Difference between revisions of "Peroxide forming chemicals"
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==Properties== | ==Properties== | ||
| − | Organic peroxides are solid compounds, very sensitive to mechanical stress | + | Organic peroxides are liquid or solid compounds, often very sensitive to mechanical stress such as friction and shock, as well as heat. They are non-volatile, and explode if heated to high temperature.<ref>http://ccc.chem.pitt.edu/wipf/Web/16340.pdf</ref><ref name="hwperox">R. Criegee in ''Houben-Weyl, Methoden der organischen Chemie, Sauerstoffverbindungen III, Band VIII, "Herstellung und Umwandlung von Peroxyden"'', Georg-Thieme, Stuttgart '''1952''', p. 73-74.</ref> |
| + | |||
| + | Most commonly solvents contain mainly hydroperoxide species, but their decomposition products can also be present. [[Diisopropyl ether]] for example may contain dimeric or trimeric [[acetone peroxide]].<ref>A. Rieche, K. Koch, ''Ber. dtsch. Chem. Ges. A/B'', '''75''', 1016-1028 (1942). [https://doi.org/10.1002/cber.19420750815 https://doi.org/10.1002/cber.19420750815]</ref> | ||
==Peroxide detection== | ==Peroxide detection== | ||
| − | + | There are numerous methods reported for peroxide detection. Almost all organic peroxides can be detected by using a solution of [[potassium iodide]] in [[water]] or [[acetic acid]]. If any peroxides are present in the liquid, the iodide solution will turn yellow at low levels of peroxides, and brown to purple-ish at high concentrations.<ref name="hwperox" /> Starch may be added to further increase sensitivity.<ref name="illutest">''Test auf Peroxide in Diethylether'', [https://illumina-chemie.de/viewtopic.php?f=22&t=4541 https://illumina-chemie.de/viewtopic.php?f=22&t=4541]</ref> This test does not work for acetone peroxide, for which titanium sulfate in 50% [[sulfuric acid]] is used: a yellow to orange color indicates the presence of peroxides.<ref name="hwperox" /> | |
| + | |||
| + | Vandate(V) and sulfuric acid reagent can also be used for non-cyclic ethers. An orange- to redbrown color indicates the presence of peroxides.<ref name="illutest" /> Another method involves the use of hemin chloride and luminol in [[sodium carbonate]] solution. Peroxide containing solvents show blue chemiluminescence.<ref name="illutest" /> | ||
==Handling== | ==Handling== | ||
Revision as of 17:36, 29 July 2023
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Peroxide forming chemicals are a group of chemical compounds capable of forming very sensitive peroxides if exposed to atmospheric oxygen. While most are organic, potassium metal is known to form the unstable potassium peroxide (K2O2) in contact with air.
Chemicals that form peroxides when treated with hydrogen peroxide or some other form of peroxide are not included in this group, as these compounds require an already existing peroxide and do not form such peroxides in contact with atmospheric oxygen. Like wise, chemicals that form peroxides at high temperatures (like barium oxide) or other extreme/unique conditions are also not included here.
Contents
General
Chemical compounds, such as ethers, secondary alcohols or certain unsaturated hydrocarbons will produce unstable peroxides upon contact with air, process accelerated by light or heat, over the course of months or years. The autoxidation of said compounds produces both normal peroxides, as well as hydroperoxides.[1][2] There are 2 main categories of peroxide forming chemicals, as well as two additional more.[3][4]
Ethers like dimethyl ether, methyl tert-butyl ether and tertiary ethers do not form explosive peroxides in contact with air, due to the lack of α hydrogens.
Categories
Group A
Compounds that form explosive levels of peroxides without concentration, and can explode without warning at high enough concentrations.
- Butadiene
- Chloroprene
- Divinyl acetylene
- Diisopropyl ether
- Potassium
- Potassium amide
- Sodium amide
- Tetrafluoroethylene
- Vinylidene chloride
Group B
Compounds that form explosive levels of peroxides during concentration, and tend to explode when dry. Safe when wet.
- 1-Phenylethanol
- 2-Cyclohexen-1-ol
- 2-Hexanol
- 2-Pentanol
- 2-Phenylethanol
- 3-Methyl-1-butanol
- 4-Heptanol
- 4-Methyl-2-pentanol
- 4-Penten-1-ol
- 1,4-Dioxane
- Acetal
- Acetaldehyde
- Benzyl alcohol
- Chlorofluoroethylene
- Cumene
- Cyclohexene
- Cyclopentene
- Decalin
- Diacetylene
- Dicyclopentadiene
- Diethyl ether
- Diglyme
- Dimethoxyethane
- Furan
- Isopropanol
- Methyl-isobutyl ketone
- Propyne
- sec-Butanol
- Tetrahydrofuran
- Tetralin
- Vinyl ethers
- Other secondary alcohols
Group C
Compounds which are hazardous due to peroxide initiation of autopolymerization.
- Acrylic acid
- Acrylonitrile
- Butadienea
- Chlorobutadiene
- Chloroprenea
- Chlorotrifluoroethylene
- Methyl methacrylateb
- Styrene
- Tetrafluoroethylene
- Vinyl acetate
- Vinyl acetylene
- Vinyl chloride
- Vinyl pyridine
- Vinyldiene chloride
Group D
Chemicals that may form peroxides but cannot be classified in the previous categories
- 1-Ethoxy-2-propyne
- 1-Ethoxynaphthalene
- 1-Octene
- 1-Pentene
- 1-(2-Chloroethoxy)-2-phenoxyethane
- 1-(2-Ethoxyethoxy)-ethyl acetate
- 1,1-Dimethoxyethane
- 1,1,2,3-Tetrachloro-1,3-butadiene
- 1,2-Bis(2-chloroethoxy)-ethane
- 1,2-Dibenzyloxyethane
- 1,2-Dichloroethyl ethyl ether
- 1,2-Diethoxyethane
- 1,2-Epoxy-3-isopropoxypropane
- 1,2-Epoxy-3-phenoxypropane
- 1,3-Butadiyne
- 1,3-Dioxepane
- 1,3,3-Trimethoxy-propene
- 1,5-p-Methadiene
- 2-Bromomethyl ethyl ether
- 2-Chlorobutadiene
- 2-Ethoxyethyl acetate
- (2-Ethoxyethyl)-o-benzoyl benzoate
- 2-Ethylbutanol
- 2-Ethylhexanal
- 2-Methoxy-ethanol
- 2-Methyltetra-hydrofuran
- 2,2-Diethoxypropane
- 2,4-Dichlorophenetole
- 2,4-Dinitrophenetole
- 2,4,5-Tri-chlorophenoxyacetate
- 2,5-Hexadiyn-1-ol
- 3-Bromopropyl phenyl ether
- 3-Ethoxyopropionitrile
- 2-Ethylacrylaldehyde oxime
- 3-Methoxy-1-butyl acetate
- 3,3-Dimethoxypropene
- 4-Methyl-2-pentanone
- 4-Vinyl cyclohexene
- 4,5-Hexadien-2-yn-1-ol
- Acrolein
- Allyl ether
- Allyl ethyl ether
- Allyl phenyl ether
- Benzyl 1-napthyl ether
- Benzyl ether
- Benzyl ethyl ether
- Benzyl methyl ether
- Benzyl n-butyl ether
- Bis(2-chloroethyl) ether
- Bis(2-ethoxyethyl) adipate
- Bis(2-ethoxyethyl) ether
- Bis(2-ethoxyethyl) phthalate
- Bis(2-(methoxyethoxy)-ethyl) ether
- Bis(2-methoxyethyl) carbonate
- Bis(2-methoxyethyl) ether
- Bis(2-methoxyethyl) phthalate
- Bis(2-methoxymethyl) adipate
- Bis(2-n-butoxyethyl) phthalate
- Bis(2-phenoxyethyl) ether
- Bis(4-chlorobutyl) ether
- Bis(chloromethyl) ether
- Buten-3-yne
- Chloroacetaldehyde diethylacetal
- Chloroethylene
- Chloromethyl methyl ether
- Cyclooctene
- Cyclopropyl methyl ether
- Di(1-propynyl)ether
- Di(2-propynyl)ether
- Di-n-propoxymethane
- Diallyl ether
- Diethoxymethane
- Diethyl acetal
- Diethyl ethoxymethylene-malonate
- Diethyl fumarate
- Diethyketene
- Dimethoxymethane
- Dimethylketene
- Ethyl vinyl ether
- Ethyl β-ethoxy-propionate
- Furan
- Isoamyl benzyl ether
- Isoamyl ether
- Isobutyl vinyl ether
- Isophorone
- Limonene
- m,o,p-Diethoxybenzene
- m-Nitro-phenetole
- Methonxy-1,3,5,7-cyclooctatetraene
- Methyl p-(n-amyloxy)benzoate
- n-Amyl ether
- n-Butyl phenyl ether
- n-Butyl vinyl ether
- n-Hexyl ether
- n-Methylphenetole
- n-Propyl ether
- n-Propyl isopropyl ether
- o-Bromophenetole
- o-Chlorophenetol
- o,p-Ethoxyphenyl isocyanate
- o,p-Iodophenetole
- Oxybis(2-ethyl acetate)
- Oxybis(2-ethyl benzoate)
- p-(n-Amyloxy)benzoyl chloride
- p-Bromophenetole
- p-Chlorophenetole
- p-Di-n-butoxybenzene
- p-Dibenzyloxybenzene
- p-Ethoxyacetho-phenone
- p-Phenylphenetone
- Phenoxyacetyl chloride
- Phenyl o-propyl ether
- Sodium 8,11,14-eicosa-tetraenoate
- Sodium ethoxyacetylide
- tert-Butyl ethyl ether
- Tetrahydropyran
- Triethylene glycol diacetate
- Triethylene glycol dipropionate
- Vinylene carbonate
- Vinylidene chloride
- α-Phenoxy-propionyl chloride
- β-Bromophenetole
- β-Chlorophenetole
- β-Isopropoxy-propionitrile
- β-Methoxy-propionitrile
- β,β-Oxydi-propionitrile
Properties
Organic peroxides are liquid or solid compounds, often very sensitive to mechanical stress such as friction and shock, as well as heat. They are non-volatile, and explode if heated to high temperature.[5][6]
Most commonly solvents contain mainly hydroperoxide species, but their decomposition products can also be present. Diisopropyl ether for example may contain dimeric or trimeric acetone peroxide.[7]
Peroxide detection
There are numerous methods reported for peroxide detection. Almost all organic peroxides can be detected by using a solution of potassium iodide in water or acetic acid. If any peroxides are present in the liquid, the iodide solution will turn yellow at low levels of peroxides, and brown to purple-ish at high concentrations.[6] Starch may be added to further increase sensitivity.[8] This test does not work for acetone peroxide, for which titanium sulfate in 50% sulfuric acid is used: a yellow to orange color indicates the presence of peroxides.[6]
Vandate(V) and sulfuric acid reagent can also be used for non-cyclic ethers. An orange- to redbrown color indicates the presence of peroxides.[8] Another method involves the use of hemin chloride and luminol in sodium carbonate solution. Peroxide containing solvents show blue chemiluminescence.[8]
Handling
Safety
Compounds prone to forming dangerous peroxides should not be distilled to dryness, as the explosive peroxides will explode when dry. A good tip would be to add some high boiling solvent, like glycerol.
Storage
Compounds known to form peroxides should be kept in sealed bottles. BHT should be added as anti-oxidant, though a sheet of fresh metal, like copper can also be used. Sodium hydroxide can be added to precipitate any peroxides formed.
Disposal
Sensitive peroxides can be neutralized using a reducing agent, like sodium sulfite or ferrous sulfate. For ethers, metallic sodium can also be used, along with stirring or refluxing for better performance.
DO NOT ATTEMPT TO OPEN VERY OLD BOTTLES THAT HAVE PEROXIDES ON THE CAP!
See also
References
- ↑ http://www.ilpi.com/msds/ref/peroxide.html
- ↑ http://www.sigmaaldrich.com/chemistry/solvents/learning-center/peroxide-formation.html
- ↑ http://ccc.chem.pitt.edu/wipf/Web/16340.pdf
- ↑ http://www.baylor.edu/ehs/doc.php/203991.pdf
- ↑ http://ccc.chem.pitt.edu/wipf/Web/16340.pdf
- ↑ 6.0 6.1 6.2 R. Criegee in Houben-Weyl, Methoden der organischen Chemie, Sauerstoffverbindungen III, Band VIII, "Herstellung und Umwandlung von Peroxyden", Georg-Thieme, Stuttgart 1952, p. 73-74.
- ↑ A. Rieche, K. Koch, Ber. dtsch. Chem. Ges. A/B, 75, 1016-1028 (1942). https://doi.org/10.1002/cber.19420750815
- ↑ 8.0 8.1 8.2 Test auf Peroxide in Diethylether, https://illumina-chemie.de/viewtopic.php?f=22&t=4541
