Introduction
Dilauroyl peroxide, also known as lauroyl peroxide or LPO (CAS 105-74-8), is a symmetrical diacyl peroxide derived from lauric acid (dodecanoic acid). As a solid organic peroxide with moderate thermal stability, LPO finds widespread use as a polymerization initiator, crosslinking agent, and bleaching agent across the polymer, food, and cosmetic industries.
Key Facts: Dilauroyl Peroxide
- CAS Number: 105-74-8
- Molecular Formula: C24H46O4
- Molecular Weight: 398.62 g/mol
- Appearance: White powder or flakes
- Melting Point: 53-57 deg C
- Active Oxygen: 4.01% (theoretical)
- 10-Hour Half-Life: ~62 deg C
- 1-Hour Half-Life: ~80 deg C
Physical Properties
| Property | Value |
|---|---|
| Appearance | White powder or flakes |
| Active Oxygen Content | 3.8-4.0% (commercial grade) |
| Density | ~0.9 g/cm3 |
| Solubility in Water | Insoluble |
| Solubility in Organics | Soluble in benzene, chloroform, oils; slightly soluble in alcohols |
| SADT | ~50 deg C |
Applications
1. PVC Polymerization
LPO serves as a low-to-medium temperature initiator for PVC suspension and mass polymerization. Its decomposition kinetics in the 50-70 deg C range make it suitable for general-purpose PVC grades and copolymer production.
2. Polyethylene Crosslinking
In peroxide-crosslinked polyethylene applications, LPO can function as a co-initiator alongside higher-temperature peroxides, helping to extend the radical generation profile and optimize crosslink uniformity.
3. Food Industry
LPO has historically been used as a flour bleaching and maturing agent, though regulatory restrictions have limited this application in many jurisdictions. Its decomposition products are primarily carbon dioxide and lauric acid, which are relatively benign.
4. Silicone Curing
LPO is employed as a curing agent for certain silicone elastomer formulations, particularly where lower cure temperatures are desired compared to DCP or BIPB systems.
Safety and Storage
LPO is classified as an Organic Peroxide Type D (UN 3106). Key handling precautions include storage below 30 deg C, avoidance of contamination, and use of explosion-proof equipment. Water-wet or phlegmatized formulations provide enhanced safety during transport and handling.
Frequently Asked Questions
Q: How does LPO compare to benzoyl peroxide as a polymerization initiator?
A: LPO has a lower 10-hour half-life temperature (~62 deg C) compared to BPO (~73 deg C), making it more reactive at lower temperatures. LPO’s decomposition products (CO2 and lauric acid/undecane derivatives) are generally less aromatic and odorous than BPO’s decomposition products. However, LPO has lower active oxygen content (4% vs. 6.6%), requiring higher dosage by weight for equivalent radical generation.
Q: Is LPO suitable for food contact applications?
A: LPO’s use in food-related applications varies by jurisdiction. While it has been used for flour treatment historically, regulatory approvals should be verified for the specific application and region. The decomposition products (lauric acid being a natural fatty acid) are relatively benign, but comprehensive migration and safety data must support any food-contact use.
Key Takeaways
- Dilauroyl peroxide (LPO, CAS 105-74-8) is a diacyl peroxide with moderate thermal stability (T10h ~62 deg C).
- Key applications include PVC polymerization, polyethylene crosslinking, and silicone curing.
- Its decomposition produces relatively benign fragments (CO2, lauric acid derivatives).
- LPO requires temperature-controlled storage and standard organic peroxide handling precautions.
- Shandong Do Sender Chemicals supplies high-quality LPO for industrial polymerization applications.