Dihexadecyl Peroxydicarbonate (CEPC, CAS 26322-14-5), a high-efficiency free-radical initiator, is revolutionizing low-temperature polymerization processes for PVC, acrylics, and specialty polymers. With the molecular formula C₃₄H₆₆O₆ and molecular weight of 570.9 g/mol, this organic peroxide delivers unparalleled control over molecular weight distribution while minimizing defects like "fish eyes" in industrial-scale production.
Technical Specifications & Physicochemical Properties
Parameter
Value
Physical State
White waxy flakes or powder (≥90% purity)
Melting Point
52–55°C
Density
0.936 g/cm³ (bulk density: 0.50 kg/L)
Solubility
Insoluble in water; soluble in acetone, hydrocarbons
Critical Safety Parameters:
Self-Accelerating Decomposition Temperature (SADT): 40°C
Half-Life (t₁/₂): 10h at 48°C, 1h at 65°C, 0.1min at 84°C
Active Oxygen Content: 2.52–2.69% (theoretical max: 2.80%)
UN Transport Class: 3116 (Type F organic peroxide)
Storage Stability: ≤6 months below 20°C; alarm temperature: 35°C .
Industrial Applications Driving Demand
1. PVC Production
As a low-temperature initiator, CEPC enables:
Reduced "Fish Eyes": ≤30% defect reduction in suspension PVC by controlling nucleation kinetics
Energy Efficiency: Polymerization at 45–60°C vs. 70–90°C for traditional peroxides
Co-polymer Compatibility: Optimizes vinyl chloride/acrylic blends for adhesive and coating resins
2. Acrylic & Styrenic Systems
Methyl Methacrylate (MMA): Achieves >95% conversion at 50°C with narrow polydispersity (Đ<2.0)
Composite Initiator Systems: Synergizes with dilauroyl peroxide for constant reaction rates in batch reactors
Synthesis Innovations: Cost-Efficient Manufacturing
A patented Chinese method (2022) boosts yield to ≥94% while cutting solvent use by 40% :
Reaction System: Sodium hydroxide (30–40%) + H₂O₂ (27–35%) with methanol cosolvent at 8–15°C
Dispersant Blend: Polyvinyl alcohol + fatty alcohol polyoxyethylene ether + sodium dodecyl sulfate (ratio 1:1:1)
Cetyl Chloroformate Addition: Controlled dosing at 18–25°C over 45–60 minutes
Purification: Dual washing with 30–50% methanol/water, vacuum drying at 25–28°C
✅ Efficiency Gains: 20% lower production costs vs. legacy methods; heavy metal residues <0.1 ppm Pb .
Safety Protocols: Non-Negotiable Handling Rules
CEPC’s low SADT (40°C) necessitates stringent protocols:
Storage: ≤20°C in PE containers; isolate from acids, metals, and amines
PPE Requirements: Butyl rubber gloves + full-face shields for handling solids
Emergency Response:
Fire: Use alcohol-resistant foam or CO₂ fog—water jets trigger explosive decomposition
Spills: Absorb with vermiculite/sand; store in ventilated plastic containers
⚠️ Regulatory Compliance:
China Hazard Code: 52092; GHS Classification: Type F peroxide (explosive when heated)
Future Innovations & Sustainability Trends
Bio-Based Dispersants: Replacing PVA with starch derivatives to reduce aquatic toxicity
Solid-State Stabilization: Nanoclay additives to extend shelf life at 25°C (patent pending)
Circular Economy Integration: Recycling PVC waste into CEPC-initiated recycled resins (pilot phase, 2026)
Dihexadecyl Peroxydicarbonate (CAS 26322-14-5) remains indispensable for high-precision polymerization, balancing reactivity control with evolving green chemistry solutions.