Introduction
Di-n-butyl peroxydicarbonate (CAS 16215-49-9), also referred to as NBP or DNBPD, is a peroxydicarbonate initiator with n-butyl substituents. Its relatively simple, short-chain structure makes it one of the more reactive peroxydicarbonates, suitable for low-temperature PVC polymerization processes.
Key Facts
- CAS Number: 16215-49-9
- Molecular Formula: C10H18O6
- Molecular Weight: 234.25 g/mol
- Appearance: Colorless to pale yellow liquid
- Active Oxygen: ~6.8% (theoretical)
- 10-Hour Half-Life Temperature: ~41-43 deg C
- SADT: ~5-10 deg C
- Storage: Deep refrigerated, typically -15 to -20 deg C
Physical and Chemical Properties
| Property | Value |
|---|---|
| Appearance | Colorless to pale yellow liquid |
| Density (20 deg C) | ~1.05-1.10 g/cm3 |
| Active Oxygen | ~6.8% (theoretical) |
| Solubility in VCM | Excellent |
| SADT | ~5-10 deg C |
| UN Classification | UN 3115 (Organic Peroxide Type D, liquid, temperature controlled) |
Applications
Low-Temperature PVC Production
Di-n-butyl peroxydicarbonate is used as a low-temperature initiator for suspension PVC, particularly for resin grades requiring K-values in the 68-72 range. Its decomposition kinetics provide efficient radical generation at reactor temperatures of 45-55 deg C, with relatively low levels of residual peroxide at the end of the polymerization cycle.
Combination Initiator Systems
NBP is often used as part of a dual or triple initiator system alongside higher-temperature peroxides (peroxyesters, diacyl peroxides) to optimize the radical generation profile throughout the polymerization exotherm, improving reactor productivity and product consistency.
Safety and Storage
Deep refrigerated storage (-15 to -20 deg C) is mandatory. Cold chain integrity must be maintained from manufacturer through to point of use. All handling must follow Class 5.2 protocols with explosion-proof equipment, temperature monitoring, and comprehensive emergency response planning.
Frequently Asked Questions
Q: How does NBP compare to EHP for PVC initiation?
A: NBP has a slightly lower 10-hour half-life temperature (~41-43 deg C vs. ~43-44 deg C for EHP), making it marginally more reactive. Its higher active oxygen content (6.8% vs. 4.6%) means that less NBP is required by weight to achieve equivalent radical generation. The n-butyl substituent is simpler and smaller than the 2-ethylhexyl group, which can influence solubility and partitioning behavior in the polymerization system.
Q: What are the storage temperature requirements for NBP?
A: NBP must be stored at temperatures between -15 and -20 deg C in explosion-proof refrigeration units. Storage areas must have continuous temperature monitoring with alarm systems, backup power for refrigeration, and emergency procedures for temperature excursions. The maximum recommended storage duration should be strictly observed, typically 3-6 months from manufacture under proper conditions.
Key Takeaways
- Di-n-butyl peroxydicarbonate (CAS 16215-49-9) is a reactive peroxydicarbonate initiator with a T10h of ~41-43 deg C.
- Higher active oxygen content (6.8%) compared to EHP allows lower weight dosage.
- Deep refrigerated storage and strict cold chain management are essential for safety.
- Shandong Do Sender Chemicals supplies NBP as part of its comprehensive peroxydicarbonate portfolio.