Perodox® PD - Di(2,4-dichlorobenzoyl) peroxide

CAS 133-14-2 refers to Di(2,4-dichlorobenzoyl) peroxide, also known as bis(2,4-dichlorobenzoyl) peroxide or DCBP.

The molecular formula is C₁₄H₆Cl₄O₄ with a molecular weight of 380.01 g/mol.

It typically appears as a white to off-white crystalline powder or as a gray-white uniform paste when formulated with silicone oil.

The melting point is 118-122°C with decomposition occurring at these temperatures.

The density ranges from 1.18 to 1.26 g/cm³ at 20°C, depending on the formulation and purity.

No, it has very low water solubility (29.93 μg/L at 25°C) but is soluble in organic solvents like chlorinated hydrocarbons and esters.

The theoretical active oxygen content is 4.21%, with commercial products typically containing 4.2-4.5% active oxygen.

The vapor pressure is 0.009 Pa at 25°C, indicating low volatility under normal conditions.

The log P value is 6 at 20°C, indicating high lipophilicity.

Common synonyms include DCBP, bis(2,4-dichlorobenzoyl) peroxide, 2,4-dichlorobenzoyl peroxide, and Perkadox OPC-50S-PS (commercial name).

The primary application is as a crosslinking agent (vulcanizing agent) for silicone rubber, particularly for high-temperature vulcanization (HTV) processes.

It is typically used at 1.1-2.3% concentration based on silicone rubber weight, enabling crosslinking at temperatures between 110-130°C under pressure or at 150-400°C in continuous hot air systems.

Yes, one of its key advantages is that it allows pressureless vulcanization using hot air or infrared systems, unlike some other peroxides that require pressure.

It serves as a radical initiator for polymerization of vinyl and acrylic monomers in PVC, rubber, and specialty plastics production, and as a crosslinking agent for polyester resins.

Yes, it functions as an intermediate in the synthesis of antibiotics, agrochemicals, and other pharmaceutical compounds through its role as a radical source in organic synthesis.

Its crosslinking is not inhibited by oxygen, allowing for pressureless vulcanization processes, and it provides good heat resistance and mechanical properties in the cured rubber.

It is used in manufacturing low-voltage power cable rubber materials, oil-resistant flame-retardant cables for petroleum platforms, and other specialized cable insulation.

The recommended addition is 1.1-2.3% of the silicone rubber weight to achieve the desired degree of crosslinking, depending on the specific formulation and application requirements.

Yes, it is used in specialized adhesive systems requiring controlled crosslinking, particularly where heat-activated curing is desired.

Optimal crosslinking occurs in the range of 110-130°C under pressure, or 150-400°C in continuous pressureless systems, with typical crosslinking at 90°C achieving t90 of approximately 12 minutes.

The SADT is 60°C, meaning self-accelerating decomposition can occur above this temperature, requiring strict temperature control during storage and handling.

The safe processing temperature is 65°C, where the rheometer ts2 (time to 2-point rise) is greater than 20 minutes, providing a safe processing window.

Half-life values are: 0.1 hour at 80°C, 1 hour at 65°C, and 10 hours at 47°C, indicating its temperature-dependent decomposition kinetics.

Available as ≥98% pure crystalline powder or as 49-52% active paste in silicone oil (typically 50% formulation for easier handling and mixing).

Moisture content is typically ≤1.5% (Karl Fischer method) to ensure stability and prevent premature decomposition.

Particle size is typically ≤50 μm for uniform dispersion and consistent performance in polymer formulations.

Major decomposition products include carbon dioxide (CO₂), 1,3-dichlorobenzene, 2,4-dichlorobenzoic acid, and traces of 2,2',4,4'-tetrachlorobiphenyl.

The Control Temperature is 50°C, which is the maximum temperature at which it can be stored without special precautions.

The Emergency Temperature is 55°C, at which immediate cooling measures must be implemented to prevent thermal runaway.

It offers high radical yield at 80-120°C with low residue generation, and its oxygen-insensitive crosslinking makes it unique for pressureless vulcanization applications compared to many other peroxides.

UN 3106, Organic Peroxide, Type D, indicating it is a thermally unstable substance that may undergo self-accelerating decomposition.

Key precautions include: avoiding heat sources (keep below 30°C), preventing contact with reducing agents/acids/bases/heavy metals, using appropriate PPE, and ensuring adequate ventilation.

Recommended PPE includes chemical-resistant gloves, protective clothing, safety goggles or face shield, and appropriate respiratory protection if dust or vapors are present.

The acute oral toxicity LD₅₀ in mice is 225 mg/kg (intraperitoneal), classifying it as harmful if swallowed and requiring careful handling to prevent ingestion.

Use dry sand, dry chemical powder, or alcohol-resistant foam. Water spray can be used to cool containers and prevent reignition, but avoid direct water stream on burning material.

Immediately remove contaminated clothing and wash skin thoroughly with soap and water for at least 15 minutes. Seek medical attention if irritation persists.

Incompatible with reducing agents (amines), acids, bases, heavy metal compounds (accelerators, driers, metal soaps), and combustible materials. These can cause violent decomposition or fire.

Store at or below 30°C in a cool, well-ventilated area away from heat sources and direct sunlight. Refrigerated storage (2-8°C) is recommended for extended periods.

It is hazardous to aquatic environments and can cause long-term adverse effects. Prevent release to waterways and soil. Decomposition products include chlorinated compounds that may persist in the environment.

When stored below 30°C in original sealed containers, it typically maintains specification for 3-6 months. For longer storage, refrigeration at 2-8°C is recommended.

Commercial names include Perodox PD, and various manufacturer-specific designations for 50% paste formulations in silicone oil.

Available in 1 kg lab bottles, 20 kg fiber cans with inner PE bags, 25 kg polyethylene-lined steel drums, 50 kg PE drums, and up to 500 kg IBC containers for bulk quantities.

Yes, Di(2,4-dichlorobenzoyl) peroxide (CAS 133-14-2) is listed on the U.S. Toxic Substances Control Act (TSCA) Inventory.

The EINECS (European Inventory of Existing Commercial Chemical Substances) number is 205-094-9.

It is classified as UN 3106, Organic Peroxide, Type D, Packing Group II, requiring DG (Dangerous Goods) certification, thermal stability reports, and compliance with IMDG, IATA, and ADR/RID regulations.

Commercial products typically comply with ISO 9001 quality management standards and may meet pharmaceutical intermediate production standards depending on grade and manufacturer.

Production ranges from laboratory scale (kg quantities) to industrial scale (100 kg to 100 metric tons annually), with most commercial production at multi-ton scale.

Common methods include HPLC for purity, Karl Fischer titration for moisture, GC for residual solvents, DSC/TGA for thermal properties, and iodometric titration for active oxygen content.

The paste form is desensitized, safer to handle, easier to mix and homogenize with polymers, provides better dispersion, and reduces dust exposure compared to pure powder.

Post-curing at 150-250°C for 12-24 hours is recommended to remove acidic decomposition products and improve aging resistance of the cured silicone rubber.

Upon thermal decomposition, it generates 2,4-dichlorobenzoyloxy radicals that initiate polymerization or abstract hydrogen atoms to create polymer radicals for crosslinking.

Chlorine substitution increases thermal stability, raises decomposition temperature, reduces oxygen inhibition during crosslinking, and modifies solubility characteristics compared to unsubstituted benzoyl peroxide.

At 90°C, the typical induction time (time to onset of crosslinking) is 2-5 minutes, with complete crosslinking (t90) achieved in approximately 12 minutes under standard conditions.

Caution is required as it is sensitive to carbon blacks, which can affect decomposition kinetics and potentially generate polychlorinated biphenyls (PCBs) during crosslinking.

Key differences include: higher decomposition temperature (118-122°C vs. ~100°C for DCP), oxygen-insensitive crosslinking, different decomposition products, and specific compatibility with different silicone polymer types.