Introduction
1,1,3,3-Tetramethylbutyl peroxy-2-ethylhexanoate (CAS 22288-43-3), also known as tert-octyl peroxy-2-ethylhexanoate (TOPEH), is a peroxyester initiator combining the branched tert-octyl group with the 2-ethylhexanoate ester. This structural combination provides a distinctive reactivity profile suited to specific polymerization and curing applications.
Key Facts
- CAS Number: 22288-43-3
- Molecular Formula: C16H32O3
- Molecular Weight: 272.43 g/mol
- Appearance: Colorless to pale yellow liquid
- Active Oxygen: ~5.9% (theoretical)
- 10-Hour Half-Life Temperature: ~44-48 deg C
- SADT: ~15-20 deg C
- Storage: Refrigerated, typically below 0 deg C
Physical Properties
| Property | Value |
|---|---|
| Appearance | Colorless to pale yellow liquid |
| Density | ~0.90 g/cm3 |
| Solubility in Monomers | Excellent in styrene, VCM, acrylates, ethylene |
| SADT | ~15-20 deg C |
Applications
PVC Polymerization
TOPEH serves as a low-to-medium temperature initiator for suspension PVC, with decomposition kinetics suitable for the 45-60 deg C reactor temperature range.
LDPE Production
In high-pressure LDPE processes, TOPEH can function as an initiator in specific reactor zones where medium-temperature radical generation is required.
Acrylic and Specialty Polymers
The initiator is also applicable to acrylic and other vinyl monomer polymerization processes.
Safety
TOPEH requires refrigerated storage (below 0 deg C) due to its SADT of ~15-20 deg C. Cold chain integrity, temperature monitoring, and standard organic peroxide handling protocols are essential.
Frequently Asked Questions
Q: How does TOPEH differ from TBPEH (tert-butyl peroxy-2-ethylhexanoate)?
A: The primary difference is the alkyl substituent: TBPEH uses a tert-butyl group while TOPEH uses a 1,1,3,3-tetramethylbutyl (tert-octyl) group. The larger, more branched tert-octyl group provides more steric hindrance and modified solubility characteristics. The decomposition products differ, with TOPEH generating tert-octyloxy radicals instead of tert-butoxy radicals, which can influence initiation efficiency and polymer end-group chemistry.
Key Takeaways
- 1,1,3,3-Tetramethylbutyl peroxy-2-ethylhexanoate (CAS 22288-43-3) is a peroxyester initiator with a T10h of ~44-48 deg C.
- The branched tert-octyl group provides steric and solubility advantages.
- Applications include PVC, LDPE, and acrylic polymerization.
- Shandong Do Sender Chemicals supplies this initiator for specialized polymerization processes.