Dilauroyl peroxide (DLP), systematically named bis(1-oxododecyl) peroxide and identified by CAS number 105-74-8, is a critical organic peroxide widely leveraged in industrial chemistry. This white crystalline solid, with a molecular formula of C₂₄H₄₆O₄ and a molecular weight of 398.62 g/mol, serves as a cornerstone in polymer synthesis and material processing. Its unique structure─two lauroyl (dodecanoyl) chains bridged by a reactive peroxide bond (-O-O-)─enables controlled radical generation under thermal activation, making it indispensable across sectors.
I. Fundamental Properties & Structure
Physical Characteristics
Appearance: White granular or powdery solid with a faint characteristic odor.
Melting Point: 53–57°C; decomposes explosively above 60°C.
Density: 0.91 g/cm³ at 25°C.
Solubility: Insoluble in water; highly soluble in nonpolar solvents (e.g., chloroform, acetone, mineral oils) and partially soluble in alcohols.
Chemical Reactivity
The peroxide bond (-O-O-) undergoes homolytic cleavage at 40–70°C, generating lauroyloxyl radicals (C₁₁H₂₃COO•). These radicals initiate chain reactions, enabling:
Polymerization of vinyl monomers (e.g., ethylene, vinyl chloride).
Cross-linking of polyesters and rubbers.
Thermal Stability
Decomposes at >100°C, releasing volatile hydrocarbons and ketones. Critical safety note: Rapid decomposition occurs above 60°C, posing explosion risks.
Table 1: Key Physical Properties of Dilauroyl Peroxide
Property Value
CAS Number 105-74-8
Molecular Formula C₂₄H₄₆O₄
Molecular Weight 398.62 g/mol
Melting Point 53–57°C
Density (25°C) 0.91 g/cm³
Solubility in Water Insoluble
Stability Stable at <30°C; explosive >60°C
II. Synthesis & Industrial Production
DLP is synthesized via Schotten-Baumann reaction between lauroyl chloride and hydrogen peroxide:
Reaction Protocol:
Dissolve lauroyl chloride in petroleum ether.
Add aqueous NaOH and 6% H₂O₂ at <45°C with vigorous stirring.
Cool mixture with ice water; filter and wash crystals to neutrality.
Yield & Purity:
Industrial-grade DLP achieves ≥97% purity; high-purity grades (≥99%) are used in food/pharma applications.
III. Major Industrial Applications
A. Polymer Industry
Free-Radical Initiator
High-Pressure Polyethylene (LDPE): DLP initiates ethylene polymerization at 1,500–3,000 atm, controlling molecular weight distribution.
Polyvinyl Chloride (PVC): Combined with di-tert-butyl peroxide to optimize suspension polymerization kinetics.
Polypropylene Modification: Enhances melt flow index via controlled degradation.
Curing & Cross-Linking Agent
Unsaturated Polyesters: Accelerates resin hardening in fiberglass composites.
Rubber Vulcanization: Improves elasticity and heat resistance in synthetic rubbers.
B. Food & Consumer Goods
Edible Oil Bleaching: Degrades carotenoids in palm/coconut oils (≤0.05% w/w).
Cosmetic Products: Acne creams (e.g., benzoyl peroxide alternatives) at <5% concentration.
C. Specialty Uses
Foaming Agent: Generates N₂/CO₂ in polymeric foams.
Drying Catalyst: For alkyd paints and coatings.
Table 2: Industrial Applications of Dilauroyl Peroxide
Industry Function Examples
Polymer Manufacturing Free-radical initiator LDPE, PVC, polystyrene
Materials Processing Cross-linking agent Rubber, polyurethane foams
Food Technology Bleaching agent Vegetable oils, flour
Cosmetics Antimicrobial agent Acne treatments, hair products
IV. Safety & Regulatory Compliance
Hazard Profile
Explosivity: Classified as UN 3106 (5.2 Organic Peroxide); detonates under heat/shock.
Health Risks: Skin/eye irritant; IARC classifies as Group 3 carcinogen (limited evidence).
Storage & Handling
Store at 2–8°C under water or inert gas (N₂/Ar).
Avoid contact with reductants, heavy metals, and acids to prevent runaway reactions.
Regulatory Status
EPA TSCA: Listed for commercial use.
EU REACH: Requires explosion-proof processing.
V. Future Outlook
DLP remains vital for high-pressure polymer synthesis, though alternatives like di-tert-butyl peroxide offer better thermal stability. Emerging roles in nanomaterial functionalization and recyclable elastomers are under research. Sustainable synthesis methods─using enzyme-catalyzed peroxidation─may address ecological concerns.
Dilauroyl peroxide (CAS 105-74-8) exemplifies how molecular simplicity enables industrial versatility. From creating food-safe plastics to refining edible oils, its reactive prowess demands equal respect for chemistry and caution. As industries prioritize greener processes, innovations in peroxide stabilization and delivery will define DLP’s next chapter.