Chemistry:Methyl ethyl ketone peroxide

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Methyl ethyl ketone peroxide
MEK peroxide linear dimer.png
Names
Preferred IUPAC name
2,2′-Peroxydi(butane-2-peroxol)
Other names
2-[(2-Hydroperoxybutan-2-yl)peroxy]butane-2-peroxol
2-Hydroperoxy-2-[(2-hydroperoxybutan-2-yl)peroxy]butane
Ketonox
Mepox
Thermacure
Identifiers
3D model (JSmol)
1759757
ChemSpider
EC Number
  • 215-661-2
MeSH Methyl+ethyl+ketone+peroxide
UNII
UN number 3105
Properties
C8H18O6
Molar mass 210.226 g·mol−1
Appearance Colorless liquid
Density 1.170 g cm−3
Boiling point Decomposition beyond 80 °C (176 °F) [2]
Soluble[1]
Explosive data
Shock sensitivity High
Detonation velocity 5200 m/s
RE factor 0.9
Hazards
Main hazards Explosive, Toxic
GHS pictograms GHS01: Explosive GHS07: Harmful GHS08: Health hazard
GHS Signal word DANGER
H202, H205, H241, H300, H315, H318, H335
P102, P220, P243, P250, P261, P264, P280, P283, P370+380, P372, P404
NFPA 704 (fire diamond)
Flammability code 2: Must be moderately heated or exposed to relatively high ambient temperature before ignition can occur. Flash point between 38 and 93 °C (100 and 200 °F). E.g. diesel fuelHealth code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformReactivity code 4: Readily capable of detonation or explosive decomposition at normal temperatures and pressures. E.g. nitroglycerinSpecial hazards (white): no codeNFPA 704 four-colored diamond
2
2
4
Flash point 75 °C (167 °F; 348 K)[2]
NIOSH (US health exposure limits):
PEL (Permissible)
none[1]
REL (Recommended)
C 0.2 ppm (1.5 mg/m3)[1]
IDLH (Immediate danger)
N.D.[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references
Tracking categories (test):

Methyl ethyl ketone peroxide (MEKP) is an organic peroxide with the formula [(CH3)(C2H5)C(O2H)]2O2. MEKP is a colorless oily liquid. It is widely used in vulcanization (crosslinking) of polymers.[3]

It is derived from the reaction of methyl ethyl ketone and hydrogen peroxide under acidic conditions. Several products result from this reaction including a cyclic dimer.[4] The linear dimer, the topic of this article, is the most prevalent.[5] and this is the form that is typically quoted in the commercially available material.[6]

Solutions of 30 to 40% MEKP are used in industry and by hobbyists as catalyst to initiate the crosslinking of unsaturated polyester resins used in fiberglass, and casting. For this application, MEKP often is dissolved in a phlegmatizer such as dimethyl phthalate, cyclohexane peroxide,[clarification needed] or diallyl phthalate (de) to reduce sensitivity to shock. Benzoyl peroxide can be used for the same purpose.[citation needed]

Safety

Whereas acetone peroxide is a white powder at STP, MEKP is slightly less sensitive to shock and temperature, and more stable in storage.

MEKP is a severe skin irritant and can cause progressive corrosive damage or blindness.

The volatile decomposition products of MEKP can contribute to the formation of vapor-phase explosions. Ensuring safe storage is important, and the maximum storage temperature should be limited to below 30 °C.[7]

Notes

  1. 1.0 1.1 1.2 1.3 NIOSH Pocket Guide to Chemical Hazards. "#0416". National Institute for Occupational Safety and Health (NIOSH). https://www.cdc.gov/niosh/npg/npgd0416.html. 
  2. 2.0 2.1 Record of 2-Butanone peroxide in the GESTIS Substance Database of the Institute for Occupational Safety and Health, accessed on 10 March 2013.
  3. Klenk, Herbert; Götz, Peter H.; Siegmeier, Rainer; Mayr, Wilfried (2000). "Ullmann's Encyclopedia of Industrial Chemistry". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a19_199. 
  4. Pastureau, P. (1907). "Le superoxyde de la méthyléthylcétone". Comptes Rendus 144 (2): 90–93. https://books.google.com/books?id=zloDAAAAYAAJ&pg=PA90. 
  5. Milas, N. A.; Golubović, A. (1959). "Studies in Organic Peroxides. XXV. Preparation, Separation and Identification of Peroxides Derived from Methyl Ethyl Ketone and Hydrogen Peroxide". Journal of the American Chemical Society 81 (21): 5824–5826. doi:10.1021/ja01530a068. 
  6. "2-Butanone peroxide". Sigma-Aldrich. http://www.sigmaaldrich.com/catalog/Lookup.do?N5=All&N3=mode+matchpartialmax&N4=2-Butanone+peroxide&D7=0&D10=2-Butanone+peroxide&N1=S_ID&ST=RS&N25=0&F=PR. Retrieved 2011-12-05. 
  7. "Methyl Ethyl Ketone Peroxide (MEKP): Production And Uses" (in en-US). 2023-05-19. https://chemcess.com/methyl-ethyl-ketone-peroxide-mekp/. 

External links