Dicumyl peroxide (DCP), CAS 80-43-3, is a white crystalline organic peroxide used as a high-temperature radical initiator for crosslinking polyethylene, degrading polypropylene and curing rubber and unsaturated polyester. PolyBlueChem supplies DCP at peroxide content 99% min and active oxygen 5.80% min. Because dicumyl peroxide is listed as an explosive precursor in China, export requires a licence and an end-use declaration – see the regulatory section below before ordering.
Specifications
| Property | Specification |
|---|---|
| Appearance | White powder |
| Peroxide content (%) | Min 99.0 |
| Active oxygen (%) | Min 5.80 |
| Packaging | 20-25 kg fibre drum or carton with inner liner; chilled transport recommended |
Basic Information
| Chemical name | Dicumyl peroxide; bis(1-methyl-1-phenylethyl) peroxide |
| Abbreviation | DCP |
| CAS number | 80-43-3 |
| Chemical class | Dialkyl organic peroxide (di-cumyl type) |
| Appearance | White crystalline powder |
| Peroxide content | Min 99% |
| Active oxygen | Min 5.80% |
| Function | High-temperature radical initiator / crosslinking agent |
| Control status | Listed as an explosive precursor in China – export licence and end-use declaration required |
How It Works
DCP decomposes on heating to give cumyloxy radicals, which abstract hydrogen from a polymer chain. Two adjacent radicals then combine, forming a direct carbon-carbon bond between chains. The result is a crosslinked network held together by C-C bonds – not by peroxide fragments – which is why peroxide-crosslinked polyethylene keeps its mechanical properties at temperatures where thermoplastic PE would flow.
The decomposition temperature is what makes DCP useful: it is stable enough to survive compounding and extrusion, then decomposes in the vulcanisation step. Too hot during compounding and you scorch the compound; too cool in curing and the crosslink density never develops.
Typical Applications
- Peroxide-crosslinked polyethylene (PEX-a) – wire and cable insulation, hot-water pipe, where the C-C crosslink gives the highest temperature rating of the three PEX types.
- Polypropylene degradation – controlled rheology grades, where radical chain scission narrows the molecular weight distribution and raises melt flow.
- EVA and PE foam – crosslinking before expansion, so the foam cells stay stable.
- Rubber vulcanisation – silicone rubber, EPDM, fluoroelastomers and other saturated rubbers that cannot be sulphur-cured.
- Unsaturated polyester and vinyl ester – high-temperature curing of moulding compounds and composites.
- Grafting reactions – radical grafting of maleic anhydride or silanes onto polyolefins.
Handling and Storage
| Point | Guidance |
|---|---|
| Temperature | Store cool – ideally below 25-30 deg C – and keep away from heat sources, direct sunlight and steam lines |
| Self-accelerating decomposition | Organic peroxides decompose faster as they get hotter. Never allow a drum to sit in a hot container or a closed vehicle |
| Incompatibility | Keep away from acids, bases, reducing agents, metal powders, accelerators and rust – all can trigger rapid decomposition |
| Contamination | Use clean, dedicated scoops and equipment. A trace of cobalt accelerator or an amine can cause violent decomposition |
| Fire response | Water spray from a distance; do not use dry chemical on a decomposing peroxide mass |
| Personal protection | Gloves, eye protection and dust control; the powder is an irritant and a strong oxidiser |
Regulatory Status and Export
Dicumyl peroxide is listed as an explosive precursor (explosive precursor chemical) in China. It is not a narcotic or a drug precursor, and it is a normal industrial chemical with well-established polymer applications – but its export is controlled. In practice this means:
- Export requires a licence issued through the competent authorities; the application needs the end user, the destination country and the intended application.
- An end-use declaration is required – typically a statement from the buyer describing the application (for example crosslinking of cable insulation or pipe compound) and confirming that the material will not be diverted.
- Destination rules apply as well – several markets regulate organic peroxides for transport and for storage, and classify DCP as a strong oxidiser for shipping purposes.
- Domestic sale follows the Chinese explosive-precursor registration rules, which affect record-keeping and buyer verification.
If your company purchases DCP for a compliant industrial use, we can support the documentation: COA, SDS, end-use declaration template and the product description needed for the licence application. Tell us the destination and the application at enquiry stage and we will confirm what is required for that route.
Packaging and Documentation
Supplied in fibre drums or cartons with an inner liner, typically 20-25 kg net. Because the product is temperature sensitive, shipment timing and container placement matter – avoid routes with prolonged high ambient temperatures, and do not store the drum near heat sources on arrival. Each batch ships with a COA covering appearance, peroxide content and active oxygen; SDS is available in English. Licence-related documents are prepared per shipment.
Related reading
- Dicumyl peroxide in XLPE cable insulation and PEX-a pipe
- Silane crosslinking of PE with VTMS (PEX-b)
- Vinyltrimethoxysilane: properties, production and applications
FAQ
What is the CAS number of dicumyl peroxide? CAS 80-43-3.
Why does active oxygen matter? Active oxygen is a direct measure of the peroxide group content. A lot at 5.80% min has the theoretical amount for pure DCP; a lower figure means inert filler or decomposition, and the dosage must be recalculated.
Can you ship DCP without an export licence? No. It is an explosive precursor in China; export requires a licence and an end-use declaration. We will confirm the documentation route for your destination.
How is it different from silane crosslinking? DCP creates direct C-C bonds between chains (PEX-a), giving higher temperature and pressure resistance; silane crosslinking creates Si-O-Si bridges (PEX-b), which needs simpler equipment. See the comparison in the related article.
Contact PolyBlueChem for specifications, samples and export documentation.
