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As one of the world's leading suppliers of organic peroxides, Arkema manufactures and markets azo initiators, diacyl peroxides, dialkyl peroxides, hydroperoxides, ketone peroxides, peroxydicarbonates, peroxyesters, and peroxyketals marketed under the brand name Luperox® organic peroxides.
Organic peroxides refer to a family of molecules containing at least two oxygen atoms, single-bonded together. The general structure is:
This kind of bond has the property of being quite easy to break under the action of heating (homolitic scission), leaving on each oxygen one unpaired electron, called a free radical.
Free radicals promote certain chemical reactions such as:
- Polymerization of one or more monomers
- Control rheology of Polypropylene
- Curing of thermosetting resins
- Crosslinking of elastomers and polyethylene
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Under the action of heat (homolitic scission)
At room temperature, in the presence of an activator like metallic salts compounds or an amine (redox systems).
proposed mechanism of reaction with cobalt activator
Typical monomers that can be polymerized by organic peroxides are:
- Ethylene
- Styrene
- Vinyl Chloride
- (Meth)acrylics
- Acrylonitrile (SAN/ABS)
For elastomers and polyethylene crosslinking, the main fields of applications are:
- wire and cable insulation (e.g. made from PE, EPM, EPDM)
- profiles continuously crosslinked in salt baths or by steam (mainly EPDM)
- pipes and hoses for automobile radiators (EPDM, NBR)
- pipes for drinkable water (LDPE or HDPE)
- pipes for under-floor heating (HDPE)
- shoe soles (foamed and crosslinked EVA, PE, SBR, etc.)
- roller coverings (EPDM, NBR, Q)
- rotational mouldings (PE, EVA)
- medical supplies (e.g. tubes Q)
- foamed articles with closed-cell structure (e.g. made from PE, EVA, CM)
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