Polysulfone

Polysulfone
Polysulfone repeating unit.

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 polycarbonates.

Contents

Production

A typical polysulfone is produced by the reaction of a diphenol and bis(4-chlorophenyl)sulfone, forming a polyether by elimination of sodium chloride:

n HOC6H4OH + n (ClC6H4)2SO2 + n Na2CO3 → [OC6H4OC6H4SO2C6H4]n + 2n NaCl + n H2O + n CO2

The diphenol is typically bisphenol-A or, 1,4-dihydroxybenzene. Such step polymerizations require highly pure monomer to ensure high molecular weight products.[1]

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 acids, alkali, and electrolytes, in pH ranging from 2 to 13. It is resistant to oxidizing agents, therefore it can be cleaned by bleaches. It is also resistant to surfactants and hydrocarbon oils. It is not resistant to low-polar organic solvents (e.g. ketones and chlorinated hydrocarbons), and aromatic hydrocarbons. 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.[1]

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 retardant, 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 capacitors.

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[2]. Several reviews have reported many progress on studying the durability of many reports on this work.[3]. 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.[4]

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.[5]

See also

References

  1. ^ a b David Parker, Jan Bussink, Hendrik T. van de Grampel, Gary W. Wheatley, Ernst-Ulrich Dorf, Edgar Ostlinning, Klaus Reinking, "Polymers, High-Temperature" in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH: Weinheim. DOI: 10.1002/14356007.a21_449
  2. ^ Hickner et al. Alternative polymer systems for proton exchange membranes (PEMs). Chemical Reviews (2004) vol. 104 (10) pp. 4587-4611.Link
  3. ^ Borup et al. Scientific aspects of polymer electrolyte fuel cell durability and degradation. Chemical Reviews (2007) vol. 107 (10) pp. 3904-3951.Link
  4. ^ Lawrence and Yamaguchi. The degradation mechanism of sulfonated poly(arylene ether sulfone)s in an oxidative environment. Journal of Membrane Science (2008) vol. 325 (2) pp. 633-640. Link
  5. ^ Lunar Extravehicular Visor Assembly (LEVA). NASA. Retrieved 21 July 2010.

Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • Polysulfone — Polysulfone,   Abkürzung PSU, hochtemperaturbeständige Kunststoffe mit folgender Struktureinheit:   Polysulfone werden aus Dichlordiphenylsulfon und Bisphenol A hergestellt und können Dauertemperaturen von 150 170 ºC ausgesetzt werden. Sie sind… …   Universal-Lexikon

  • polysulfone — ▪ chemical compound       any of a class of resinous organic chemical compounds belonging to the family of polymers in which the main structural chain most commonly consists of benzene rings linked together by sulfonyl (−SO2−), ether (−O−), and… …   Universalium

  • Polysulfone — Motif de répétition d un polysulfone. Les polysulfones (PSU) sont une famille de polymères thermoplastiques. Ils s obtient par réaction entre un diphénol et du bis(4 chlorophényl)sulfone, formant un éther oxyde par élimination de chlorure de… …   Wikipédia en Français

  • polysulfone — polisulfonas statusas T sritis chemija apibrėžtis Polimeras, kurio makromolekulės pagrindinėje grandinėje yra –SO₂– grupių. atitikmenys: angl. polysulfone rus. полисульфон …   Chemijos terminų aiškinamasis žodynas

  • polysulfone — noun Any of a several classes of thermoplastic polymers whose repeat units contain a sulfone See Also: polyethersulfone …   Wiktionary

  • polysulfone — poly·sul·fone (pol″e sulґfōn) a synthetic thermoplastic polymer used as a hemodialyzer membrane …   Medical dictionary

  • Thermoplastics — A thermoplastic is a plastic that melts to a liquid when heated and freezes to a brittle, very glassy state when cooled sufficiently. Most thermoplastics are high molecular weight polymers whose chains associate through weak Van der Waals forces… …   Wikipedia

  • Polybutylene — Other names polybutene 1, poly(1 butene), PB 1 Identifiers …   Wikipedia

  • Polyethersulfon — Strukturformel Allgemeines Name Polyethersulfon Andere Namen PESU PES Poly(oxy 1,4 phenylsulfonyl 1,4 phenyl) …   Deutsch Wikipedia

  • Liste Des Codes Des Plastiques, Caoutchouc Et Latex — Liste des codes des polymères La liste des codes des polymères (à ne pas confondre avec le Code d identification des résines pour leur tri et recyclage, norme DIN 6120) est établie à partir des codes des plastiques (thermoplastiques et… …   Wikipédia en Français

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”