Editing Polyoxymethylene (section)

==Development==
Polyoxymethylene was discovered by [[Hermann Staudinger]], a German chemist who received the 1953 [[Nobel Prize in Chemistry]].<ref name="Nobel">{{cite web|title=The Nobel Prize in Chemistry 1953|url=https://www.nobelprize.org/nobel_prizes/chemistry/laureates/1953/|website=NobelPrize.org|access-date=8 March 2016}}</ref> He had studied the [[polymerization]] and structure of POM in the 1920s while researching [[macromolecules]], which he characterized as polymers. Due to problems with [[thermostability]], POM was not commercialized at that time.<ref>{{Cite web |last=Kincaid |first=Courtney |date=2018-07-06 |title=Acetal - Polyoxymethylene (POM) - Thermoplastic |url=https://www.polymershapes.com/acetal/ |access-date=2024-05-13 |website=Polymershapes |language=en-US}}</ref>

Circa 1952, research chemists at [[DuPont]] synthesized a version of POM,<ref name="KennedyWatkins2012">{{cite book|author1=Joseph P. Kennedy|author2=Wayne H. Watkins|title=How to Invent and Protect Your Invention: A Guide to Patents for Scientists and Engineers|url=https://books.google.com/books?id=SxxXvUv3jH8C&pg=PT194|date=31 July 2012|publisher=John Wiley & Sons|isbn=978-1-118-41009-7|pages=194–}}</ref> and in 1956 the company filed for patent protection of the [[homopolymer]],<ref name="BPF-timeline">{{cite web|title=A History of Plastics|url=http://www.bpf.co.uk/plastipedia/plastics_history/default.aspx|website=British Plastics Federation|access-date=8 March 2016}}</ref> forgetting to mention in the patent the term [[copolymer]], opening thus the road to competitors. DuPont credits R. N. MacDonald as the inventor of high-molecular-weight POM.<ref>[http://uk.news.dupont.com/site/contenu.asp?idtri=624&idcontenu=56221 News & Media Relations Home - DuPont EMEA<!-- Bot generated title -->]{{Dead link|date=November 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> Patents by MacDonald and coworkers describe the preparation of high-molecular-weight [[hemiacetal]]-terminated (~O−CH<sub>2</sub>OH) POM,<ref>{{cite patent|country=US|number=2768994|pubdate=1956-10-30|title=Polyoxymethylenes|assign1=[[DuPont|E. I. Du Pont de Nemours and Co.]]|inventor1-last=Macdonald|inventor1-first=Robert Neal}}</ref> but these lack sufficient thermal stability to be  commercially viable. The inventor of a heat-stable (and therefore useful) POM homopolymer was Stephen Dal Nogare,<ref>{{Cite patent|country=US|number=2998409|pubdate=1961-08-29|title=Polyoxymethylene carboxylates of improved thermal stability|assign1=[[DuPont|E. I. Du Pont de Nemours and Co.]]|inventor1-last=Nogare|inventor1-first=Stephen Dal|inventor2-last=Punderson|inventor2-first=John Oliver}}</ref> who discovered that reacting the hemiacetal ends with [[acetic anhydride]] converts the readily depolymerizable hemiacetal into a thermally stable, melt-processable plastic.

In 1960, DuPont completed construction of a plant to produce its own version of acetal resin, named ''Delrin'', at [[Parkersburg, West Virginia|Parkersburg, United States]].<ref name="PainterColeman2008">{{cite book|author1=Paul C. Painter|author2=Michael M. Coleman|title=Essentials of Polymer Science and Engineering|url=https://books.google.com/books?id=CL7O_hH0aw4C&pg=PA313|year=2008|publisher=DEStech Publications, Inc|isbn=978-1-932078-75-6|pages=313–}}</ref> Also in 1960, [[Celanese]] completed its own research. Shortly thereafter, in  a limited partnership with the [[Frankfurt]] firm [[Hoechst AG]], a factory was built in [[Kelsterbach]], [[Hessen]]; from there, ''Celcon'' was produced starting in 1962,<ref name="Ibeh2011">{{cite book|author=Christopher C. Ibeh|title=Thermoplastic Materials: Properties, Manufacturing Methods, and Applications|url=https://books.google.com/books?id=qwfMBQAAQBAJ&pg=PA473|date=25 April 2011|publisher=CRC Press|isbn=978-1-4200-9384-1|pages=473–}}</ref> with ''Hostaform'' joining it a year later. Both remain in production under the auspices of [[Celanese]] and are sold as parts of a product group now called 'Hostaform/Celcon POM''.