Editing Polytetrafluoroethylene (section)

== Production ==
PTFE is produced by [[free-radical]] [[polymerization]] of [[tetrafluoroethylene]].<ref>{{cite journal |last1=Puts |first1=Gerard J. |last2=Crouse |first2=Philip |last3=Ameduri |first3=Bruno M. |title=Polytetrafluoroethylene: Synthesis and Characterization of the Original Extreme Polymer |journal=Chemical Reviews |date=28 January 2019 |doi=10.1021/acs.chemrev.8b00458 |volume=119 |issue=3 |pages=1763–1805|pmid=30689365 |s2cid=59338589 |hdl=2263/68582 |hdl-access=free }}</ref> The net equation is as follows:
: ''n'' F<sub>2</sub>C=CF<sub>2</sub> → −(F<sub>2</sub>C−CF<sub>2</sub>)<sub>''n''</sub>−
Because tetrafluoroethylene can explosively decompose to [[tetrafluoromethane]] ({{chem2|CF4}}) and carbon, a special apparatus is required for the polymerization to prevent hot spots that might initiate this dangerous side reaction. The process is typically initiated with [[Peroxydisulfate|persulfate]], which [[Homolysis (chemistry)|homolyzes]] to generate sulfate radicals:
: [O<sub>3</sub>SO−OSO<sub>3</sub>]<sup>2−</sup> ⇌ 2 {{chem|SO|4|•−}}
The resulting polymer is terminated with [[sulfate ester]] groups, which can be [[hydrolyzed]] to give OH [[end-group]]s.<ref name=Ullmann>Carlson, D. Peter and Schmiegel, Walter (2000) "Fluoropolymers, Organic" in ''Ullmann's Encyclopedia of Industrial Chemistry'', Wiley-VCH, Weinheim. {{doi|10.1002/14356007.a11_393}}</ref>

Granular PTFE is produced via [[suspension polymerization]], where PTFE is suspended in an [[Aqueous solution|aqueous]] medium primarily via agitation and sometimes with the use of a [[surfactant]]. PTFE is also synthesized via [[emulsion polymerization]], where a surfactant is the primary means of keeping PTFE in an aqueous medium.<ref>{{cite book |doi=10.1016/B978-1-4557-7442-5.00007-3 |chapter=Manufacturing Polytetrafluoroethylene |title=Introduction to Fluoropolymers |date=2013 |pages=91–124 |isbn=978-1-4557-7442-5 }}</ref> Surfactants in the past have included [[perfluorooctanoic acid]] (PFOA) and [[perfluorooctanesulfonic acid]] (PFOS). More recently, Perfluoro 3,6 dioxaoctanoic acid (PFO2OA) and [[FRD-903]] (GenX) are being used as alternatives.<ref>{{cite journal |last1=Pierozan |first1=Paula |last2=Cattani |first2=Daiane |last3=Karlsson |first3=Oskar |title=Tumorigenic activity of alternative per- and polyfluoroalkyl substances (PFAS): Mechanistic in vitro studies |journal=Science of the Total Environment |date=February 2022 |volume=808 |pages=151945 |doi=10.1016/j.scitotenv.2021.151945 |pmid=34843762 |bibcode=2022ScTEn.80851945P |s2cid=244730906 |doi-access=free }}</ref>