Wikipedia:WikiProject Chemicals/Chembox validation/VerifiedDataSandbox and Polyethylene glycol: Difference between pages

{{Short description|Chemical compound}}

{{distinguish|text=[[Ethylene glycol]] or [[Diethylene glycol]] or [[Polypropylene glycol]] or [[Propylene glycol]]}}

{{For|medical uses of polyethylene glycol|Macrogol}}

{{Use dmy dates|date=December 2021}}

{{Chembox

| Watchedfields = changed

| verifiedrevid = 477163023

| Name =

| ImageFile = PEG Structural Formula V1.svg

| IUPACName = poly(oxyethylene) <small>{structure-based}</small>,<br> poly(ethylene oxide) <small>{source-based}</small><ref>{{cite journal|title=Nomenclature of regular single-strand organic polymers|journal=Pure and Applied Chemistry|year=2002|volume=74|issue=10|pages=1921–1956|doi=10.1351/pac200274101921| vauthors = Kahovec J, Fox RB, Hatada K |doi-access=free}}</ref>

| OtherNames = Kollisolv, Carbowax, GoLYTELY, GlycoLax, Fortrans, TriLyte, Colyte, Halflytely, [[macrogol]], MiraLAX, MoviPrep

| SystematicName =

| Section1 = {{Chembox Identifiers

| UNII_Ref = {{fdacite|correct|FDA}}

| Abbreviations = PEG

| UNII = 3WJQ0SDW1A

| ChEMBL = 1201478

| ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}}

| ChemSpiderID = none}}

| Section2 = {{Chembox Properties

| MolarMass = {{nowrap|44.05n + 18.02'' g/mol}}

| Density = 1.125<ref name="chemsrc">{{Cite web|url=https://www.chemsrc.com/en/cas/25322-68-3_766012.html|title=Poly(ethylene glycol)|website = ChemSrc|date = 7 January 2020}}</ref>

| Section3 =

| Section5 =

| Section6 = {{Chembox Pharmacology

| ATCCode_prefix = A06

| ATCCode_suffix = AD15}}

| Section7 = {{Chembox Hazards

| FlashPt = {{convert|182|-|287|C|C F K|disp=output only}}

| AutoignitionPtC =

'''Polyethylene glycol''' ('''PEG'''; {{IPAc-en|ˌ|p|ɒ|l|i|ˈ|ɛ|θ|əl|ˌ|iː|n|_|ˈ|ɡ|l|aɪ|ˌ|k|ɒ|l|,_|-|ˈ|ɛ|θ|ɪ|l|-|,_|-|ˌ|k|ɔː|l}}) is a [[polyether]] compound derived from [[petroleum]] with many applications, from industrial manufacturing to [[medicine]]. PEG is also known as '''polyethylene oxide''' ('''PEO''') or '''polyoxyethylene''' ('''POE'''), depending on its [[molecular weight]]. The structure of PEG is commonly expressed as H−(O−CH₂−CH₂)_n−OH.<ref name=Ullmann>{{Ullmann |doi=10.1002/14356007.a21_579|title=Polyoxyalkylenes|year=2000| vauthors }}</ref>

==Uses==

=== Medical uses ===

{{Main|Macrogol|PEGylation}}

* Pharmaceutical-grade PEG is used as an [[excipient]] in many pharmaceutical products, in oral, topical, and parenteral dosage forms.<ref>{{Cite web |title=Polyethylene Glycol as Pharmaceutical Excipient |url=https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpharma.basf.com%2Fchemistry%2Fpolyethylene-glycols%3Fat_medium%3Ddisplay%26at_campaign%3Denp_baw_glob_en_sol_tra_wikipedia%26at_creation%3Dlanding-page_wikipedia_chemistry-page_basf-wikipedia-article%26at_channel%3Dwikipedia%26at_format%3Dchemistry-page%26at_variant%3Dbasf-wikipedia-article&data=05%7C01%7Clindsay.johnson%40basf.com%7C04fa892cf1414e3a369008da4b1bc61a%7Cecaa386bc8df4ce0ad01740cbdb5ba55%7C0%7C0%7C637904879896194972%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=1MhiWJiOVZ7zca21XVGr6KtMMsgsmxA%2BzPTLNbyvAKo%3D&reserved=0 |access-date=2021-04-27 |website=pharmaceutical.basf.com |language=en}}</ref>

* PEG is the basis of a number of [[laxative]]s (as ''MiraLax, RestoraLAX, etc.'').<ref name="Distillations" /> [[Whole bowel irrigation]] with polyethylene glycol and added [[electrolyte]]s is used for bowel preparation before [[surgery]] or [[colonoscopy]] or for children with constipation.<ref>{{cite web | url=https://medicaldialogues.in/partner/jbcpl/laxolite | title=Polyethyleneglycol (PEG 4000 ) {{!}} Laxolite {{!}} Medical Dialogues | publisher=[[Medical Dialogues]] | date=19 January 2021 | access-date=19 January 2021}}</ref> [[Macrogol]] (with brand names such as Laxido, [[Movicol]] and [[Miralax]]) is the generic name for polyethylene glycol used as a laxative. The name may be followed by a number which represents the average molecular weight (e.g. macrogol 3350, macrogol 4000 or macrogol 6000).

* The possibility that PEG could be used to fuse [[axon]]s is being explored by researchers studying [[Nerve injury|peripheral nerve]] and [[spinal cord injury]].<ref name="Distillations"/>

*An example of PEG [[hydrogel]]s (see [[#Biological uses|Biological uses]] section) in a therapeutic has been theorized by Ma et al. They propose using the hydrogel to address [[Periodontal disease|periodontitis]] (gum disease) by encapsulating [[stem cell]]s in the gel that promote healing in the gums.<ref>{{cite journal | vauthors = Ma Y, Ji Y, Zhong T, Wan W, Yang Q, Li A, Zhang X, Lin M | display-authors = 6 | title = Bioprinting-Based PDLSC-ECM Screening for in Vivo Repair of Alveolar Bone Defect Using Cell-Laden, Injectable and Photocrosslinkable Hydrogels | journal = ACS Biomaterials Science & Engineering | volume = 3 | issue = 12 | pages = 3534–3545 | date = December 2017 | pmid = 33445388 | doi = 10.1021/acsbiomaterials.7b00601 }}</ref> The gel with encapsulated stem cells was to be injected into the site of disease and crosslinked to create the microenvironment required for the stem cells to function.

*[[PEGylation]] of [[Adenoviridae|adenoviruses]] for [[gene therapy]] can help prevent adverse reactions due to pre-existing adenovirus immunity.<ref name="pmid19780714">{{cite journal | vauthors=Seregin SS, Amalfitano A | title=Overcoming pre-existing adenovirus immunity by genetic engineering of adenovirus-based vectors | journal=[[Expert Opinion on Biological Therapy]] | volume=9 | issue=12 | pages=1521–1531 | year=2009 | doi = 10.1517/14712590903307388 | pmid=19780714 | s2cid=21927486 }}</ref>

* A [[PEGylation|PEGylated]] lipid is used as an excipient in both the [[Moderna#COVID-19 vaccine|Moderna]] and [[Tozinameran|Pfizer–BioNTech vaccine]]s for [[SARS-CoV-2]]. Both [[RNA vaccines]] consist of [[messenger RNA]], or mRNA, encased in a bubble of oily molecules called [[lipids]]. Proprietary lipid technology is used for each. In both vaccines, the bubbles are coated with a stabilizing molecule of polyethylene glycol.{{medcn|date=December 2020}} PEG could trigger allergic reaction,<ref name="cekdis20">{{cite journal | vauthors = Cabanillas B, Akdis CA, Novak N | title = Allergic reactions to the first COVID-19 vaccine: A potential role of polyethylene glycol? | journal = Allergy | volume = 76 | issue = 6 | pages = 1617–1618 | date = June 2021 | pmid = 33320974 | doi = 10.1111/all.14711 | s2cid = 229284320 | doi-access = free }}</ref> and allergic reactions are the driver for both the United Kingdom and Canadian regulators to issue an advisory, noting that: two "individuals in the U.K. ... were treated and have recovered" from [[anaphylactic]] shock.<ref name=mhra>{{cite web | vauthors = Bostock N |publisher=GP |title=MHRA warning after allergic reactions in NHS staff given COVID-19 vaccine |url=https://www.gponline.com/mhra-warning-allergic-reactions-nhs-staff-given-covid-19-vaccine/article/1702322 |date=9 December 2020 |access-date=9 December 2020 |archive-date=9 December 2020 |archive-url=https://web.archive.org/web/20201209163321/https://www.gponline.com/mhra-warning-allergic-reactions-nhs-staff-given-covid-19-vaccine/article/1702322 |url-status=live |name-list-style=vanc }}</ref><ref name="hc12dec">{{cite web |title=Pfizer-BioNTech COVID-19 vaccine: Health Canada recommendations for people with serious allergies |url=https://healthycanadians.gc.ca/recall-alert-rappel-avis/hc-sc/2020/74543a-eng.php |publisher=Health Canada |date=12 December 2020}}</ref> The US CDC stated that in their jurisdiction six cases of "severe allergic reaction" had been recorded from more than 250,000 vaccinations, and of those six only one person had a "history of vaccination reactions".<ref name="afgm">{{cite news | vauthors = Furtula A, Jordans F |title=EU regulator gives conditional approval to Pfizer-BioNTech COVID-19 vaccine |url=https://www.theglobeandmail.com/world/article-eu-regulator-gives-conditional-approval-to-pfizer-biontech-covid-19/ |agency=Reuters |publisher=The Globe and Mail Inc |date=21 December 2020}}</ref>

===Chemical uses===

[[File:MaryRose-conservation2.jpg|thumb|The remains of the 16th century [[carrack]] ''[[Mary Rose]]'' undergoing conservation treatment with PEG in the 1980s]]

[[File:Terra Cotta Warriors, Guardians of China’s First Emperor 1.jpg|thumb|Terra cotta warrior, showing traces of original color]]

* Polyethylene glycol is also commonly used as a polar stationary phase for [[gas chromatography]], as well as a [[Coolant|heat transfer fluid]] in electronic testers.

* PEG is frequently used to [[Conservation and restoration of waterlogged wood|preserve waterlogged wood]] and other organic artifacts that have been salvaged from underwater archaeological contexts, as was the case with the warship ''[[Vasa (ship)|Vasa]]'' in Stockholm,<ref>{{cite book | vauthors = Kvarning LÅ, Ohrelius B | date = 1998 | title = The Vasa – The Royal Ship | isbn = 91-7486-581-1 | pages = 133–141 | publisher = Atlantis }}</ref> and similar cases. It replaces water in wooden objects, making the wood dimensionally stable and preventing warping or shrinking of the wood when it dries.<ref name="Distillations"/> In addition, PEG is used when working with [[green wood]] as a stabilizer, and to prevent shrinkage.<ref>{{cite web | url = https://www.rockler.com/anti-freeze-is-not-a-green-wood-stabilizer | title = Anti-Freeze is Not a Green Wood Stabilizer – Buzz Saw | work = The Rockler Blog | archive-url = https://web.archive.org/web/20220117170449/https://www.rockler.com/anti-freeze-is-not-a-green-wood-stabilizer | archive-date = 17 January 2022 | date = 2 May 2006 | access-date = 30 November 2012 }}</ref>

* PEG has been used to preserve the painted colors on [[Terracotta Army|Terracotta Warriors]] unearthed at a UNESCO World Heritage site in China.<ref>{{cite web | url=https://www.tum.de/en/about-tum/news/press-releases/short/article/32290/ | title=Conservators preserve the paint layers of the Terracotta Army | vauthors = Reiffert S | date=18 March 2015 | website=tum.de | publisher=Technische Universität München | access-date=19 December 2015 | archive-date=22 December 2015 | archive-url=https://web.archive.org/web/20151222113322/https://www.tum.de/en/about-tum/news/press-releases/short/article/32290/ | url-status=dead }}</ref> These painted artifacts were created during the [[Qin Shi Huang]] (first emperor of China) era. Within 15 seconds of the terra-cotta pieces being unearthed during excavations, the lacquer beneath the paint begins to curl after being exposed to the dry [[Xi'an]] air. The paint would subsequently flake off in about four minutes. The German Bavarian State Conservation Office developed a PEG preservative that when immediately applied to unearthed artifacts has aided in preserving the colors painted on the pieces of clay soldiers.<ref>{{cite journal | title=Terra-Cotta Warriors in Color | journal=[[National Geographic (magazine)|National Geographic]] |date=June 2012 | vauthors = Larmer B | volume=221 |number=6 |pages=74–87}}</ref>

* PEG is often used (as an internal calibration compound) in [[mass spectrometry]] experiments, with its characteristic fragmentation pattern allowing accurate and reproducible tuning.

* PEG derivatives, such as [[narrow range ethoxylate]]s, are used as [[surfactant]]s.

* PEG has been used as the hydrophilic block of [[amphiphilic]] block [[copolymers]] used to create some [[polymersome]]s.<ref>{{cite journal | vauthors = Rameez S, Alosta H, Palmer AF | title = Biocompatible and biodegradable polymersome encapsulated hemoglobin: a potential oxygen carrier | journal = Bioconjugate Chemistry | volume = 19 | issue = 5 | pages = 1025–32 | date = May 2008 | pmid = 18442283 | doi = 10.1021/bc700465v }}</ref>

*PEG is a component of the propellent used in [[UGM-133 Trident II|UGM-133M Trident II Missiles]], in service with the [[United States Navy]].<ref name="History Facts 2">{{cite web|title=Facts: Polaris Poseidon Trident|url=http://www.ssp.navy.mil/about/history_facts_2.html|website = Strategic Systems Programs|publisher = U.S. Navy}}</ref>

* PEG has been used as a solvent for aryl [[thioether]] synthesis.<ref>{{cite journal | vauthors = Firouzabadi H, Iranpoor N, Gholinejad M | title = One-Pot Thioetherification of Aryl Halides Using Thiourea and Alkyl Bromides Catalyzed by Copper(I) Iodide Free from Foul-Smelling Thiols in Wet Polyethylene Glycol (PEG 200)| journal = Advanced Synthesis & Catalysis | volume = 352 | issue = 18 | pages = 119-24 | date = January 2010 | doi = 10.1002/adsc.200900671}}</ref>

===Biological uses===

*An example study was done using PEG-diacrylate hydrogels to recreate vascular environments with the encapsulation of [[Endothelium|endothelial]] cells and [[macrophage]]s. This model furthered vascular disease modeling and isolated macrophage phenotype's effect on blood vessels.<ref>{{Cite journal| vauthors = Moore EM, Ying G, West JL |date=March 2017|title=Macrophages Influence Vessel Formation in 3D Bioactive Hydrogels|journal=Advanced Biosystems |language=en |volume=1|issue=3|pages=1600021|doi=10.1002/adbi.201600021|s2cid=102369711|doi-access=free}}</ref>

*PEG is commonly used as a crowding agent in ''in vitro'' assays to mimic highly crowded cellular conditions.<ref name=":0">{{cite journal | vauthors = Ganji M, Docter M, Le Grice SF, Abbondanzieri EA | title = DNA binding proteins explore multiple local configurations during docking via rapid rebinding | journal = Nucleic Acids Research | volume = 44 | issue = 17 | pages = 8376–8384 | date = September 2016 | pmid = 27471033 | pmc = 5041478 | doi = 10.1093/nar/gkw666 }}</ref> Although polyethylene glycol is considered biologically inert, it can form [[Non-covalent interaction|non-covalent]] complexes with monovalent [[cations]] such as [[Na⁺|Na⁺]], [[Potassium|K⁺]], Rb⁺, and Cs⁺, affecting [[Equilibrium constant|equilibrium constants]] of biochemical reactions.<ref>{{cite journal | vauthors = Bielec K, Kowalski A, Bubak G, Witkowska Nery E, Hołyst R | title = Ion Complexation Explains Orders of Magnitude Changes in the Equilibrium Constant of Biochemical Reactions in Buffers Crowded by Nonionic Compounds | journal = The Journal of Physical Chemistry Letters | volume = 13 | issue = 1 | pages = 112–117 | date = January 2022 | pmid = 34962392 | pmc = 8762655 | doi = 10.1021/acs.jpclett.1c03596 }}</ref><ref>{{Cite journal | vauthors = Breton MF, Discala F, Bacri L, Foster D, Pelta J, Oukhaled A |date=2013-07-03 |title=Exploration of Neutral Versus Polyelectrolyte Behavior of Poly(ethylene glycol)s in Alkali Ion Solutions using Single-Nanopore Recording |journal=The Journal of Physical Chemistry Letters |language=en |volume=4 |issue=13 |pages=2202–2208 |doi=10.1021/jz400938q |issn=1948-7185}}</ref>

* PEG is commonly used as a [[precipitant]] for plasmid DNA isolation and [[X-ray crystallography|protein crystallization]]. [[X-ray diffraction]] of protein crystals can reveal the atomic structure of the proteins.

* PEG is used to fuse two different types of cells, most often B-cells and myelomas in order to create [[hybridomas]]. [[César Milstein]] and [[Georges J. F. Köhler]] originated this technique, which they used for antibody production, winning a [[Nobel Prize in Physiology or Medicine]] in 1984.<ref name="Distillations"/>

* In [[microbiology]], PEG precipitation is used to concentrate viruses. PEG is also used to induce complete fusion (mixing of both inner and outer leaflets) in liposomes reconstituted ''in vitro''.

* [[Gene therapy]] vectors (such as viruses) can be PEG-coated to shield them from inactivation by the immune system and to de-target them from organs where they may build up and have a toxic effect.<ref>{{cite journal | vauthors = Kreppel F, Kochanek S | title = Modification of adenovirus gene transfer vectors with synthetic polymers: a scientific review and technical guide | journal = Molecular Therapy | volume = 16 | issue = 1 | pages = 16–29 | date = January 2008 | pmid = 17912234 | doi = 10.1038/sj.mt.6300321 | doi-access = free }}</ref> The size of the PEG polymer has been shown to be important, with larger polymers achieving the best immune protection.

* PEG is a component of [[stable nucleic acid lipid particle]]s (SNALPs) used to package [[siRNA]] for use ''in vivo''.<ref>{{cite journal | vauthors = Rossi JJ | title = RNAi therapeutics: SNALPing siRNAs in vivo | journal = Gene Therapy | volume = 13 | issue = 7 | pages = 583–584 | date = April 2006 | pmid = 17526070 | doi = 10.1038/sj.gt.3302661 | s2cid = 7232293 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Geisbert TW, Lee AC, Robbins M, Geisbert JB, Honko AN, Sood V, Johnson JC, de Jong S, Tavakoli I, Judge A, Hensley LE, Maclachlan I | display-authors = 6 | title = Postexposure protection of non-human primates against a lethal Ebola virus challenge with RNA interference: a proof-of-concept study | journal = Lancet | volume = 375 | issue = 9729 | pages = 1896–1905 | date = May 2010 | pmid = 20511019 | pmc = 7138079 | doi = 10.1016/S0140-6736(10)60357-1 }} (free with registration)</ref>

* In [[blood banking]], PEG is used as a [[potentiator]] to enhance detection of [[antigen]]s and [[antibodies]].<ref name="Distillations"/><ref>{{cite book | vauthors = Harmening DM | title=Modern Blood Banking & Transfusion Practices | publisher=F. A. Davis Company | year=2005 | isbn=978-0-8036-1248-8}}</ref>

* When working with [[phenol]] in a laboratory situation, [[PEG 300]] can be used on phenol skin burns to deactivate any residual phenol.<ref>{{cite journal | vauthors = Monteiro-Riviere NA, Inman AO, Jackson H, Dunn B, Dimond S | title = Efficacy of topical phenol decontamination strategies on severity of acute phenol chemical burns and dermal absorption: in vitro and in vivo studies in pig skin | journal = Toxicology and Industrial Health | volume = 17 | issue = 4 | pages = 95–104 | date = May 2001 | pmid = 12479505 | doi = 10.1191/0748233701th095oa | s2cid = 46229131 }}</ref>

* In [[biophysics]], polyethylene glycols are the molecules of choice for the functioning ion channels diameter studies, because in aqueous solutions they have a spherical shape and can block ion channel conductance.<ref>{{cite journal | vauthors = Krasilnikov OV, Sabirov RZ, Ternovsky VI, Merzliak PG, Muratkhodjaev JN | title = A simple method for the determination of the pore radius of ion channels in planar lipid bilayer membranes | journal = FEMS Microbiology Immunology | volume = 5 | issue = 1–3 | pages = 93–100 | date = September 1992 | pmid = 1384601 | doi = 10.1016/0378-1097(92)90079-4 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Bárcena-Uribarri I, Thein M, Maier E, Bonde M, Bergström S, Benz R | title = Use of nonelectrolytes reveals the channel size and oligomeric constitution of the Borrelia burgdorferi P66 porin | journal = PLOS ONE | volume = 8 | issue = 11 | pages = e78272 | year = 2013 | pmid = 24223145 | pmc = 3819385 | doi = 10.1371/journal.pone.0078272 | doi-access = free | bibcode = 2013PLoSO...878272B }}</ref>

===Commercial uses===

* PEG is the basis of many [[Moisturizer|skin creams]] (as ''[[cetomacrogol]]'') and [[personal lubricant]]s.

* PEG is used in a number of [[toothpaste]]s<ref name="Distillations">{{cite journal| vauthors = Kean S |title=Chemical Hope|journal=Distillations|date=2017|volume=2|issue=4|page=5|url=https://www.sciencehistory.org/distillations/magazine/chemical-hope|access-date=22 March 2018}}</ref> as a [[dispersant]]. In this application, it binds water and helps keep [[xanthan gum]] uniformly distributed throughout the toothpaste.

* PEG is under investigation for use in [[Liquid Armor|liquid body armor]], and in [[tattoo]]s to monitor [[diabetes]].<ref>{{cite news|publisher = BBC News|date = 1 September 2002|title = Tattoo to monitor diabetes|url = http://news.bbc.co.uk/2/hi/health/2225404.stm}}</ref>

* Polymer segments derived from PEG [[polyols]] impart flexibility to [[polyurethane]]s for applications such as elastomeric [[fiber]]s ([[spandex]]) and [[foam]] cushions.

* In low-[[molecular weight|molecular-weight]] formulations (e.g. [[PEG 400]]), it is used in [[Hewlett-Packard]] designjet [[Printer (computing)|printers]] as an ink solvent and lubricant for the print heads.

* PEG is used as an anti-foaming agent in food and drinks<ref>US Government – Food and Drug Agency {{cite web |url=https://www.fda.gov/food/ingredientspackaginglabeling/foodadditivesingredients/ucm091048.htm |title=Food Additive Status List |website=[[Food and Drug Administration]] |access-date=2 May 2017}}</ref> – its [[INS number]] is 1521<ref>{{cite web|url=http://www.codexalimentarius.net/web/index_en.jsp |title=Codex Alimentarius |work=codexalimentarius.net |url-status=unfit |archive-url=https://web.archive.org/web/20120107123157/http://www.codexalimentarius.net/web/index_en.jsp |archive-date=7 January 2012 }}</ref> or E1521 in the EU.<ref>{{cite web |url=http://www.food.gov.uk/safereating/chemsafe/additivesbranch/enumberlist |title=Current EU approved additives and their E Numbers |access-date=21 October 2010|publisher=UK Government – Food Standards Agency}}</ref>

===Industrial uses===

* A [[nitrate]] [[ester]]-plasticized polyethylene glycol ([[Solid-fuel rocket#Composite modified double base propellants|NEPE-75]]) is used in [[UGM-133 Trident II#Design|Trident II]] [[submarine-launched ballistic missile]] solid rocket fuel.<ref name=spinardi>{{cite book| vauthors = Spinardi G |title=From Polaris to Trident : the development of US fleet ballistic missile technology|url=https://archive.org/details/frompolaristotri00spin_389|url-access=limited|year=1994|publisher=Cambridge Univ. Press|location=Cambridge|isbn=978-0-521-41357-2|page=[https://archive.org/details/frompolaristotri00spin_389/page/n168 159]}}</ref>

* Dimethyl ethers of PEG are the key ingredient of [[Selexol]], a solvent used by [[coal]]-burning, [[integrated gasification combined cycle]] (IGCC) power plants to remove [[carbon dioxide]] and [[hydrogen sulfide]] from the [[syngas]] stream.

* PEG has been used as the gate insulator in an electric double-layer transistor to induce superconductivity in an insulator.<ref>{{cite journal | vauthors = Ueno K, Nakamura S, Shimotani H, Ohtomo A, Kimura N, Nojima T, Aoki H, Iwasa Y, Kawasaki M | display-authors = 6 | title = Electric-field-induced superconductivity in an insulator | journal = Nature Materials | volume = 7 | issue = 11 | pages = 855–8 | date = November 2008 | pmid = 18849974 | doi = 10.1038/nmat2298 | bibcode = 2008NatMa...7..855U }}</ref>

* PEG is used as a polymer host for solid polymer electrolytes. Although not yet in commercial production, many groups around the globe are engaged in research on solid polymer electrolytes involving PEG, with the aim of improving their properties, and in permitting their use in batteries, electro-chromic display systems, and other products in the future.

* PEG is injected into industrial processes to reduce foaming in separation equipment.

* PEG is used as a [[Binder (material)|binder]] in the preparation of technical [[ceramic]]s.<ref>Schneider, Samuel J. (1991) ''Engineered Materials Handbook: Ceramics and Glasses'', Vol. 4. ASM International. {{ISBN|0-87170-282-7}}. p. 49.</ref>

* PEG was used as an additive to silver halide photographic [[Photolith film|emulsions]].

===Entertainment uses===

* PEG is used to extend the size and durability of very large [[soap bubbles]].

* PEG is the main ingredient in many [[personal lubricant]]s.{{citation needed|date=February 2024}} (Not to be confused with [[propylene glycol]].)

* PEG is the main ingredient in the paint (known as "fill") in [[paintball]]s.

== Health effects ==

PEG is considered biologically inert and safe by the U.S. [[FDA]].

However, a growing body of evidence shows the existence of a detectable level of anti-PEG [[antibodies]] in approximately 72% of the population, never treated with [[Pegylated|PEGylated]] drugs, based on plasma samples from 1990 to 1999.<ref>{{cite journal | vauthors = Yang Q, Lai SK | title = Anti-PEG immunity: emergence, characteristics, and unaddressed questions | journal = Wiley Interdisciplinary Reviews. Nanomedicine and Nanobiotechnology | volume = 7 | issue = 5 | pages = 655–77 | date = 2015 | pmid = 25707913 | pmc = 4515207 | doi = 10.1002/wnan.1339 }}</ref>{{Explain|date=April 2021|reason=what does this mean?}} Due to its ubiquity in a multitude of products and the large percentage of the population with antibodies to PEG, hypersensitive reactions to PEG are an increasing concern.<ref name=":1">{{cite journal | vauthors = Wenande E, Garvey LH | title = Immediate-type hypersensitivity to polyethylene glycols: a review | journal = Clinical and Experimental Allergy | volume = 46 | issue = 7 | pages = 907–22 | date = July 2016 | pmid = 27196817 | doi = 10.1111/cea.12760 | s2cid = 1247758 | url = https://pubmed.ncbi.nlm.nih.gov/27196817/ }}</ref><ref>{{cite journal | vauthors = Stone CA, Liu Y, Relling MV, Krantz MS, Pratt AL, Abreo A, Hemler JA, Phillips EJ | display-authors = 6 | title = Immediate Hypersensitivity to Polyethylene Glycols and Polysorbates: More Common Than We Have Recognized | journal = The Journal of Allergy and Clinical Immunology. In Practice | volume = 7 | issue = 5 | pages = 1533–1540.e8 | date = May 2019 | pmid = 30557713 | pmc = 6706272 | doi = 10.1016/j.jaip.2018.12.003 }}</ref> Allergy to PEG is usually discovered after a person has been diagnosed with an allergy to an increasing number of seemingly unrelated products, including processed foods, cosmetics, drugs, and other substances that contain PEG or were manufactured with PEG.<ref name=":1" />

==Available forms and nomenclature==

''PEG'', ''PEO'', and ''POE'' refer to an [[oligomer]] or polymer of [[ethylene oxide]]. The three names are chemically synonymous, but historically ''PEG'' is preferred in the biomedical field, whereas ''PEO'' is more prevalent in the field of polymer chemistry. Because different applications require different polymer chain lengths, ''PEG'' has tended to refer to oligomers and polymers with a molecular mass below 20,000{{nbsp}}g/mol, ''PEO'' to polymers with a molecular mass above 20,000{{nbsp}}g/mol, and ''POE'' to a polymer of any molecular mass.<ref>For example, in the [http://www.scientificpolymer.com/utils/search.asp online catalog] {{webarchive|url=https://web.archive.org/web/20061229131736/http://www.scientificpolymer.com/utils/search.asp |date=29 December 2006 }} of Scientific Polymer Products, Inc., poly(ethylene glycol) molecular weights run up to about 20,000, while those of poly(ethylene oxide) have six or seven digits.</ref> PEGs are prepared by [[polymerization]] of [[ethylene oxide]] and are commercially available over a wide range of molecular weights from 300{{nbsp}}g/mol to 10,000,000{{nbsp}}g/mol.<ref name=french2009angewandte/>

PEG and PEO are liquids or low-melting solids, depending on their [[molecular weight]]s. While PEG and PEO with different molecular weights find use in different applications, and have different physical properties (e.g. [[viscosity]]) due to chain length effects, their chemical properties are nearly identical. Different forms of PEG are also available, depending on the [[Radical initiator|initiator]] used for the polymerization process – the most common initiator is a monofunctional methyl ether PEG, or methoxypoly(ethylene glycol), abbreviated mPEG. Lower-molecular-weight PEGs are also available as purer oligomers, referred to as monodisperse, uniform, or discrete. Very high-purity PEG has recently been shown to be crystalline, allowing determination of a crystal structure by [[x-ray crystallography]].<ref name=french2009angewandte>{{cite journal | vauthors = French AC, Thompson AL, Davis BG | title = High-purity discrete PEG-oligomer crystals allow structural insight | journal = Angewandte Chemie | volume = 48 | issue = 7 | pages = 1248–52 | year = 2009 | pmid = 19142918 | doi = 10.1002/anie.200804623 | url = http://users.ox.ac.uk/~dplb0149/publication/pub108.pdf }}</ref> Since purification and separation of pure oligomers is difficult, the price for this type of quality is often 10–1000 fold that of polydisperse PEG.

PEGs are also available with different geometries.

* ''Branched'' PEGs have three to ten PEG chains emanating from a central core group.

* ''Star'' PEGs have 10 to 100 PEG chains emanating from a central core group.

* ''Comb'' PEGs have multiple PEG chains normally grafted onto a polymer backbone.

The numbers that are often included in the names of PEGs indicate their average molecular weights (e.g. a PEG with {{nowrap|''n'' {{=}} 9}} would have an average molecular weight of approximately 400 [[Atomic mass unit|daltons]], and would be labeled [[PEG 400]]). Most PEGs include molecules with a distribution of molecular weights (i.e. they are polydisperse). The size distribution can be characterized statistically by its [[weight average molecular weight]] (''M''_w) and its [[number average molecular weight]] (''M''_n), the ratio of which is called the [[polydispersity index]] (''Đ''_M). ''M''_w and ''M''_n can be measured by [[mass spectrometry]].

[[PEGylation]] is the act of covalently coupling a PEG structure to another larger molecule, for example, a [[therapeutic protein]], which is then referred to as a ''PEGylated'' protein. [[PEGylated interferon alfa-2a]] or [[PEGylated interferon alfa-2b|alfa-2b]] are commonly used injectable treatments for [[hepatitis C]] infection.

PEG is soluble in [[water]], [[methanol]], [[ethanol]], [[acetonitrile]], [[benzene]], and [[dichloromethane]], and is insoluble in [[diethyl ether]] and [[hexane]]. It is coupled to hydrophobic molecules to produce non-ionic [[surfactant]]s.<ref>{{cite journal|title=Force-field dependence of the conformational properties of α,ω-dimethoxypolyethylene glycol|journal=Molecular Physics|volume=107|issue=13|pages=1313–1321|doi=10.1080/00268970902794826|year=2009| vauthors = Winger M, De Vries AH, Van Gunsteren WF |bibcode=2009MolPh.107.1313W|hdl=10072/37876|s2cid=97215923|hdl-access=free}}</ref>

[[File:SArfus PEO.3D.jpg|thumb|right|Polyethylene oxide (PEO, [[molar mass distribution|M_w]] 4{{nbsp}}[[atomic mass unit|kDa]]) nanometric crystallites (4 nm)]]

PEG and related polymers (PEG phospholipid constructs) are often [[sonication|sonicated]] when used in biomedical applications. However, as reported by Murali et al., PEG is very sensitive to sonolytic degradation and PEG degradation products can be toxic to mammalian cells. It is, thus, imperative to assess potential PEG degradation to ensure that the final material does not contain undocumented contaminants that can introduce artifacts into experimental results.<ref>{{cite journal | vauthors = Murali VS, Wang R, Mikoryak CA, Pantano P, Draper R | title = Rapid detection of polyethylene glycol sonolysis upon functionalization of carbon nanomaterials | journal = Experimental Biology and Medicine | volume = 240 | issue = 9 | pages = 1147–51 | date = September 2015 | pmid = 25662826 | pmc = 4527952 | doi = 10.1177/1535370214567615 }}</ref>

PEGs and methoxypolyethylene glycols are manufactured by [[Dow Chemical Company|Dow Chemical]] under the trade name ''Carbowax'' for industrial use, and ''Carbowax Sentry'' for food and pharmaceutical use. They vary in consistency from liquid to solid, depending on the molecular weight, as indicated by a number following the name. They are used commercially in numerous applications, including foods, in [[cosmetics]], in pharmaceutics, in [[biomedicine]], as dispersing agents, as solvents, in [[ointment]]s, in [[suppository]] bases, as tablet [[excipient]]s, and as [[laxative]]s. Some specific groups are [[lauromacrogol]]s, [[nonoxynol]]s, [[octoxynol]]s, and [[poloxamer]]s.

==Production==

[[File:Polyethylene glycol 400.jpg|thumb|Polyethylene glycol 400, pharmaceutical quality]]

[[File:Polyethylene glycol 4000.jpg|thumb|Polyethylene glycol 4000, pharmaceutical quality]]

The production of polyethylene glycol was first reported in 1859. Both [[A. V. Lourenço]] and [[Charles Adolphe Wurtz]] independently isolated products that were polyethylene glycols.<ref name="Bailey">{{cite book| vauthors = Bailey FE, Koleske JV |title=Alkylene oxides and their polymers|date=1990|publisher=Dekker|location=New York|isbn=9780824783846|pages=27–28|url=https://books.google.com/books?id=LfmJuNNl5bwC&pg=PA27|access-date=17 July 2017}}</ref> Polyethylene glycol is produced by the interaction of [[ethylene oxide]] with water, [[ethylene glycol]], or ethylene glycol oligomers.<ref>[http://chemindustry.ru/Polyethylene_Glycol.php Polyethylene glycol], Chemindustry.ru</ref> The reaction is catalyzed by acidic or basic catalysts. Ethylene glycol and its oligomers are preferable as a starting material instead of water, because they allow the creation of polymers with a low [[polydispersity]] (narrow molecular weight distribution). Polymer chain length depends on the ratio of reactants.

:HOCH₂CH₂OH + n(CH₂CH₂O) → HO(CH₂CH₂O)_n+1H

Depending on the catalyst type, the mechanism of [[polymerization]] can be cationic or anionic. The anionic mechanism is preferable because it allows one to obtain PEG with a low [[polydispersity]]. Polymerization of ethylene oxide is an exothermic process. Overheating or contaminating ethylene oxide with catalysts such as alkalis or metal oxides can lead to runaway polymerization, which can end in an explosion after a few hours.

Polyethylene oxide, or high-molecular-weight polyethylene glycol, is synthesized by [[suspension polymerization]]. It is necessary to hold the growing polymer chain in [[polymer solution|solution]] in the course of the [[polycondensation]] process. The reaction is catalyzed by magnesium-, aluminium-, or calcium-organoelement compounds. To prevent [[coagulation]] of polymer chains from solution, chelating additives such as [[dimethylglyoxime]] are used.

Alkaline catalysts such as [[sodium hydroxide]] (NaOH), [[potassium hydroxide]] (KOH), or [[sodium carbonate]] (Na₂CO₃) are used to prepare low-molecular-weight polyethylene glycol.<ref>{{Cite web |title=PEG 4000, 6000, 8000, 12000 {{!}} Polyethylene glycol |url=https://www.venus-goa.com/Polyethylene-glycol.php |access-date=2023-01-19 |website=www.venus-goa.com |language=en}}</ref>

==Safety==

PEO's have "very low singledose oral toxicity", on the order of tens of grams per kg body weight (oral).<ref name=Ullmann/> Because of its low toxicity, PEO is used in a variety of edible products.<ref>{{cite book|vauthors = Sheftel VO|title = Indirect Food Additives and Polymers: Migration and Toxicology|year = 2000|pages = 1114–1116|publisher = CRC|url = http://www.mindfully.org/Plastic/Polymers/Polyethylene-Glycols-PEGs.htm|access-date = 22 August 2007|archive-date = 9 August 2007|archive-url = https://web.archive.org/web/20070809043819/http://www.mindfully.org/Plastic/Polymers/Polyethylene-Glycols-PEGs.htm|url-status = dead}}</ref> The polymer is used as a lubricating coating for various surfaces in aqueous and non-aqueous environments.<ref>{{cite journal | vauthors = Nalam PC, Clasohm JN, Mashaghi A, Spencer ND |doi=10.1007/s11249-009-9549-9|title=Macrotribological Studies of Poly(L-lysine)-graft-Poly(ethylene glycol) in Aqueous Glycerol Mixtures|year=2009 |s2cid=109928127|journal=Tribology Letters|volume=37|issue=3|pages=541–552|hdl=20.500.11850/17055|url=http://doc.rero.ch/record/314245/files/11249_2009_Article_9549.pdf|type=Submitted manuscript|hdl-access=free}}</ref>

The precursor to PEGs is [[ethylene oxide]], which is hazardous.<ref>{{Cite web|url=https://www.fda.gov/cosmetics/productsingredients/potentialcontaminants/ucm101566.htm|title=Potential Contaminants - 1,4-Dioxane A Manufacturing Byproduct | author = Center for Food Safety and Applied Nutrition |website=fda.gov|language=en|access-date=2017-05-26}}</ref> Ethylene glycol and its ethers are [[Nephrotoxicity|nephrotoxic]] if applied to damaged skin.<ref name="ReferenceA">{{Cite journal | title = Special Report: Reproductive and Developmental Toxicity of Ethylene Glycol and Its Ethers| journal = International Journal of Toxicology | volume = 18 | issue = 3 | pages = 53–67| year = 1999 | doi = 10.1177/109158189901800208 | vauthors = Andersen FA | s2cid = 86231595 | doi-access = free }}</ref>

== See also ==

* [[Ethylene]]

* [[Propylene glycol]]

* [[Monoethylene glycol]]

* [[Diethylene glycol]]

* [[PEGylation]]

* [[PEG-PVA]]

* [[Lauryl methyl gluceth-10 hydroxypropyl dimonium chloride]]

* [[Movicol]]

* [[Polyethylene glycol propylene glycol cocoates]]

*[[Lysozyme PEGylation]]

== References ==

{{Reflist}}

== External links ==

{{Commons category|Poly(ethylene glycol)}}

{{Commons category|Polyethylene glycols}}

* [http://owic.oregonstate.edu/sites/default/files/pubs/peg.pdf Oregon State University informational paper on using PEG as a wood stabilizer]

{{Laxatives}}

{{DEFAULTSORT:Polyethylene Glycol}}

[[Category:Biomaterials]]

[[Category:Coolants]]

[[Category:Excipients]]

[[Category:Laxatives]]

[[Category:Polyethers]]

[[Category:Polymers]]

[[Category:Ether solvents]]

[[Category:E-number additives]]

[[Category:Allergology]]