Dicumyl peroxide

Structural formula
General
Surname	Dicumyl peroxide
other names	DCP DCUP 8,8'-dicumenyl peroxide Bis (1-methyl-1-phenylethyl) peroxide Bis (α, α-dimethylbenzyl) peroxide
Molecular formula	C 18 H 22 O 2
Brief description	white solid
External identifiers / databases
CAS number 80-43-3 EC number 201-279-3 ECHA InfoCard 100.001.164 PubChem 6641 Wikidata Q1210367
properties
Molar mass	270.37 g mol −1
Physical state	firmly
density	1.02 g cm −3
Melting point	37-40 ° C , 39 ° C
boiling point	> 70 ° C (decomposition)
solubility	practically insoluble in water (0.4–2 mg · l −1 )
safety instructions
GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary Caution H and P phrases H: 242-315-319-411 P: 210-273-280-302 + 352-305 + 351 + 338
Toxicological data	4100 mg kg −1 ( LD 50 ,  rat ,  oral )
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Dicumyl peroxide (systematic name bis (1-methyl-1-phenylethyl) peroxide ) is an organic-chemical , aromatic compound from the group of peroxides . The name is derived from the cumyl residue , which is connected to a second, similar residue via a peroxide bridge.

Presentation and extraction

Dicumyl peroxide is synthesized by reacting 2-phenyl-2-propanol with the hydrogen peroxide / urea adduct at 35 ° C in the presence of a mineral acid . In a further synthesis, 2-phenyl-2-propanol is reacted with cumene hydroperoxide .

properties

Dicumyl peroxide is a white to yellowish powder with a characteristic odor that is practically insoluble in water (0.4–2 mg / l), but dissolves well in alcohols, esters and aromatic hydrocarbons. The solid crystallizes in a rhombic crystal lattice. Thermal decomposition begins above 70 ° C.

The peroxide is fire-promoting and should never come into contact with flammable substances.

use

It is used as a crosslinking agent for polyolefins and elastomers, and for curing unsaturated polyester resins . Many plastics , such as polyethylene , are post-treated with dicumyl peroxide in order to improve material properties such as elasticity, oil and acid resistance through greater crosslinking of the polymer chains.

Risk assessment

In 2015, dicumyl peroxide was included in the EU's ongoing action plan ( CoRAP ) in accordance with Regulation (EC) No. 1907/2006 (REACH) as part of substance evaluation . The effects of the substance on human health and the environment are re-evaluated and, if necessary, follow-up measures are initiated. The reasons for the intake of dicumyl peroxide were concerns about consumer use , environmental exposure, exposure of workers , high (aggregated) tonnage, high risk characterization ratio (RCR) and widespread use as well as the hazards arising from a possible assignment to the group of PBT / vPvB substances. The re-evaluation has been running since 2015 and is carried out by Norway . In order to be able to reach a final assessment, further information was requested.

Individual evidence

1. ↑ ^{a b c d e} data sheet bis (α, α-dimethylbenzyl) peroxide (PDF) from Merck , accessed on March 24, 2011.
2. ↑ ^{a b c d e} Entry on dicumyl peroxide. In: Römpp Online . Georg Thieme Verlag, accessed on January 27, 2017.
3. ↑ ^{a b c} Entry on dicumyl peroxide in the GESTIS substance database of the IFA , accessed on February 1, 2016(JavaScript required) .
4. ↑ Entry on bis (α, α-dimethylbenzyl) peroxide in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
5. ↑ ^{a b} H. Klenk; PH Goetz; R. Siegmeier; W. Mayr: Organic Peroxy Compounds , in: Ullmanns Enzyklopädie der Technischen Chemie , Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 2012; doi : 10.1002 / 14356007.a19_199 .
6. ↑ Kosnikov, A.Yu .; Antonovskii, VL; Turovskii, NA; Lindeman, SV; Timofeeva, TV: in Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation) 37 (1988) 674-678.
7. ↑ Community rolling action plan ( CoRAP ) of the European Chemicals Agency (ECHA): bis (α, α-dimethylbenzyl) peroxide , accessed on March 26, 2019.