Perfluorinated compounds
Encyclopedia
A perfluorinated compound (PFC) is an organofluorine compound with all hydrogen
s replaced by fluorine
on a carbon
chain—but the molecule
also contains at least one different atom
or functional group
. Thus, PFCs have properties similar to fluorocarbon
s (a wholly carbon and fluorine containing compound) as they are fluorocarbon derivatives. They have unique properties to make materials stain, oil, and water resistant, and are widely used in diverse applications. PFCs persist in the environment as persistent organic pollutant
s, but unlike PCB
s, they are not known to degrade by any natural processes due to the strength of the carbon–fluorine bond
.
Other PFCs include:
PFOS and POSF are included within Annex B of the Stockholm Convention on Persistent Organic Pollutants
.
Polyfluorinated compounds, such as fluorotelomer
s, can serve as precursors that degrade to form perfluorinated carboxylic acid
s, such as PFOA and PFNA.
Hydrogen
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
s replaced by fluorine
Fluorine
Fluorine is the chemical element with atomic number 9, represented by the symbol F. It is the lightest element of the halogen column of the periodic table and has a single stable isotope, fluorine-19. At standard pressure and temperature, fluorine is a pale yellow gas composed of diatomic...
on a carbon
Carbon
Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...
chain—but the molecule
Molecule
A molecule is an electrically neutral group of at least two atoms held together by covalent chemical bonds. Molecules are distinguished from ions by their electrical charge...
also contains at least one different atom
Atom
The atom is a basic unit of matter that consists of a dense central nucleus surrounded by a cloud of negatively charged electrons. The atomic nucleus contains a mix of positively charged protons and electrically neutral neutrons...
or functional group
Functional group
In organic chemistry, functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. The same functional group will undergo the same or similar chemical reaction regardless of the size of the molecule it is a part of...
. Thus, PFCs have properties similar to fluorocarbon
Fluorocarbon
Fluorocarbons, sometimes referred to as perfluorocarbons or PFCs, are organofluorine compounds that contain only carbon and fluorine bonded together in strong carbon–fluorine bonds. Fluoroalkanes that contain only single bonds are more chemically and thermally stable than alkanes...
s (a wholly carbon and fluorine containing compound) as they are fluorocarbon derivatives. They have unique properties to make materials stain, oil, and water resistant, and are widely used in diverse applications. PFCs persist in the environment as persistent organic pollutant
Persistent organic pollutant
thumb|right|275px|State parties to the Stockholm Convention on Persistent Organic PollutantsPersistent organic pollutants are organic compounds that are resistant to environmental degradation through chemical, biological, and photolytic processes...
s, but unlike PCB
Polychlorinated biphenyl
Polychlorinated biphenyls are a class of organic compounds with 2 to 10 chlorine atoms attached to biphenyl, which is a molecule composed of two benzene rings. The chemical formula for PCBs is C12H10-xClx...
s, they are not known to degrade by any natural processes due to the strength of the carbon–fluorine bond
Carbon–fluorine bond
The carbon–fluorine bond is a bond between carbon and fluorine that is a component of all organofluorine compounds. It is the strongest single bond in organic chemistry—and relatively short—due to its partial ionic character. The bond also strengthens and shortens as more fluorines are...
.
Examples
There are many PFCs, but the two most studied compounds are:- PFOA or perfluorooctanoic acidPerfluorooctanoic acidPerfluorooctanoic acid , also known as C8 and perfluorooctanoate, is a synthetic, stable perfluorinated carboxylic acid and fluorosurfactant. One industrial application is as a surfactant in the emulsion polymerization of fluoropolymers. It has been used in the manufacture of such prominent...
, used to make fluoropolymerFluoropolymerA 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 such as Teflon, among other applications. - PFOS or perfluorooctanesulfonic acid, used in the semiconductor industry, 3M3M3M Company , formerly known as the Minnesota Mining and Manufacturing Company, is an American multinational conglomerate corporation based in Maplewood, Minnesota, United States....
's former ScotchgardScotchgardScotchgard is a 3M brand of products used to protect fabric, furniture, and carpets from stains.The original formula for Scotchgard was discovered accidentally in 1952 by 3M chemists Patsy Sherman and Samuel Smith...
formulation, and 3M's former fire-fighting foam mixture.
Other PFCs include:
- PFNA or perfluorononanoic acidPerfluorononanoic acidPerfluorononanoic acid, or PFNA, is a synthetic perfluorinated carboxylic acid and fluorosurfactant that is also an environmental contaminant found in people and wildlife along with PFOS and PFOA.-Chemistry and properties:...
, used as surfactantSurfactantSurfactants are compounds that lower the surface tension of a liquid, the interfacial tension between two liquids, or that between a liquid and a solid...
in the emulsion polymerizationEmulsion polymerizationEmulsion polymerization is a type of radical polymerization that usually starts with an emulsion incorporating water, monomer, and surfactant. The most common type of emulsion polymerization is an oil-in-water emulsion, in which droplets of monomer are emulsified in a continuous phase of water...
of fluoropolymers, like PFOA. - PFBS or perfluorobutanesulfonic acidPerfluorobutanesulfonic acidPerfluorobutanesulfonic acid is a chemical compound with a four carbon fluorocarbon chain and a sulfonic acid functional group. As an anion it functions as a stable fluorosurfactant because of the strength of carbon–fluorine bonds....
, used as a replacement for PFOS in 3M's reformulated Scotchgard. - POSF or perfluorooctanesulfonyl fluoridePerfluorooctanesulfonyl fluoridePerfluorooctanesulfonyl fluoride is a synthetic perfluorinated compound with a sulfonyl fluoride functional group. It is used to make perfluorooctanesulfonic acid and PFOS-based compounds...
, used to make PFOS-based compounds. - PFOSA or perfluorooctanesulfonamidePerfluorooctanesulfonamidePerfluorooctanesulfonamide is a synthetic organofluorine compound. It is a fluorocarbon derivative, or perfluorinated compound, with eight carbons and a terminal sulfonamide functional group. PFOSA was an ingredient in 3M's former Scotchgard formulation and the compound was used to repel grease...
, formerly used in 3M's Scotchgard formulation. - FC-75FC-75FC-75 is a fluorocarbon derivative of tetrahydrofuran with the chemical formula C8F16O. It is practically insoluble in water.It is one of the 3M Fluorinert fluids. It is used as an inert coolant fluid in electronics and other applications, and as a solvent. FC-75 can be synthesized by the same...
, a 3M FluorinertFluorinertFluorinert is the trademarked brand name for the line of electronics coolant liquids sold commercially by 3M. It is an electrically insulating, stable fluorocarbon-based fluid which is used in various cooling applications. It is mainly used for cooling electronics...
liquid and perfluorinated cyclic etherEtherEthers are a class of organic compounds that contain an ether group — an oxygen atom connected to two alkyl or aryl groups — of general formula R–O–R'. A typical example is the solvent and anesthetic diethyl ether, commonly referred to simply as "ether"...
.
PFOS and POSF are included within Annex B of the Stockholm Convention on Persistent Organic Pollutants
Stockholm Convention on Persistent Organic Pollutants
Stockholm Convention on Persistent Organic Pollutants is an international environmental treaty, signed in 2001 and effective from May 2004, that aims to eliminate or restrict the production and use of persistent organic pollutants .- History :...
.
Polyfluorinated compounds, such as fluorotelomer
Fluorotelomer
Fluorotelomers are fluorocarbon-based oligomers, or telomers, synthesized by telomerization. Some fluorotelomers and fluorotelomer-based compounds are a source of environmentally persistent perfluorinated carboxylic acids such as PFOA and PFNA, while others are under extended...
s, can serve as precursors that degrade to form perfluorinated carboxylic acid
Perfluorinated carboxylic acid
Perfluorinated carboxylic acids , or perfluorocarboxylates are fully fluorinated organofluorine compounds—or perfluorinated compounds—with carboxylic acid or carboxylate functional groups. PFCAs are fluorocarbon derivatives...
s, such as PFOA and PFNA.