Hexafluoropropylene oxide (HFPO) is an intermediate used in industrial

organofluorine chemistry Organofluorine chemistry describes the chemistry of the organofluorines, organic compounds that contain the carbon–fluorine bond. Organofluorine compounds find diverse applications ranging from Lipophobicity, oil and hydrophobe, water repellents ...

; specifically it is a monomer for

fluoropolymer A fluoropolymer is a fluorocarbon-based polymer with multiple carbon–fluorine bonds. It is characterized by a high resistance to solvents, acids, and bases. The best known fluoropolymer is polytetrafluoroethylene under the brand name "Teflon ...

s. This colourless gas is the

epoxide In organic chemistry, an epoxide is a cyclic ether () with a three-atom ring. This ring approximates an equilateral triangle, which makes it strained, and hence highly reactive, more so than other ethers. They are produced on a large scale for ...

hexafluoropropylene Hexafluoropropylene is the fluoroalkene with the formula CF3CF=CF2. It is the perfluorocarbon counterpart to the hydrocarbon propylene. It is mainly used to produce copolymers with tetrafluoroethylene. Hexafluoropropylene is used as a chemical i ...

, that is fluorinated analog of

propylene oxide Propylene oxide is an acutely toxic and carcinogenic organic compound with the molecular formula CH3CHCH2O. This colourless volatile liquid with an odour similar to ether, is produced on a large scale industrially. Its major application is its us ...

, HFPO is produced by

DuPont DuPont de Nemours, Inc., commonly shortened to DuPont, is an American multinational chemical company first formed in 1802 by French-American chemist and industrialist Éleuthère Irénée du Pont de Nemours. The company played a major role in ...

and 3M and as a precursor to the lubricant

Krytox Krytox is a registered trademark of The Chemours Company. It refers to a group of colourless synthetic lubricants (oils and greases) with a variety of applications. Invented by researchers at DuPont, Krytox oils are fluorocarbon ether polymers o ...

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 such as Krytox. The initial step entails

nucleophilic attack In chemistry, a nucleophile is a chemical species that forms bonds by donating an electron pair. All molecules and ions with a free pair of electrons or at least one pi bond can act as nucleophiles. Because nucleophiles donate electrons, they are ...

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 In organic chemistry, an acyl halide (also known as an acid halide) is a chemical compound derived from an oxoacid by replacing a hydroxyl group () with a halide group (, where X is a halogen). If the acid is a carboxylic acid (), the compound c ...

, which is hydrolyzed to the

carboxylic acid In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group () attached to an R-group. The general formula of a carboxylic acid is or , with R referring to the alkyl, alkenyl, aryl, or other group. Carboxylic ...

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 is the chemical compound with formula CF2. It has a short half-life, 0.5 and 20 ms, in solution and in the gas phase, respectively.Douglas A Jean Osteraas "Difluorocarbene Modification of Polymer and Fiber Surfaces," ''Journal ...

: :CF₃CFCF₂O → CF₃C(O)F + CF₂ The epoxide of

tetrafluoroethylene Tetrafluoroethylene (TFE) is a fluorocarbon with the chemical formula C2 F4. It is the simplest perfluorinated alkene. This gaseous species is used primarily in the industrial preparation of fluoropolymers. Properties Tetrafluoroethylene is a ...

is even more unstable with respect to trifluoracetyl fluoride. In the presence of

Lewis acid A Lewis acid (named for the American physical chemist Gilbert N. Lewis) is a chemical species that contains an empty orbital which is capable of accepting an electron pair from a Lewis base to form a Lewis adduct. A Lewis base, then, is any sp ...

s the compound rearranges to

hexafluoroacetone Hexafluoroacetone (HFA) is a chemical compound with the formula (CF3)2CO. It is structurally similar to acetone; however, its reactivity is markedly different. It a colourless, hygroscopic, nonflammable, highly reactive gas characterized by a must ...

, another important chemical intermediate. Methanolysis affords methyl trifluoropyruvate, a reagent useful in organic synthesis:{{cite encyclopedia, title=Methyltrifluoropyruvate, authors=Ruth Figueroa, Richard P. Hsung, Gang Li, Jin Haek Yang, year=2007, doi=10.1002/047084289X.rn00769, publisher=John Wiley & Sons, encyclopedia=e-EROS Encyclopedia of Reagents for Organic Synthesis, isbn=978-0471936237 :CF₃CFCF₂O + 2 MeOH → CF₃C(O)CO₂Me + MeF + 2 HF

References

External links

HFPO data sheet from DuPontDyneon HFPO from 3M
Trifluoromethyl compounds Epoxides Perfluorinated compounds Monomers