Hexafluoropropylene oxide
Encyclopedia
Hexafluoropropylene oxide (HFPO) is an intermediate used in industrial organofluorine chemistry
; specifically it is a monomer for fluoropolymer
s. This colourless gas is the epoxide
of hexafluoropropylene
, that is fluorinated analog of propylene oxide
, HFPO is produced by DuPont
and 3M
and as a precursor to the lubricant Krytox
and related materials. It is generated by oxidation of perfluoropropylene, e.g. with oxygen as well as other oxidants.
which is decarboxylated with fluorine. The net polymerization reaction can be represented as:
Upon heating above 150 °C, HFPO decomposes to trifluoroacetyl fluoride and difluorocarbene
:
The epoxide of tetrafluoroethylene
is even more unstable with respect to trifluoracetyl fluoride.
In the presence of Lewis acid
s the compound rearranges to hexafluoroacetone
, another important chemical intermediate.
Organofluorine chemistry
Organofluorine chemistry describes the chemistry of organofluorine compounds, organic compounds that contain the carbon–fluorine bond. Organofluorine compounds find diverse applications ranging from oil- and water-repellents to pharmaceuticals, refrigerants and reagents in catalysis...
; specifically it is a monomer for fluoropolymer
Fluoropolymer
A fluoropolymer is a fluorocarbon based polymer with multiple strong carbon–fluorine bonds. It is characterized by a high resistance to solvents, acids, and bases.-History:Fluoropolymers were accidentally discovered in 1938 by Dr. Roy J...
s. This colourless gas is the epoxide
Epoxide
An epoxide is a cyclic ether with three ring atoms. This ring approximately defines an equilateral triangle, which makes it highly strained. The strained ring makes epoxides more reactive than other ethers. Simple epoxides are named from the parent compound ethylene oxide or oxirane, such as in...
of hexafluoropropylene
Hexafluoropropylene
Hexafluoropropylene is a compound with the formula C3F6. It is a fluorocarbon alkene in which all of the hydrogen atoms in propylene are replaced by fluorine atoms. It is used as a chemical intermediate....
, that is fluorinated analog of propylene oxide
Propylene oxide
Propylene oxide is an organic compound with the molecular formula CH3CHCH2O. This colourless volatile liquid is produced on a large scale industrially, its major application being its use for the production of polyether polyols for use in making polyurethane plastics...
, HFPO is produced by DuPont
DuPont
E. I. du Pont de Nemours and Company , commonly referred to as DuPont, is an American chemical company that was founded in July 1802 as a gunpowder mill by Eleuthère Irénée du Pont. DuPont was the world's third largest chemical company based on market capitalization and ninth based on revenue in 2009...
and 3M
3M
3M Company , formerly known as the Minnesota Mining and Manufacturing Company, is an American multinational conglomerate corporation based in Maplewood, Minnesota, United States....
and as a precursor to the lubricant Krytox
Krytox
Krytox is a trademarked name of a family of high-performance synthetic lubricants with a variety of applications. Invented by researchers at DuPont, it is a colourless polymer containing ether functionality...
and related materials. It is generated by oxidation of perfluoropropylene, e.g. with oxygen as well as other oxidants.
Reactivity
Fluoride catalyzes the formation of the perfluorinated polyethers. The initial step entails nucleophilic attack at the middle carbon to give the perfluoropropoxide anion, which in turn attacks another monomer. This process generates a polymer terminated by an acyl fluoride, which is hydrolyzed to the carboxylic acidCarboxylic acid
Carboxylic acids are organic acids characterized by the presence of at least one carboxyl group. The general formula of a carboxylic acid is R-COOH, where R is some monovalent functional group...
which is decarboxylated with fluorine. The net polymerization reaction can be represented as:
- n+2 CF3CFCF2O → CF3CF2CF2O(CF(CF3)CF2O)nCF2CF3 + CO
Upon heating above 150 °C, HFPO decomposes to trifluoroacetyl fluoride and difluorocarbene
Difluorocarbene
Difluorocarbene is the chemical compound with formula CF2. It has a short half-life, 0.5 and 20 msec, in solution and in the gas phase, respectively...
:
- CF3CFCF2O → CF3C(O)F + CF2
The epoxide of tetrafluoroethylene
Tetrafluoroethylene
Tetrafluoroethylene is a chemical compound with the formula C2F4. It is the simplest alkene fluorocarbon. This gaseous species is used primarily in the industrial preparation of polymers.-Properties:...
is even more unstable with respect to trifluoracetyl fluoride.
In the presence of Lewis acid
Lewis acid
]The term Lewis acid refers to a definition of acid published by Gilbert N. Lewis in 1923, specifically: An acid substance is one which can employ a lone pair from another molecule in completing the stable group of one of its own atoms. Thus, H+ is a Lewis acid, since it can accept a lone pair,...
s the compound rearranges to hexafluoroacetone
Hexafluoroacetone
Hexafluoroacetone is a chemical compound with the formula CF3-CO-CF3. It is structurally similar to acetone, however its reactivity is markedly different. It comes in the form of a colourless, hygroscopic, nonflammable, highly reactive gas characterized by a musty odour...
, another important chemical intermediate.