Polysulfone
Encyclopedia
Polysulfone describes a family of thermoplastic
polymers. These polymers are known for their toughness and stability at high temperatures. They contain the subunit aryl
-SO2-aryl, the defining feature of which is the sulfone
group. Polysulfones were introduced in 1965 by Union Carbide
. Due to the high cost of raw materials and processing, polysulfones are used in specialty applications and often are a superior replacement for polycarbonate
s.
and bis(4-chlorophenyl)sulfone, forming a polyether by elimination of sodium chloride
:
The diphenol is typically bisphenol-A or, 1,4-dihydroxybenzene
. Such step polymerizations require highly pure monomer to ensure high molecular weight products.
Polysulfone is highly resistant to mineral acid
s, alkali
, and electrolyte
s, in pH
ranging from 2 to 13. It is resistant to oxidizing agents, therefore it can be cleaned by bleach
es. It is also resistant to surfactant
s and hydrocarbon
oil
s. It is not resistant to low-polar organic solvents (e.g. ketone
s and chlorinated hydrocarbons), and aromatic hydrocarbon
s. Mechanically, polysulfone has high compaction resistance, recommending its use under high pressures. It is also stable in aqueous acids and bases and many non-polar solvents; however it is soluble in dichloromethane and methylpyrrolidone
.
Polyethersulfone (PES) is a similar polymer with low protein retention.
, without compromising its strength that usually results from addition of flame retardants. Its high hydrolysis stability allows its use in medical applications requiring autoclave and steam sterilization. However, it has low resistance to some solvents and undergoes weathering
; this weathering instability can be offset by adding other materials into the polymer.
Polysulfone allows easy manufacturing of membranes, with reproducible properties and controllable size of pores down to 40 nanometres. Such membranes can be used in applications like hemodialysis
, waste water recovery, food and beverage processing, and gas separation. These polymers are also used in the automotive and electronic industries. Filter cartridges made from polysulfone membranes offer extremely high flow rates at very low differential pressures when compared with Nylon or polypropylene media. Additionally filter cartridges made from polysulfone can be sterilized with in line steam or in the autoclave with out loss of integrity up to 50 times.
Polysulfone can be reinforced with glass fibers. The resulting composite material
has twice the tensile strength and three time increase of its modulus
.
Polysulfone is used as a dielectric
in capacitor
s.
Polysulfone is commercially available from Solvay Advanced Polymers, BASF
, and PolyOne Corporation
.
Polysulfone is often used as a copolymer. Recently sulfonated polyethersulfones (SPES) have been studied as a promising material candidate among many other aromatic hydrocarbon based polymers for highly durable, proton exchange membrane in proton exchange membrane fuel cells applications. Several reviews have reported many progress on studying the durability of many reports on this work.. The biggest challenge for SPES application in fuel cells is improving its chemical durability. Under oxidative environment, SPES can undergo sulfonic group detachment and main chain scission. However the latter is more dominant, midpoint scission and unzip mechanism have been proposed as the degradation mechanism depending on the strength of the polymer backbone.
Polysulfone is used as filtration media. The pore size can be very small, down to 0.2 µm or less for use in filter sterilization.
Polysulfone was the primary component of the gold-plated Lunar Extravehicular Visor Assembly, the iconic gold-film visor portion of the Apollo space-suits
worn by Apollo astronauts during their lunar excursions.
Thermoplastic
Thermoplastic, also known as a thermosoftening plastic, is a polymer that turns to a liquid when heated and freezes to a very glassy state when cooled sufficiently...
polymers. These polymers are known for their toughness and stability at high temperatures. They contain the subunit aryl
Arene
Arene or Arênê or Arène may refer to:*an aromatic hydrocarbon*Arene , a genus of marine snails in the family Areneidae*Arene , the wife of Aphareus and mother of Idas and Lynceus in Greek mythology...
-SO2-aryl, the defining feature of which is the sulfone
Sulfone
A sulfone is a chemical compound containing a sulfonyl functional group attached to two carbon atoms. The central hexavalent sulfur atom is double bonded to each of two oxygen atoms and has a single bond to each of two carbon atoms, usually in two separate hydrocarbon substituents.-IUPAC name and...
group. Polysulfones were introduced in 1965 by Union Carbide
Union Carbide
Union Carbide Corporation is a wholly owned subsidiary of The Dow Chemical Company. It currently employs more than 2,400 people. Union Carbide primarily produces chemicals and polymers that undergo one or more further conversions by customers before reaching consumers. Some are high-volume...
. Due to the high cost of raw materials and processing, polysulfones are used in specialty applications and often are a superior replacement for polycarbonate
Polycarbonate
PolycarbonatePhysical PropertiesDensity 1.20–1.22 g/cm3Abbe number 34.0Refractive index 1.584–1.586FlammabilityV0-V2Limiting oxygen index25–27%Water absorption – Equilibrium0.16–0.35%Water absorption – over 24 hours0.1%...
s.
Production
A typical polysulfone is produced by the reaction of a diphenolPhenol
Phenol, also known as carbolic acid, phenic acid, is an organic compound with the chemical formula C6H5OH. It is a white crystalline solid. The molecule consists of a phenyl , bonded to a hydroxyl group. It is produced on a large scale as a precursor to many materials and useful compounds...
and bis(4-chlorophenyl)sulfone, forming a polyether by elimination of sodium chloride
Sodium chloride
Sodium chloride, also known as salt, common salt, table salt or halite, is an inorganic compound with the formula NaCl. Sodium chloride is the salt most responsible for the salinity of the ocean and of the extracellular fluid of many multicellular organisms...
:
- n HOC6H4OH + n (ClC6H4)2SO24,4'-Dichlorodiphenyl sulfone4,4'-Dichlorodiphenyl sulfone, abbreviated as DCDPS, is an organic sulfone with the formula 2SO2. It is most commonly used as a precursor to polymers that are rigid and temperature resistant such as Victrex or Udel...
+ n Na2CO3 → [OC6H4OC6H4SO2C6H4]n + 2n NaCl + n H2O + n CO2
The diphenol is typically bisphenol-A or, 1,4-dihydroxybenzene
Hydroquinone
Hydroquinone, also benzene-1,4-diol or quinol, is an aromatic organic compound that is a type of phenol, having the chemical formula C6H42. Its chemical structure, shown in the table at right, has two hydroxyl groups bonded to a benzene ring in a para position. It is a white granular solid...
. Such step polymerizations require highly pure monomer to ensure high molecular weight products.
Chemical and physical properties
These polymers are rigid, high-strength, and transparent, retaining these properties between −100 °C and 150 °C. It has very high dimensional stability; the size change when exposed to boiling water or 150 °C air or steam generally falls below 0.1%. Its glass transition temperature is 185 °C.Polysulfone is highly resistant to mineral acid
Mineral acid
A mineral acid is an acid derived from one or more inorganic compounds. A mineral acid is not organic and all mineral acids release hydrogen ions when dissolved in water.-Characteristics:...
s, alkali
Alkali
In chemistry, an alkali is a basic, ionic salt of an alkali metal or alkaline earth metal element. Some authors also define an alkali as a base that dissolves in water. A solution of a soluble base has a pH greater than 7. The adjective alkaline is commonly used in English as a synonym for base,...
, and electrolyte
Electrolyte
In chemistry, an electrolyte is any substance containing free ions that make the substance electrically conductive. The most typical electrolyte is an ionic solution, but molten electrolytes and solid electrolytes are also possible....
s, in pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
ranging from 2 to 13. It is resistant to oxidizing agents, therefore it can be cleaned by bleach
Bleach
Bleach refers to a number of chemicals that remove color, whiten, or disinfect, often via oxidation. Common chemical bleaches include household chlorine bleach , lye, oxygen bleach , and bleaching powder...
es. It is also resistant to surfactant
Surfactant
Surfactants are compounds that lower the surface tension of a liquid, the interfacial tension between two liquids, or that between a liquid and a solid...
s and hydrocarbon
Hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls....
oil
Oil
An oil is any substance that is liquid at ambient temperatures and does not mix with water but may mix with other oils and organic solvents. This general definition includes vegetable oils, volatile essential oils, petrochemical oils, and synthetic oils....
s. It is not resistant to low-polar organic solvents (e.g. ketone
Ketone
In organic chemistry, a ketone is an organic compound with the structure RCR', where R and R' can be a variety of atoms and groups of atoms. It features a carbonyl group bonded to two other carbon atoms. Many ketones are known and many are of great importance in industry and in biology...
s and chlorinated hydrocarbons), and aromatic hydrocarbon
Aromatic hydrocarbon
An aromatic hydrocarbon or arene is a hydrocarbon with alternating double and single bonds between carbon atoms. The term 'aromatic' was assigned before the physical mechanism determining aromaticity was discovered, and was derived from the fact that many of the compounds have a sweet scent...
s. Mechanically, polysulfone has high compaction resistance, recommending its use under high pressures. It is also stable in aqueous acids and bases and many non-polar solvents; however it is soluble in dichloromethane and methylpyrrolidone
Methylpyrrolidone
N-Methyl-2-pyrrolidone is a chemical compound with 5-membered lactam structure. It is a clear to slightly yellow liquid miscible with water and solvents like ethyl acetate, chloroform, benzene and lower alcohols or ketones. It also belongs to the class of dipolar aprotic solvents which includes...
.
Polyethersulfone (PES) is a similar polymer with low protein retention.
Applications
Polysulfone has the highest service temperature of all melt-processable thermoplastics. Its resistance to high temperatures gives it a role of a flame retardantFlame retardant
Flame retardants are chemicals used in thermoplastics, thermosets, textiles and coatings that inhibit or resist the spread of fire. These can be separated into several different classes of chemicals:...
, without compromising its strength that usually results from addition of flame retardants. Its high hydrolysis stability allows its use in medical applications requiring autoclave and steam sterilization. However, it has low resistance to some solvents and undergoes weathering
Weathering
Weathering is the breaking down of rocks, soils and minerals as well as artificial materials through contact with the Earth's atmosphere, biota and waters...
; this weathering instability can be offset by adding other materials into the polymer.
Polysulfone allows easy manufacturing of membranes, with reproducible properties and controllable size of pores down to 40 nanometres. Such membranes can be used in applications like hemodialysis
Hemodialysis
In medicine, hemodialysis is a method for removing waste products such as creatinine and urea, as well as free water from the blood when the kidneys are in renal failure. Hemodialysis is one of three renal replacement therapies .Hemodialysis can be an outpatient or inpatient therapy...
, waste water recovery, food and beverage processing, and gas separation. These polymers are also used in the automotive and electronic industries. Filter cartridges made from polysulfone membranes offer extremely high flow rates at very low differential pressures when compared with Nylon or polypropylene media. Additionally filter cartridges made from polysulfone can be sterilized with in line steam or in the autoclave with out loss of integrity up to 50 times.
Polysulfone can be reinforced with glass fibers. The resulting composite material
Composite material
Composite materials, often shortened to composites or called composition materials, are engineered or naturally occurring materials made from two or more constituent materials with significantly different physical or chemical properties which remain separate and distinct at the macroscopic or...
has twice the tensile strength and three time increase of its modulus
Young's modulus
Young's modulus is a measure of the stiffness of an elastic material and is a quantity used to characterize materials. It is defined as the ratio of the uniaxial stress over the uniaxial strain in the range of stress in which Hooke's Law holds. In solid mechanics, the slope of the stress-strain...
.
Polysulfone is used as a dielectric
Dielectric
A dielectric is an electrical insulator that can be polarized by an applied electric field. When a dielectric is placed in an electric field, electric charges do not flow through the material, as in a conductor, but only slightly shift from their average equilibrium positions causing dielectric...
in capacitor
Capacitor
A capacitor is a passive two-terminal electrical component used to store energy in an electric field. The forms of practical capacitors vary widely, but all contain at least two electrical conductors separated by a dielectric ; for example, one common construction consists of metal foils separated...
s.
Polysulfone is commercially available from Solvay Advanced Polymers, BASF
BASF
BASF SE is the largest chemical company in the world and is headquartered in Germany. BASF originally stood for Badische Anilin- und Soda-Fabrik . Today, the four letters are a registered trademark and the company is listed on the Frankfurt Stock Exchange, London Stock Exchange, and Zurich Stock...
, and PolyOne Corporation
PolyOne Corporation
PolyOne Corporation is a global provider of specialized polymer materials, services, and solutions. PolyOne has operations in thermoplastic compounds, specialty polymer formulations, color and additive systems, thermoplastic resin distribution, and vinyl resins...
.
Polysulfone is often used as a copolymer. Recently sulfonated polyethersulfones (SPES) have been studied as a promising material candidate among many other aromatic hydrocarbon based polymers for highly durable, proton exchange membrane in proton exchange membrane fuel cells applications. Several reviews have reported many progress on studying the durability of many reports on this work.. The biggest challenge for SPES application in fuel cells is improving its chemical durability. Under oxidative environment, SPES can undergo sulfonic group detachment and main chain scission. However the latter is more dominant, midpoint scission and unzip mechanism have been proposed as the degradation mechanism depending on the strength of the polymer backbone.
Polysulfone is used as filtration media. The pore size can be very small, down to 0.2 µm or less for use in filter sterilization.
Polysulfone was the primary component of the gold-plated Lunar Extravehicular Visor Assembly, the iconic gold-film visor portion of the Apollo space-suits
Apollo/Skylab A7L
The A7L Apollo & Skylab spacesuit is the primary pressure suit worn by NASA astronauts for Project Apollo, the three manned Skylab flights, and the Apollo-Soyuz Test Project between 1968 and the termination of the Apollo program in 1975. The "A7L" designation is used by NASA as the seventh Apollo...
worn by Apollo astronauts during their lunar excursions.