Introduction
tert-Butyl perpivalate (TBPP), CAS 29240-17-3, also known as tert-butyl peroxypivalate, is a peroxyester initiator characterized by the pivalate ester group. The tert-butyl substituent adjacent to the peroxy functional group, combined with the sterically hindered pivalate moiety, provides a distinctive balance of reactivity, thermal stability, and handling characteristics.
Key Facts
- CAS Number: 29240-17-3
- Molecular Formula: C9H18O3
- Molecular Weight: 174.24 g/mol
- Appearance: Colorless to pale yellow liquid
- Active Oxygen: ~9.2% (theoretical)
- 10-Hour Half-Life Temperature: ~55 deg C
- SADT: ~20-25 deg C
- Storage: Refrigerated, typically 0-10 deg C
Chemical Characteristics
TBPP’s relatively high active oxygen content (~9.2% theoretical) means that less material is required per unit of radical generation compared to initiators with lower active oxygen. The pivalate ester group decomposes to yield tert-butyl radicals and pivalate-derived fragments, which have minimal impact on polymer properties.
Applications
PVC Polymerization
TBPP is used as a medium-temperature initiator for PVC suspension polymerization. Its decomposition kinetics in the 50-65 deg C range complement those of lower-temperature initiators (peroxydicarbonates) and higher-temperature initiators (other peroxyesters), making it a valuable component of multi-initiator systems that optimize polymerization rate profiles.
LDPE Production
In high-pressure LDPE processes, TBPP can serve as a medium-temperature initiator in certain reactor zones, contributing to controlled radical flux for polymer molecular weight development.
Acrylic and Specialty Polymers
TBPP is also applicable as an initiator for acrylic, methacrylic, and other vinyl monomer polymerization processes.
Safety
TBPP requires refrigerated storage (0-10 deg C). Standard organic peroxide handling protocols apply, including explosion-proof equipment, PPE, and spill management procedures.
Frequently Asked Questions
Q: How does TBPP compare to tert-butyl peroxybenzoate (TBPB)?
A: TBPP has a significantly lower 10-hour half-life temperature (~55 deg C vs. ~104 deg C for TBPB), making it suitable for lower-temperature processes. Its active oxygen content (~9.2%) is higher than TBPB (~8.2%), providing more efficient radical generation per unit weight. The pivalate decomposition products differ from TBPB’s benzoate-derived fragments, which may influence polymer properties in some applications.
Key Takeaways
- TBPP (CAS 29240-17-3) is a medium-temperature peroxyester initiator with high active oxygen content.
- Its T10h of ~55 deg C fills the gap between peroxydicarbonates and higher-temperature peroxyesters.
- Applications include PVC, LDPE, and acrylic polymer production.
- Shandong Do Sender Chemicals supplies high-quality TBPP for demanding polymerization applications.