DSTDP — Distearyl Thiodipropionate | CAS 693-36-7
Basic Information
| Property | Value |
|---|---|
| CAS Number | 693-36-7 |
| Chemical Name | Distearyl 3,3'-thiodipropionate |
| Molecular Formula | C42H82O4S |
| Molecular Weight | 683.16 g/mol |
| Appearance | White flakes or powder |
| Melting Point | 63–67 °C |
| Purity | ≥ 98% |
| Sulfur Content | 4.5–4.8% |
Introduction
Distearyl Thiodipropionate (DSTDP), CAS 693-36-7, is a high-performance secondary antioxidant of the thioester family. It functions by decomposing hydroperoxides formed during polymer oxidation, interrupting the degradation chain reaction at an early stage.
Unlike primary hindered phenolic antioxidants that scavenge free radicals, DSTDP operates through a peroxide-decomposing mechanism, making it a perfect synergist when combined with primary antioxidants such as Antioxidant 1010 or 1076.
DSTDP is the diester of 3,3'-thiodipropionic acid and stearyl alcohol. Its high molecular weight (683 g/mol) contributes to low volatility and excellent retention in polymer matrices during high-temperature processing.
Regulatory status: FDA 21 CFR 178.2010 compliant; EU 10/2011 food contact approved.
Key Applications
- Polyolefins (PP, HDPE, LDPE, LLDPE): Used at 0.1–0.3 phr, paired with Antioxidant 1010, protecting against thermooxidative degradation during compounding at 200–280°C
- Food Packaging: FDA and EU food contact compliant; widely used in polyolefin-based food contact films and containers
- Rubber & Elastomers: Protects SBR, NBR, and EPDM compounds from heat aging
- Adhesives & Hot-melt Systems: Extends shelf life and processing stability
- Lubricants & Greases: Long-term thermal stabilizer
- Wire & Cable Insulation: Improves heat-aging resistance
- Agricultural Films: Extends service life of greenhouse and mulch films
Synergistic Formulations
DSTDP works best paired with primary antioxidants. Recommended combinations:
| Primary Antioxidant | Typical Ratio (Primary:DSTDP) | Application |
|---|---|---|
| Antioxidant 1010 (CAS 6683-19-8) | 1:2 to 1:3 | PP, HDPE general purpose |
| Antioxidant 1076 (CAS 2082-79-3) | 1:2 | LDPE, LLDPE films |
| Antioxidant 1330 (CAS 1709-70-2) | 1:2 | High-temperature applications |
Packaging & Storage
- Packaging: 25 kg kraft paper bags with inner polyethylene liner
- Storage: Cool, dry, well-ventilated area below 30°C, away from direct sunlight
- Shelf life: 2 years from manufacturing date
- Transport: Non-hazardous, no special restrictions
FAQ
Q: What is the difference between DSTDP and DLTDP?
DSTDP uses stearyl alcohol (C18); DLTDP uses lauryl alcohol (C12). DSTDP has higher MW (683 vs 515 g/mol), higher melting point, and better retention at high temperatures. DLTDP has slightly better solubility at lower temperatures.
Q: Is DSTDP approved for food contact applications?
Yes. Listed in FDA 21 CFR 178.2010 and complies with EU Regulation 10/2011.
Q: What is the recommended dosage in polypropylene?
Typical: 0.1–0.3 phr DSTDP + 0.05–0.1 phr Antioxidant 1010. Optimal ratio depends on processing temperature and end-use requirements.
Q: What is the minimum order quantity (MOQ)?
Standard MOQ is 1 MT. Trial orders of 25–100 kg available for qualification. Contact us for pricing.
Q: Can Sunchem provide COA and MSDS?
Yes — full COA (purity, melting point, sulfur content, appearance) for every batch. MSDS and TDS available on request.