dithia-1,8-octanedithiol |
| Synonym | Polythiol 504, 2,3-Bis[(2-sulfanylethyl)sulfanyl]-1-propanethiol |
| CAS Number | 131538-00-6 |
| EINECS Number | 411-290-7 |
| Molecular Formula | C₇H₁₆S₅ |
| Molecular Weight | 260.53 g/mol |
| Purity | ≥ 99% |
| Appearance | Colorless to pale yellow liquid |
| Thiol Content | ~35% (typical) |
| Density | 1.214 g/cm³ |
| Refractive Index | 1.607 (predicted) |
| Boiling Point | ~395.6 °C (predicted) |
| Flash Point | 193.0 °C (predicted) |
| Storage Condition | Sealed in dry environment at 2-8°C |
| Shelf Life | 24 months (under recommended storage) |
| Packaging Options | 1kg / 25kg / 200kg / 1000kg, custom available |
| Documents | COA (purity, thiol content), SDS |
Every shipment includes COA and SDS. Click below to request batch-specific documents or technical data for CAS 131538-00-6:
Manufacturing & Quality Control
Alfa Chemical operates a dedicated facility for organosulfur compounds and polythiols. Our 4-(Mercaptomethyl)-3,6-dithia-1,8-octanedithiol is synthesized under controlled conditions to ensure high purity (≥99%), consistent thiol content, and reliable performance across all batches.
Each batch is tested in-house for purity, thiol content, density, and appearance. A Certificate of Analysis (COA) and Safety Data Sheet (SDS) are provided with every shipment. Learn more about our facilities →
Packaging & Shipping
- Packaging Options: 1kg / 25kg / 200kg / 1000kg drums, custom packaging on request
- Shipping Methods: International express courier for sample quantities; air freight or sea freight for bulk orders
- Delivery Time: 3-7 business days after payment confirmation
- Documentation: COA and SDS provided with every shipment
- For special packaging or urgent requests, please contact our team directly.
Why Choose Alfa Chemical
- 10+ years focused on organosulfur compounds and specialty reagents
- Experienced R&D and QC team with expertise in polythiol synthesis and purification
- In-house QC – purity, thiol content, and density verified, batch-traceable COA
- Flexible supply – 1kg for R&D up to 1000kg for production
- China manufacturer direct – competitive pricing with full COA/SDS traceability
- Explore more organic building blocks or contact us for custom requirements.
Frequently Asked Questions
It is used as a monomer for high-refractive-index optical resins, an epoxy resin curing agent, a polymer crosslinking agent, and a heavy metal capture agent.
Our product has a purity of ≥99% with a typical thiol content of ~35%. Each batch includes a Certificate of Analysis (COA).
The stoichiometric ratio depends on the NCO content of your isocyanate. The thiol content (~35%) can be used to calculate the exact amount. Technical support is available upon request.
The predicted refractive index is 1.607. Actual values may vary slightly by batch. COA includes measured refractive index where applicable.
Store in a sealed container in a dry environment at 2-8°C. Avoid moisture and direct sunlight. Shelf life is 24 months under proper storage.
Standard MOQ is 1kg for R&D samples and 200kg for production quantities. Contact us for custom quantities.
Related products & resources:
* All product specifications are for reference purposes. Users should conduct their own suitability tests under actual conditions. This product is for industrial manufacturing and R&D use only. Not for food, pharmaceutical, or cosmetic applications without specific regulatory compliance testing.
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