Editing Nylon

{{short description|Early synthetic polymer developed as a textile fibre}}
{{Other uses}}
{{Use British English|date=December 2018}}
{|style="border: 1px solid; float: right; width: 250px;"
!colspan="2" style="text-align: center;"| Nylon 6 [[Image:Nylon 6 and Nylon 6-6.svg|320px|Nylon]] Nylon 6,6
|-
|[[Density]]
|1.15&nbsp;g/cm<sup>3</sup>
|- style="background:#eee;"
|[[Electrical conductivity]] (σ)
|10<sup>−12</sup>&nbsp;[[siemens (unit)|S]]/m
|-
|[[Thermal conductivity]]
|0.25&nbsp;[[Watt|W]]/(m·[[Kelvin|K]])
|- style="background:#eee;"
|[[Melting point]]
|463–624 [[Kelvin|K]]<br/> 190–350 °[[Celsius|C]]<br/> 374–663 °[[Fahrenheit|F]]
|}

'''Nylon''' is a family of [[synthetic polymer]]s characterised by [[amide]] linkages, typically connecting [[aliphatic]] or [[Polyamide#Classification|semi-aromatic]] groups.

Nylons are generally brownish in color<ref>{{Cite book |last=Muccio |first=Edward A. |url=https://books.google.com/books?id=0uuo7J855Z0C&dq=nylon+color&pg=PA38 |title=Plastics Processing Technology |date=1994-01-01 |publisher=ASM International |isbn=978-1-61503-212-9 |pages=38 |language=en}}</ref> and can possess a soft texture, with some varieties exhibiting a [[silk]]-like appearance.<ref>{{Cite book |url=https://books.google.com/books?id=RiM4plecZw0C&dq=nylon+texture&pg=PA65 |title=Salters Higher Chemistry |date=1999 |publisher=Heinemann |isbn=978-0-435-63098-0 |pages=65 |language=en}}</ref> As [[Thermoplastic|thermoplastics]], nylons can be melt-processed into fibres, [[Thin film|films]], and diverse shapes.<ref name="Vogler">{{cite journal|last1=Vogler|first1=H.|year=2013|title=Wettstreit um die Polyamidfasern|journal=Chemie in unserer Zeit|volume=47|issue=1 |pages=62–63|doi=10.1002/ciuz.201390006}}</ref><ref name="AOGHS" /><ref name="Kohan">{{cite book|title=Nylon Plastics Handbook|last1=Kohan|first1=Melvin|date=1995|publisher=Carl Hanser Verlag|isbn=1569901899|location=Munich}}</ref>{{rp|2}} The properties of nylons are often modified by blending with a variety of additives.

Numerous types of nylon are available. One family, designated nylon-XY, is derived from [[diamine]]s and [[dicarboxylic acid]]s of carbon chain lengths X and Y, respectively. An important example is nylon-6,6 ({{chem2|(\sC(O)(CH2)4C(O)\sNH(CH2)6NH\s)_{n}|}}). Another family, designated nylon-Z, is derived from [[amino acid|aminocarboxylic acid]]s with carbon chain length Z. An example is nylon-[6].

Nylon polymers have extensive commercial applications, including uses in [[textiles]] and fibres (such as apparel, flooring and rubber reinforcement), molded components for automotive and electrical equipment, and films (mostly for [[food packaging]]).<ref name="BPF">{{cite web|title=Nylons (Polyamide)|url=http://www.bpf.co.uk/plastipedia/polymers/polyamides.aspx|website=British Plastics Federation|access-date=19 June 2017}}</ref>

== History ==
[[File:Wallace Carothers, in the lab.jpg|thumb|upright|Wallace Carothers]]

=== DuPont and the invention of nylon ===
Researchers at [[DuPont]] began developing cellulose-based fibres, culminating in the synthetic fibre [[rayon]]. DuPont's experience with rayon was an important precursor to its development and marketing of nylon.<ref name="Ndiaye">{{cite book|url=https://books.google.com/books?id=PHH3iE2LPCoC&pg=PA236|title=Nylon and bombs : DuPont and the march of modern America|last1=Ndiaye|first1=Pap A.|last2=Forster|first2=Elborg|date=2007|publisher=Johns Hopkins University Press|isbn=9780801884443|location=Baltimore|pages=182|access-date=19 June 2017}}</ref>{{rp|8,64,236}}

DuPont's invention of nylon spanned an eleven-year period, ranging from the initial research program in polymers in 1927 to its announcement in 1938, shortly before the opening of the [[1939 New York World's Fair]].<ref name=":1">{{Cite book|title=Nylon: A DuPont Invention|last=DuPont|publisher=DuPont International, Public Affairs|year=1988|pages=2–3}}</ref> The project grew from a new organisational structure at DuPont, suggested by [[Charles Stine]] in 1927, in which the chemical department would be composed of several small research teams that would focus on "pioneering research" in chemistry and would "lead to practical applications".<ref name="Ndiaye" />{{rp|92}} Harvard instructor [[Wallace Hume Carothers]] was hired to direct the polymer research group. Initially he was allowed to focus on pure research, building on and testing the theories of German chemist [[Hermann Staudinger]].<ref name="Kativa"/> He was very successful, as research he undertook greatly improved the knowledge of polymers and contributed to the science.<ref name="Meikle">{{cite book|last1=Meikle|first1=Jeffrey L.|title=American plastic: A cultural history|date=1995|publisher=Rutgers University Press|location=New Brunswick, NJ|isbn=0813522358|edition=1. ppb. print|url=https://books.google.com/books?id=u_1ePU4GEGAC&pg=PA1927}}</ref>

Nylon was the first commercially successful synthetic [[thermoplastic]] polymer.<ref name="PlasticsCHF">{{cite web|url=https://www.sciencehistory.org/science-of-plastics|title=Science of Plastics|website=[[Science History Institute]]|date=2016-07-18|access-date=26 March 2018}}</ref> DuPont began its research project in 1927.<ref name=":1" />
The first nylon, [[nylon 66]], was synthesised on February 28, 1935, by Wallace Hume Carothers at DuPont's research facility at the [[DuPont Experimental Station]].<ref name="ACS">{{cite web|last1=American Chemical Society National Historic Chemical Landmarks|title=Foundations of Polymer Science: Wallace Hume Carothers and the Development of Nylon|url=http://www.acs.org/content/acs/en/education/whatischemistry/landmarks/carotherspolymers.html|website=ACS Chemistry for Life|access-date=27 January 2015}}</ref><ref name="Carothers">{{cite web|title=Wallace Hume Carothers|url=https://www.sciencehistory.org/historical-profile/wallace-hume-carothers|website=[[Science History Institute]]|date=June 2016|access-date=20 March 2018}}</ref> In response to Carothers' work, [[Paul Schlack]] at [[IG Farben]] developed [[nylon 6|nylon&nbsp;6]], a different molecule based on [[caprolactam]], on January 29, 1938.<ref name="McIntyre">{{cite book|last1=McIntyre|first1=J. E.|title=Synthetic fibres: nylon, polyester, acrylic, polyolefin|date=2005|publisher=Woodhead|location=Cambridge |isbn=9780849325922|page=10|edition=1st|url=https://books.google.com/books?id=zpMw7kB3EWQC&pg=PA10|access-date=5 July 2017}}</ref>{{rp|10}}<ref name="Travis">{{cite book|last1=Travis|first1=Anthony S.|title=Determinants in the evolution of the European chemical industry: 1900-1939: new technologies, political frameworks, markets and companies|date=1998|publisher=Kluwer Acad. Publ.|location=Dordrecht|isbn=9780792348900|page=115|url=https://books.google.com/books?id=gvP7CAAAQBAJ&pg=PA115|access-date=5 July 2017}}</ref>

In the spring of 1930, Carothers and his team had already synthesised two new polymers. One was [[neoprene]], a synthetic rubber greatly used during World War II.<ref>{{Cite web|url=https://chlorine.americanchemistry.com/Science-Center/Chlorine-Compound-of-the-Month-Library/Neoprene-The-First-Synthetic-Rubber/|title=Neoprene: The First Synthetic Rubber|website=chlorine.americanchemistry.com|access-date=2018-12-06|archive-date=2020-09-26|archive-url=https://web.archive.org/web/20200926141526/https://chlorine.americanchemistry.com/Science-Center/Chlorine-Compound-of-the-Month-Library/Neoprene-The-First-Synthetic-Rubber/|url-status=dead}}</ref> The other was a white elastic but strong paste that would later become nylon. After these discoveries, Carothers' team was made to shift its research from a more pure research approach investigating general polymerisation to a more practically focused goal of finding "one chemical combination that would lend itself to industrial applications".<ref name="Ndiaye" />{{rp|94}}

It was not until the beginning of 1935 that a polymer called "polymer 6-6" was finally produced. Carothers' coworker, [[Washington University in St. Louis|Washington University]] alumnus [[Julian W. Hill]] had used a [[Drawing (manufacturing)#Plastic drawing|cold drawing]] method to produce a [[polyester]] in 1930.<ref>{{Cite web|url=https://www.acs.org/content/acs/en/education/whatischemistry/landmarks/carotherspolymers.html|title=Wallace Carothers and the Development of Nylon - Landmark|website=American Chemical Society|language=en|access-date=2019-08-14}}</ref> This cold drawing method was later used by Carothers in 1935 to fully develop nylon.<ref>{{Cite news|url=https://www.nytimes.com/1996/02/01/us/julian-w-hill-nylon-s-discoverer-dies-at-91.html|title=Julian W. Hill, Nylon's Discoverer, Dies at 91|last=Stout|first=David|date=1996-02-01|work=The New York Times|access-date=2019-08-14|language=en-US|issn=0362-4331}}</ref> The first example of nylon (nylon 6.6) was produced on February 28, 1935, at DuPont's research facility at the DuPont Experimental Station.<ref name=ACS/> It had all the desired properties of elasticity and strength. However, it also required a complex manufacturing process that would become the basis of industrial production in the future. DuPont obtained a patent for the polymer in September 1938,<ref name="US 2130523"/> and quickly achieved a monopoly of the fibre.<ref name="Meikle" /> Carothers died 16 months before the announcement of nylon, therefore he was never able to see his success.<ref name=":1" /> The name "Nylon" came from the a modification of ''norun'' (no run) into a unique name that could be used to market the product but was not trademarked.<ref name="Myers">{{Cite book|last=Myers|first=Richard L.|url=https://books.google.com/books?id=0AnJU-hralEC|title=The 100 Most Important Chemical Compounds: A Reference Guide|date=2007|publisher=ABC-CLIO|isbn=978-0-313-33758-1|language=en|pages=20–23|access-date=21 November 2015|archive-date=17 June 2016|archive-url=https://web.archive.org/web/20160617093705/https://books.google.com/books?id=0AnJU-hralEC|url-status=live}}</ref>

Nylon was first used commercially in a nylon-[[bristle]]d [[toothbrush]] in 1938,<ref name="AOGHS"/><ref name="Nicholson">{{cite magazine|last1=Nicholson|first1=Joseph L.|last2=Leighton|first2=George R.|title=Plastics Come of Age|url=https://archive.org/stream/harpersmagazine185junalde/harpersmagazine185junalde_djvu.txt|access-date=5 July 2017|magazine=Harper's Magazine|pages=300–307|date=August 1942}}</ref> followed more famously in women's [[stocking]]s or "nylons" which were shown at the 1939 New York World's Fair and first sold commercially in 1940,<ref name="Wolfe2008">{{cite journal|date=October 3, 2008 |title=Nylon: A Revolution in Textiles|url=https://www.sciencehistory.org/distillations/magazine/nylon-a-revolution-in-textiles|journal=Distillations Magazine |publisher=Science History Institute |last1=Wolfe|first1=Audra J.|access-date=20 March 2018 |url-status=live |archive-url= https://web.archive.org/web/20180321130329/https://www.sciencehistory.org/distillations/magazine/nylon-a-revolution-in-textiles |archive-date= March 21, 2018  }}</ref> whereupon they became an instant commercial success with 64 million pairs sold during their first year on the market. During World War II, almost all nylon production was diverted to the military for use in [[parachutes]] and [[parachute cord]]. Wartime uses of nylon and other [[plastics]] greatly increased the market for the new materials.<ref name="Conflicts">{{cite web|title=The History and Future of Plastics|url=https://www.sciencehistory.org/the-history-and-future-of-plastics|work=Conflicts in Chemistry: The Case of Plastics |publisher=Science History Institute |access-date=20 March 2018 |url-status=live |archive-url=https://web.archive.org/web/20180320170600/https://www.sciencehistory.org/the-history-and-future-of-plastics |archive-date=20 March 2018 }}</ref>

The production of nylon required interdepartmental collaboration between three departments at DuPont: the Department of Chemical Research, the Ammonia Department, and the Department of Rayon.<ref>{{Cite book |title=Nylon and Bombs: DuPont and the March of Modern America |isbn=9781421403342 |date=2007 |url=https://dokumen.pub/nylon-and-bombs-dupont-and-the-march-of-modern-america-9781421403342-9780801884443.html |access-date=2022-08-08 |website=Dokumen.PUB |language=en |url-status=live |archive-url=https://web.archive.org/web/20220808110540/https://dokumen.pub/nylon-and-bombs-dupont-and-the-march-of-modern-america-9781421403342-9780801884443.html |archive-date=2022-08-08 |last1=Ndiaye |first1=Pap A. |publisher=Johns Hopkins University Press+ORM }}</ref> Some of the key ingredients of nylon had to be produced using [[high pressure chemistry]], the main area of expertise of the Ammonia Department. Nylon was considered a "godsend to the Ammonia Department",<ref name="Ndiaye" /> which had been in financial difficulties. The reactants of nylon soon constituted half of the Ammonia Department's sales and helped them come out of the period of the [[Great Depression]] by creating jobs and revenue at DuPont.<ref name="Ndiaye" />

DuPont's nylon project demonstrated the importance of [[chemical engineering]] in industry, helped create jobs, and furthered the advancement of chemical engineering techniques. In fact, it developed a chemical plant that provided 1800 jobs and used the latest technologies of the time, which are still used as a model for chemical plants today.<ref name="Ndiaye" /> The ability to acquire a large number of chemists and engineers quickly was a huge contribution to the success of DuPont's nylon project.<ref name="Ndiaye" />{{rp|100–101}} The first nylon plant was located at Seaford, Delaware, beginning commercial production on December 15, 1939. On October 26, 1995, the Seaford plant was designated a [[National Historic Chemical Landmark]] by the [[American Chemical Society]].<ref name="Landmark">{{cite web|title=A National Historic Chemical Landmark: The First Nylon Plant|url=https://www.acs.org/content/dam/acsorg/education/whatischemistry/landmarks/carotherspolymers/first-nylon-plant-historical-resource.pdf |first1=John F. |last1=McAllister |date=Oct 26, 1995 |website=American Chemical Society|access-date=26 June 2017}}</ref>

=== Early marketing strategies ===

An important part of nylon's popularity stems from DuPont's marketing strategy. DuPont promoted the fibre to increase demand before the product was available to the general market. Nylon's commercial announcement occurred on October 27, 1938, at the final session of the ''[[New York Herald Tribune|Herald Tribune]]''{{'}}s yearly "Forum on Current Problems", on the site of the approaching New York City world's fair.<ref name="Kativa">{{cite journal|last1=Kativa|first1=Hillary|title=Synthetic Threads|journal=Distillations|date=2016|volume=2|issue=3|pages=16–21|url=https://www.sciencehistory.org/distillations/magazine/synthetic-threads|access-date=20 March 2018}}</ref><ref name="Meikle" />{{rp|141}} The "first man-made organic textile fibre" which was derived from "coal, water and air" and promised to be "as strong as steel, as fine as the spider's web" was received enthusiastically by the audience, many of them middle-class women, and made the headlines of most newspapers.<ref name="Meikle" />{{rp|141}} Nylon was introduced as part of "The world of tomorrow" at the 1939 New York World's Fair<ref name="Blakinger">{{cite news|last1=Blakinger|first1=Keri |title=A look back at some of the coolest attractions at the 1939 World's Fair|url=http://www.nydailynews.com/new-york/queens/back-attractions-1939-world-fair-article-1.2619155|access-date=20 June 2017|work=New York Daily News|date=April 30, 2016 |url-status=live |archive-url= https://web.archive.org/web/20170912053601/http://www.nydailynews.com/new-york/queens/back-attractions-1939-world-fair-article-1.2619155 |archive-date= Sep 12, 2017 }}</ref> and was featured at DuPont's "Wonder World of Chemistry" at the [[Golden Gate International Exposition]] in San Francisco in 1939.<ref name="Kativa"/><ref name="Sundberg">{{cite book|last1=Sundberg|first1=Richard J.|title=The Chemical Century: Molecular Manipulation and Its Impact on the 20th Century|date=2017|publisher=Apple Academic Press, Incorporated|isbn=9781771883665|url=https://books.google.com/books?id=D9eRDgAAQBAJ&pg=PT216}}</ref> Actual [[Fully fashioned stockings|nylon stockings]] were not shipped to selected stores in the national market until May 15, 1940. However, a limited number were released for sale in Delaware before that.<ref name="Meikle" />{{rp|145–146}} The first public sale of nylon stockings occurred on October 24, 1939, in Wilmington, Delaware. 4,000 pairs of stockings were available, all of which were sold within three hours.<ref name="Kativa"/>

Another added bonus to the campaign was that it meant reducing silk imports from Japan, an argument that won over many wary customers. Nylon was even mentioned by [[Franklin D. Roosevelt|President Roosevelt]]'s cabinet, which addressed its "vast and interesting economic possibilities" five days after the material was formally announced.<ref name="Meikle" />

However, the early excitement over nylon also caused problems. It fueled unreasonable expectations that nylon would be better than silk, a miracle fabric as strong as steel that would last forever and never run.<ref name="Meikle" />{{rp|145–147}}<ref name="Wolfe2008"/> Realizing the danger of claims such as "New Hosiery Held Strong as Steel" and "No More Runs", DuPont scaled back the terms of the original announcement, especially those stating that nylon would possess the strength of steel.<ref name="Meikle" />

Also, DuPont executives marketing nylon as a revolutionary man-made material did not at first realise that some consumers experienced a sense of unease and distrust, even fear, towards synthetic fabrics.<ref name="Meikle" />{{rp|126–128}} A particularly damaging news story, drawing on DuPont's 1938 patent for the new polymer, suggested that one method of producing nylon might be to use [[cadaverine]] (pentamethylenediamine),{{efn|Actually the most common nylon polymers are made from hexamethylenediamine, with one more CH<sub>2</sub> group than cadaverine.}} a chemical extracted from corpses. Although scientists asserted that cadaverine was also extracted by heating coal, the public often refused to listen. A woman confronted one of the lead scientists at DuPont and refused to accept that the rumour was not true.<ref name="Meikle" />{{rp|146–147}}

DuPont changed its campaign strategy, emphasizing that nylon was made from "coal, air and water", and started focusing on the personal and aesthetic aspects of nylon, rather than its intrinsic qualities.<ref name="Meikle" />{{rp|146–147}} Nylon was thus domesticated,<ref name="Meikle"/>{{rp|151–152}} and attention shifted to the material and consumer aspect of the fibre with slogans like "If it's nylon, it's prettier, and oh! How fast it dries!".<ref name="Ndiaye" />{{rp|2}}

=== Production of nylon fabric ===
[[File:NMA.0028271, Fashion Photo by Erik Liljeroth 1954.jpg|thumb|upright|Nylon stockings being inspected in [[Malmö]], Sweden, in 1954]]

After nylon's nationwide release in 1940, its production ramped up significantly. In that year alone, 1300 tons of the fabric were produced, marking a remarkable start for this innovative material.[8]: 100  The demand for nylon surged, particularly for nylon stockings, which became an instant sensation. During their first year on the market, an astounding 64 million pairs of nylon stockings were sold, reflecting the fabric's rapid integration into daily life and fashion.[8]: 101  Such was the success of nylon that in 1941, just a year after its launch, a second plant was opened in Martinsville, Virginia, to meet the growing demand and ensure a steady supply of this popular fabric. This expansion underscored the profound impact nylon had on the textile industry and its rapid rise to prominence as a versatile and sought-after material.<ref name=":0">{{Cite book|title=It Happened in Delaware|last=Colbert|first=Judy|publisher=Rowman & Littlefield|year=2013|isbn=978-0-7627-9577-2|pages=60}}</ref>

[[File:Particolare di calza di nylon.jpg|left|thumb|Close-up photograph of the knitted nylon fabric used in stockings]]

[[File:Nylon fibre SEM.tif|left|thumb|Nylon fibres visualised using [[scanning electron microscopy]]]]

While nylon was marketed as the durable and indestructible material of the people, it was sold at about one-and-a-half times the price of [[silk]] stockings ($4.27 per pound of nylon versus $2.79 per pound of silk).<ref name="Ndiaye" />{{rp|101}} Sales of nylon stockings were strong in part due to changes in women's fashion. As Lauren Olds explains: "by 1939 [hemlines] had inched back up to the knee, closing the decade just as it started off". The shorter skirts were accompanied by a demand for stockings that offered fuller coverage without the use of garters to hold them up.<ref name="Olds">{{cite journal|last1=Olds|first1=Lauren|title=World War II and Fashion: The Birth of the New Look|journal=Constructing the Past|date=2001|volume=2|issue=1|page=Article 6|url=http://digitalcommons.iwu.edu/cgi/viewcontent.cgi?article=1062&context=constructing|access-date=19 June 2017}}</ref>

However, as of February 11, 1942, nylon production was redirected from being a consumer material to one used by the military.<ref name="Kativa" /> DuPont's production of nylon stockings and other lingerie stopped, and most manufactured nylon was used to make parachutes and tents for [[World War II]].<ref name="Krier">{{Cite news|url=https://www.latimes.com/archives/la-xpm-1988-10-27-vw-227-story.html|title=How Nylon Changed the World : 50 Years Ago Today, It Reshaped the Way We Live--and Think|last=Krier|first=Beth Ann|date=27 October 1988|newspaper=Los Angeles Times}}</ref> Although nylon stockings already made before the war could be purchased, they were generally sold on the black market for as high as $20.<ref name=":0" />

Once the war ended, the return of nylon was awaited with great anticipation. Although DuPont projected yearly production of 360 million pairs of stockings, there were delays in converting back to consumer rather than wartime production.<ref name="Kativa" /> In 1946, the demand for nylon stockings could not be satisfied, which led to the [[nylon riots]]. In one instance, an estimated 40,000 people lined up in Pittsburgh to buy 13,000 pairs of nylons.<ref name="Wolfe2008"/> In the meantime, women cut up nylon tents and parachutes left from the war in order to make blouses and wedding dresses.<ref>{{cite web|title=Parachute Wedding Dress, 1947|url=http://newsdesk.si.edu/snapshot/parachute-wedding-dress|website=Smithsonian National Museum of American History|access-date=20 June 2017}}</ref><ref>{{cite journal|journal=Woman's Home Companion|date=1948|publisher=Crowell-Collier Publishing Company|volume=75|page=155}}</ref> Between the end of the war and 1952, production of stockings and lingerie used 80% of the world's nylon. DuPont put focus on catering to the civilian demand, and continually expanded its production.

=== Introduction of nylon blends ===

As pure nylon hosiery was sold in a wider market, problems became apparent. Nylon stockings were found to be fragile, in the sense that the thread often tended to unravel lengthwise, creating 'runs'.<ref name="Ndiaye" />{{rp|101}} People also reported that pure nylon textiles could be uncomfortable due to nylon's lack of absorbency.<ref>{{cite book|author=Reader's Digest|title=New complete guide to sewing: step-by-step techniques for making clothes and home accessories|date=2002|publisher=Reader's Digest|location=London|page=19|isbn=9780762104208|url=https://books.google.com/books?id=v1ZVvZTdZRMC&pg=PA19|access-date=26 June 2017}}</ref> Moisture stayed inside the fabric near the skin under hot or moist conditions instead of being "wicked" away.<ref>{{cite journal|title=How to buy a trail bed|url=https://books.google.com/books?id=_98DAAAAMBAJ&pg=PA70|access-date=26 June 2017|journal=Backpacker|volume=5|number=3|page=70|date=June 1977}}</ref> Nylon fabric could also be itchy and tended to cling and sometimes spark as a result of static electrical charge built up by friction.<ref name="Mendelson">{{cite book|last1=Mendelson|first1=Cheryl|title=Home comforts : the art and science of keeping house|date=2005|publisher=Scribner|location=New York|isbn=978-0743272865|url=https://archive.org/details/homecomfortsarts0000mend|url-access=registration|page=[https://archive.org/details/homecomfortsarts0000mend/page/224 224]|access-date=26 June 2017}}</ref><ref name="Shaeffer">{{cite book|last1=Shaeffer|first1=Claire|title=Claire Shaeffer's fabric sewing guide.|date=2008|publisher=Krause Publications|location=Cincinnati, Ohio|isbn=978-0896895362|pages=[https://archive.org/details/claireshaeffersf0000shae/page/88 88]–90|edition=2nd|url=https://archive.org/details/claireshaeffersf0000shae|url-access=registration}}</ref> Also, under some conditions, nylon could degrade, perforating or shredding stockings.<ref name="Meikle"/>{{rp|p=147}} Scientists explained this as [[Polymer degradation#Hydrolysis|acid hydrolysis]] resulting from [[air pollution]], attributing it to London smog in 1952, as well as poor air quality in New York and Los Angeles.<ref name="Cheremisinoff">{{cite book|last1=Cheremisinoff|first1=Nicholas P.|title=Handbook of air pollution prevention and control|url=https://archive.org/details/handbookairpollu00cher_913|url-access=limited|date=2002|publisher=Butterworth-Heinemann|location=Amsterdam|isbn=9780080507927|page=[https://archive.org/details/handbookairpollu00cher_913/page/n79 65]}}</ref><ref name="Stern">{{cite book|editor-last1=Stern|editor-first1=Arthur C.|title=Air pollution and its effects|date=1970|publisher=Academic press|location=New York|isbn=978-0-12-666551-2|page=72|edition=2nd|url=https://books.google.com/books?id=07FA4WIBkf8C&pg=PA72|access-date=26 June 2017}}</ref><ref name="Garte">{{cite book|last1=Garte|first1=Seymour|title=Where we stand : a surprising look at the real state of our planet|date=2008|publisher=AMACOM|location=New York|isbn=978-0814409107|page=[https://archive.org/details/wherewestandsurp0000gart/page/60 60]|url=https://archive.org/details/wherewestandsurp0000gart|url-access=registration|access-date=26 June 2017}}</ref><ref>{{cite journal |last1=Campbell |first1=Dean J. |last2=Wright |first2=Emily A. |last3=Dayisi |first3=Mardhia O. |last4=Hoehn |first4=Michael R. |last5=Kennedy |first5=Branden F. |last6=Maxfield |first6=Brian M. |title=Classroom Illustrations of Acidic Air Pollution Using Nylon Fabric |journal=Journal of Chemical Education |date=1 April 2011 |volume=88 |issue=4 |pages=387–391 |doi=10.1021/ed100604a|bibcode=2011JChEd..88..387C }}</ref>

The solution found to problems with pure nylon fabric was to blend nylon with other existing fibres or polymers such as [[cotton]], [[polyester]], and [[spandex]]. This led to the development of a wide array of blended fabrics. The new nylon blends retained the desirable properties of nylon (elasticity, durability, ability to be dyed) and kept clothes prices low and affordable.<ref name="Krier" />{{rp|2}} As of 1950, the New York Quartermaster Procurement Agency (NYQMPA), which developed and tested textiles for the [[United States Army|Army]] and [[United States Navy|Navy]], had committed to developing a wool-nylon blend. They were not the only ones to introduce blends of both natural and synthetic fibres. ''America's Textile Reporter'' referred to 1951 as the "Year of the blending of the fibres".<ref name="Haggard">{{cite journal|last1=Haggard|first1=John V.|title=Chapter III: Collaborative Procurement of Textiles|journal=Procurement of Clothing and Textiles, 1945-53|date=16 May 1957|volume=2|issue=3|pages=79–84|url=https://books.google.com/books?id=9Pw6alchdDkC&pg=PA79}}</ref> Fabric blends included mixes like "Bunara" (wool-rabbit-nylon) and "Casmet" (wool-nylon-fur).<ref name="Handley"/> In Britain, in November 1951, the inaugural address of the 198th session of the Royal Society for the Encouragement of Arts, Manufactures and Commerce focused on the blending of textiles.<ref name="GOODALE">{{cite journal|last1=Goodale|first1=Ernest W.|title=The Blending & Mixture of Textile Fibres & Yarns|journal=Journal of the Royal Society of Arts|date=16 November 1951|volume=100|issue=4860|pages=4–15|jstor=41368063}}</ref>

DuPont's Fabric Development Department cleverly targeted French fashion designers, supplying them with fabric samples. In 1955, designers such as [[Coco Chanel]], [[Jean Patou]], and [[Christian Dior]] showed gowns created with DuPont fibres, and fashion photographer [[Horst P. Horst]] was hired to document their use of DuPont fabrics.<ref name="Wolfe2008"/> ''American Fabrics'' credited blends with providing "creative possibilities and new ideas for fashions which had been hitherto undreamed of."<ref name="Handley">{{cite book|last1=Handley|first1=Susannah|title=Nylon: The Story of a Fashion Revolution|date=1999|publisher=Johns Hopkins University Press|location=Baltimore, MD|isbn=978-0756771720|page=68|url=https://books.google.com/books?id=2YAYdk30VyIC&pg=PA68|access-date=26 June 2017}}</ref>

=== Etymology ===

DuPont went through an extensive process to generate names for its new product.<ref name="Meikle" />{{rp|138–139}} In 1940, John W. Eckelberry of DuPont stated that the letters "nyl" were arbitrary, and the "on" was copied from the suffixes of other fibres such as [[cotton]] and [[rayon]]. A later publication by DuPont (''Context'', vol.&nbsp;7, no.&nbsp;2, 1978) explained that the name was originally intended to be "No-Run" ("run" meaning "unravel") but was modified to avoid making such an unjustified claim. Since the products were not really run-proof, the vowels were swapped to produce "nuron", which was changed to "nilon" "to make it sound less like a nerve tonic". For clarity in pronunciation, the "i" was changed to "y".<ref name="Wolfe2008" /><ref>{{cite book |url=https://books.google.com/books?id=znFmBZ2D8rEC&pg=PA224 |title=The Origins and Development of the English Language |last=Algeo |first=John |publisher=Cengage |year=2009 |isbn=9781428231450 |volume=6 |page=224 |author-link=John Algeo}}</ref>

A persistent [[urban legend]] exists that the name is derived from "New York" and "London"; however, no organisation in London was ever involved in the research and production of nylon.<ref>{{cite book |title=Word Myths: Debunking Linguistic Urban Legends |first=David |last=Wilton |page=88 |publisher=Oxford University Press |year=2008 |isbn=978-0-199-74083-3}}</ref>

=== Longer-term popularity ===
Nylon’s popularity soared in the 1940s and 1950s due to its durability and sheerness. In the 1970s, it became more popular due to its flexibility and price.

In spite of oil shortages in the 1970s, consumption of nylon textiles continued to grow by 7.5% per year between the 1960s and 1980s.<ref name="Wilson">{{cite book |url=https://books.google.com/books?id=Qc8mDwAAQBAJ&pg=PA246 |title=Petrocultures: Oil, Politics, Culture |last1=Wilson |first1=Sheena |last2=Carlson |first2=Adam |last3=Szeman |first3=Imre |date=2017 |publisher=McGill-Queen's University Press |location=Montreal, Quebec |pages=246 |isbn=9780773550391 |author-link3=Imre Szeman |access-date=26 June 2017}}</ref> Overall production of synthetic fibres, however, dropped from 63% of the worlds textile production in 1965, to 45% of the world's textile production in early 1970s.<ref name="Wilson" /> The appeal of "new" technologies wore off, and nylon fabric "was going out of style in the 1970s".<ref name="Ndiaye" /> Also, consumers became concerned about environmental costs throughout the production cycle: obtaining the raw materials (oil), energy use during production, waste produced during creation of the fibre, and eventual waste disposal of materials that were not biodegradable.<ref name="Wilson" /> 
Synthetic fibres have not dominated the market since the 1950s and 1960s. {{As of|2020}}, the worldwide production of nylon is estimated at 8.9 million tons.<ref name="Businesswire">{{cite news |url=https://www.businesswire.com/news/home/20200730005398/en/Global-Nylon-Market-Analysis-and-Outlook-2020-2027---Nylon-6-Volumes-Will-Reach-5.3-Million-Tons-by-2027-Despite-COVID-19---ResearchAndMarkets.com |title=Global Nylon Market Analysis and Outlook 2020-2027 - Nylon 6}}</ref>

Although pure nylon has many flaws and is now rarely used, its derivatives have greatly influenced and contributed to society. From scientific discoveries relating to the production of plastics and polymerisation, to economic impact during the depression and the changing of women's fashion, nylon was a revolutionary product.<ref name="Wolfe2008" /> The [[Lunar Flag Assembly]], the first flag planted on the moon in a symbolic gesture of celebration, was made of nylon. The flag itself cost $5.50 but had to have a specially designed flagpole with a horizontal bar so that it would appear to "fly".<ref name="Welsh">{{Cite news |url=https://www.businessinsider.com/apollo-flags-moon-faded-white-2016-5?r=US&IR=T |title=The American Flags on the Moon Have All Turned White |last=Welsh |first=Jennifer |date=21 May 2016 |work=Business Insider |access-date=14 April 2017}}</ref><ref name="Platoff">{{cite web |url=https://www.jsc.nasa.gov/history/flag/flag.htm |title=NASA Contractor Report 188251 Where No Flag Has Gone Before: Political and Technical Aspects of Placing a Flag on the Moon |last1=Platoff |first1=Anne M. |date=1993 |website=NASA |access-date=26 June 2017}}</ref> One historian describes nylon as "an object of desire", comparing the invention to Coca-Cola in the eyes of 20th century consumers.<ref name="Ndiaye" />

== Chemistry ==
{{external media | width = 210px | float = right | headerimage= | video1 = [https://www.youtube.com/watch?v=y479OXBzCBQ "Making Nylon"], Bob Burk, CHEM 1000, Carleton University, Ottawa, Canada | video2 = [https://www.youtube.com/watch?v=HTh_5CWMSoQ "Making Nylon 6,6"] | video3= [https://www.youtube.com/watch?v=4GxeSO7DyaE "Nylon production"], [[Royal Society of Chemistry]] |video4= [https://www.youtube.com/watch?v=Qos7E7dDMyo "Nylon and Rayon Manufacture 1949"], Encyclopedia Britannica Films }}

In common usage, the prefix "PA" ([[polyamide]]) or the name "Nylon" are used interchangeably and are equivalent in meaning.

The nomenclature used for nylon polymers was devised during the synthesis of the first simple aliphatic nylons and uses numbers to describe the number of carbons in each monomer unit, including the carbon(s) of the carboxylic acid(s).<ref>{{cite book |last=Cowie |first=J. M. G. |title=Polymers: Chemistry and Physics of Modern Materials |edition=2nd |publisher=Blackie |date=1991 |pages=[https://archive.org/details/polymerschemistr0000cowi/page/16 16–17] |isbn=0-216-92980-6 |url=https://archive.org/details/polymerschemistr0000cowi/page/16 }}</ref><ref>{{cite book |last=Rudin |first=Alfred |title=Elements of Polymer Science and Engineering |publisher=Academic Press |date=1982 |pages=[https://archive.org/details/elementsofpolyme0000rudi/page/32 32–33] |isbn=0-12-601680-1 |url=https://archive.org/details/elementsofpolyme0000rudi/page/32 }}</ref> Subsequent use of cyclic and aromatic monomers required the use of letters or sets of letters. One number after "PA" or "Nylon" indicates a [[homopolymer]] which is ''monadic'' or based on one amino acid (minus H<sub>2</sub>O) as monomer:
: PA 6 or Nylon 6: [NH−(CH<sub>2</sub>)<sub>5</sub>−CO]<sub>''n''</sub> made from ε-caprolactam.

Two numbers or sets of letters indicate a ''dyadic'' homopolymer formed from two monomers: one diamine and one dicarboxylic acid. The first number indicates the number of carbons in the diamine. The two numbers should be separated by a comma for clarity, but the comma is often omitted.
: PA or Nylon 6,10 (or 610): [NH−(CH<sub>2</sub>)<sub>6</sub>−NH−CO−(CH<sub>2</sub>)<sub>8</sub>−CO]<sub>''n''</sub> made from [[hexamethylenediamine]] and [[sebacic acid]];

For copolymers the comonomers or pairs of comonomers are separated by slashes:
: PA 6/66: [NH−(CH<sub>2</sub>)<sub>6</sub>−NH−CO−(CH<sub>2</sub>)<sub>4</sub>−CO]<sub>''n''</sub>−[NH−(CH<sub>2</sub>)<sub>5</sub>−CO]<sub>''m''</sub> made from caprolactam, hexamethylenediamine and adipic acid;
: PA 66/610: [NH−(CH<sub>2</sub>)<sub>6</sub>−NH−CO−(CH<sub>2</sub>)<sub>4</sub>−CO]<sub>''n''</sub>−[NH−(CH<sub>2</sub>)<sub>6</sub>−NH−CO−(CH<sub>2</sub>)<sub>8</sub>−CO]<sub>''m''</sub> made from hexamethylenediamine, adipic acid and sebacic acid.

The term [[polyphthalamide]] (abbreviated to PPA) is used when 60% or more moles of the carboxylic acid portion of the repeating unit in the polymer chain is composed of a combination of [[terephthalic acid]] (TPA) and [[isophthalic acid]] (IPA).

== Types ==

=== Nylon 66 and related heteropolymers ===
{{Main|Nylon 66}}

Nylon 66 and related polyamides are [[condensation polymer]]s forms from equal parts of [[diamine]] and [[dicarboxylic acid]]s.<ref name="Ratner">{{cite book|last1=Ratner|first1=Buddy D.|title=Biomaterials science : an introduction to materials in medicine|date=2013|publisher=Elsevier|location=Amsterdam|isbn=9780080877808|pages=74–77|edition=3rd|url=https://books.google.com/books?id=8hBq-dLLaxwC&pg=PA75|access-date=5 July 2017}}</ref> In the first case, the "repeating unit" has the ABAB structure, as also seen in many [[polyester]]s and [[polyurethane]]s. Since each monomer in this copolymer has the same [[functional group|reactive group]] on both ends, the direction of the [[peptide bond|amide bond]] reverses between each monomer, unlike natural [[polyamide]] [[protein]]s, which have overall directionality: [[carboxyl|C&nbsp;terminal]]&nbsp;→ [[amino|N&nbsp;terminal]]. In the second case (so called AA), the repeating unit corresponds to the single monomer.<ref name="McIntyre"/>{{rp|45–50}}<ref name="Denby">{{cite book|last1=Denby|first1=Derek|last2=Otter|first2=Chris|last3=Stephenson|first3=Kay|title=Chemical storylines.|date=2008|publisher=Heinemann|location=Oxford|isbn=9780435631475|page=96|edition=3rd|url=https://books.google.com/books?id=Qj8qryYjlX0C&pg=RA1-PT68|access-date=5 July 2017}}</ref>

Wallace Carothers at DuPont patented [[nylon 66|nylon&nbsp;66]].<ref name="US 2130523">{{cite patent |country=US |number=2130523 |status=patent |gdate=1938-09-20 |fdate=1935-01-02 |pridate=1935-01-02 |invent1 =Carothers W.H. |title=Linear polyamides and their production |assign1=EI Du Pont de Nemours and Co.}}</ref><ref>{{cite web|title=Diamine-dicarboxylic acid salts and process of preparing same US 2130947 A|url=https://patents.google.com/patent/US2130947|website=Patents|access-date=19 June 2017}}</ref><ref>{{cite web|title=Synthetic fiber US 2130948 A|url=https://patents.google.com/patent/US2130948|website=Patents|access-date=19 June 2017}}</ref> 
In the case of nylons that involve reaction of a diamine and a dicarboxylic acid, it is difficult to get the proportions exactly correct, and deviations can lead to chain termination at molecular weights less than a desirable 10,000 [[Dalton (unit)|dalton]]s. To overcome this problem, a [[crystal]]line, solid "nylon [[Salt (chemistry)|salt]]" can be formed at [[room temperature]], using an exact 1:1 [[ratio]] of the [[acid]] and the [[Base (chemistry)|base]] to neutralise each other. The salt is crystallised to purify it and obtain the desired precise stoichiometry. Heated to {{cvt|285|C}}, the salt reacts to form nylon polymer with the production of water.

Nylon&nbsp;510, made from [[pentamethylene diamine]] and sebacic acid, was included in the Carothers patent to nylon&nbsp;66<ref name="US 2130523" /> Nylon 610 is produced similarly using hexamethylene diamine. These materials are more expensive because of the relatively high cost of sebacic acid. Owing to the high [[hydrocarbon]] content, nylon 610 is more hydrophobic and finds applications suited for this property, such as bristles.<ref>{{cite book |doi=10.1002/14356007.a10_567.pub2|chapter=Fibers, 4. Polyamide Fibers |title=Ullmann's Encyclopedia of Industrial Chemistry |year=2011 |last1=Estes |first1=Leland L. |last2=Schweizer |first2=Michael |isbn=978-3527306732 }}</ref>
<!--In keeping with this naming convention, "nylon&nbsp;6,12" or "PA 612" is a copolymer of a 6C diamine and a 12C diacid. Similarly for PA 510 PA 611; PA 1012, etc. Other nylons include copolymerised dicarboxylic acid/diamine products that are ''not'' based upon the monomers listed above. For example, some fully [[aromatic]] nylons (known as "[[aramids]]") are polymerised with the addition of diacids like terephthalic acid (→ [[Kevlar]], [[Twaron]]) or isophthalic acid (→ [[Nomex]]), more commonly associated with polyesters. There are copolymers of PA 66/6; copolymers of PA 66/6/12; and others. In general linear polymers are the most useful, but it is possible to introduce branches in nylon by the condensation of dicarboxylic acids with [[polyamine]]s having three or more [[amino group]]s.

The general reaction is:
[[Image:Condensation polymerization diacid diamine.svg|centre|600px]]

Two molecules of [[water (molecule)|water]] are given off and the nylon is formed. Its properties are determined by the R and R' groups in the monomers. In nylon 6,6, R&nbsp;=&nbsp;4C and R'&nbsp;=&nbsp;6C [[alkane]]s, but one also has to include the two carboxyl [[carbon]]s in the diacid to get the number it donates to the chain. In Kevlar, both R and R' are [[benzene]] rings.

Industrial synthesis is usually done by heating the acids, amines or lactams to remove water, but in the laboratory, diacid chlorides can be reacted with diamines. For example, a popular demonstration of interfacial polymerisation (the "[[nylon rope trick]]") is the synthesis of nylon 66 from [[adipoyl chloride]] and hexamethylene diamine.
-->

{| class="wikitable"
|+Commercial heteropolymer polyamides
!  !! [[Putrescine|1,4-diamino&shy;butane]]  || [[Cadaverine|1,5-diamino&shy;pentane]] !! [[2-Methylpentamethylenediamine|MPMD]] !! [[Hexamethylenediamine|HMD]] !! [[m-Xylylenediamine|MXDA]] !! Nonane&shy;diamine !! Decane&shy;diamine !!Dodecane&shy;diamine !! [[4,4-Diaminodicyclohexylmethane|Bis&shy;(para-amino&shy;cyclohexyl)&shy;methane]] !![[trimethylhexamethylenediamine|Trimethyl&shy;hexamethylene&shy;diamine]]
|-
|[[Adipic acid]]              ||[[Nylon 46|46]]|| || D6|| [[nylon 6-6|66]] ||MXD6||       ||        ||       ||       ||
|-
|[[Sebacic acid]]            ||  410  ||   510  ||   ||  610   ||         ||  ||     1010   ||     ||        ||
|-
|[[Dodecanedioic acid]]||     ||    ||     ||612||  ||     ||       ||1212 ||[[Qiana|PACM12]]||
|-
|[[Terephthalic acid]]   || 4T||  ||  DT||6T ||      || 9T || 10T||12T ||       ||[[Trogamid|TMDT]]
|-
|[[Isophthalic acid]]    ||  ||     || DI ||6I ||   ||     ||         ||       ||       ||
|}

Examples of these polymers that are or were commercially available:
* PA46 DSM Stanyl<ref>{{cite web|title=Stanyl® Polyamide 46: Driving change in automotive|url=http://www.dsm.com/markets/automotive/en_US/products-brands/stanyl.html|website=DSM|access-date=19 June 2017}}</ref>
* PA410 DSM Ecopaxx<ref>{{cite web|title=EcoPaXX: The green performer|url=http://www.dsm.com/products/ecopaxx/en_US/home.html|website=DSM|access-date=19 June 2017}}</ref>
* PA4T DSM Four Tii<ref>{{cite web|title=ForTii® Pushing peak performance|url=http://www.dsm.com/products/stanylfortii/en_US/home.html|website=DSM|access-date=19 June 2017}}</ref>
* PA66 DuPont Zytel<ref>{{cite web|title=zytel - PA6, PA610, PA612, PA66 - dupont|url=http://www.materialdatacenter.com/ms/en/zytel/dupont/839|website=Material Data Center|access-date=19 June 2017}}</ref>

=== Nylon 6 and related homopolymers ===
{{Main|Nylon 6}}

These polymers are made from a lactam or amino acid. The synthetic route using lactams (cyclic amides) was developed by [[Paul Schlack]] at [[IG Farben]], leading to nylon&nbsp;6, or [[caprolactam|polycaprolactam]]—formed by a [[ring-opening polymerization|ring-opening polymerisation]]. The peptide bond within the caprolactam is broken with the exposed [[functional group|active groups]] on each side being incorporated into two new bonds as the monomer becomes part of the polymer backbone.

The {{cvt|220|C}} melting point of nylon 6 is lower than the {{cvt|265|C}} melting point of [[nylon 66]].<ref>{{cite web|title=Fiber-reinforced composite articles and methods of making them CA 2853925 A1|url=https://patents.google.com/patent/CA2853925A1|website=Patents|access-date=19 June 2017}}</ref> Homopolymer nylons are derived from one monomer.

{| class="wikitable"
|-
! Monomer !! Polymer
|-
| [[Caprolactam]] || [[Nylon 6|6]]
|-
| [[11-aminoundecanoic acid]] || [[Nylon 11|11]]
|-
| ω-aminolauric acid || [[Nylon 12|12]]
|}

Examples of these polymers that are or were commercially available:
* PA6 Lanxess Durethan B<ref>{{cite web|title=Durethan® is the trade name for our range of engineering thermoplastics based on polyamide 6 and polyamide 66.|url=https://techcenter.lanxess.com/scp/americas/en/products/description/47/index.jsp?pid=47|website=LANXESS Energizing Chemistry|access-date=19 June 2017}}</ref>
* PA11 Arkema Rilsan<ref name="Arkema">{{cite web|title=Polyamide Resins for an Extreme World Flagship Rilsan® PA11 and Complementary Resins & Alloys|url=http://www.rilsan.com/en/rilsan-pa11/pa11-product-information/index.html|website=Arkema|access-date=19 June 2017}}</ref>
* PA12 Evonik Vestamid L<ref>{{cite web|title=VESTAMID® L—polyamide 12|url=http://www.vestamid.com/product/vestamid/en/products-services/vestamid-l/pages/default.aspx|website=EVONIK|access-date=19 June 2017}}</ref>

=== Nylon 1,6 ===
{{Main|Nylon 1,6}}

Nylons can also be synthesised from dinitriles using acid catalysis. For example, this method is applicable for preparation of [[nylon 1,6]] from [[adiponitrile]], [[formaldehyde]] and water.<ref>{{Cite journal|last1=Magat|first1=Eugene E.|last2=Faris|first2=Burt F.|last3=Reith|first3=John E.|last4=Salisbury|first4=L. Frank|date=1951-03-01|title=Acid-catalyzed Reactions of Nitriles. I. The Reaction of Nitriles with Formaldehyde1|journal=Journal of the American Chemical Society|volume=73|issue=3|pages=1028–1031|doi=10.1021/ja01147a042|bibcode=1951JAChS..73.1028M |issn=0002-7863}}</ref> Additionally, nylons can be synthesised from [[diol]]s and dinitriles using this method as well.<ref>{{Cite journal|last1=Lakouraj|first1=Moslem Mansour|last2=Mokhtary|first2=Masoud|date=2009-02-20|title=Synthesis of polyamides from p-Xylylene glycol and dinitriles|journal=Journal of Polymer Research|language=en|volume=16|issue=6|pages=681|doi=10.1007/s10965-009-9273-z|s2cid=98232570|issn=1022-9760}}</ref>

=== Copolymers ===

It is easy to make mixtures of the monomers or sets of monomers used to make nylons to obtain copolymers. This lowers [[crystallinity]] and can therefore lower the melting point.

Some copolymers that have been or are commercially available are listed below: 
* PA6/66 DuPont Zytel<ref>{{cite web|title=Zytel® 74G33EHSL NC010|url=http://catalog.ides.com/Datasheet.aspx?I=9837&U=0&E=92285|website=DISTRUPOL|access-date=19 June 2017}}</ref>
* PA6/6T BASF Ultramid T (6/6T copolymer)<ref name="Kutz"/>
* PA6I/6T DuPont Selar PA<ref>{{cite web|title=DuPont TM Selar® PA 2072|url=http://www.dupont.ca/content/dam/dupont/products-and-services/packaging-materials-and-solutions/packaging-materials-and-solutions-landing/documents/selar_pa_2072.pdf|website=DuPont|archive-url=https://web.archive.org/web/20150419021438/http://www.dupont.ca/content/dam/dupont/products-and-services/packaging-materials-and-solutions/packaging-materials-and-solutions-landing/documents/selar_pa_2072.pdf|access-date=19 June 2017|archive-date=2015-04-19}}</ref>
* PA66/6T DuPont Zytel HTN<ref name="Kutz">{{cite book|last1=Kutz|first1=Myer|title=Applied plastics engineering handbook processing and materials|date=2011|publisher=William Andrew|location=Amsterdam|isbn=9781437735154|page=5|edition=1st|url=https://books.google.com/books?id=1I3_CgAAQBAJ&pg=PA5|access-date=19 June 2017}}</ref>
* PA12/MACMI EMS Grilamid TR<ref>{{cite web|title=Grilamid L PA12|url=http://www.emsgrivory.com/en/products-markets/products/grilamid/grilamid-l-pa12/|website=EMS|access-date=19 June 2017}}</ref>

=== Blends ===

Most nylon polymers are miscible with each other allowing a range of blends to be made. The two polymers can react with one another by transamidation to form random copolymers.<ref>{{cite journal| last1=Samperi| first1=Filippo| last2=Montaudo| first2=Maurizio S.| last3=Puglisi| first3=Concetto| last4=Di Giorgi|first4=Sabrina|last5=Montaudo|first5=Giorgio|title=Structural Characterization of Copolyamides Synthesized via the Facile Blending of Polyamides| journal=Macromolecules| date=August 2004| volume=37| issue=17| pages=6449–6459| doi=10.1021/ma049575x| bibcode=2004MaMol..37.6449S}}</ref>

=== Crystallinity===
According to their crystallinity, polyamides can be:
* semi-[[crystal]]line: 
** high crystallinity: PA46 and PA66;
** low crystallinity: PAMXD6 made from m-xylylenediamine and adipic acid;
* [[Amorphous solid|amorphous]]: PA6I made from hexamethylenediamine and isophthalic acid.

According to this classification, PA66, for example, is an aliphatic semi-crystalline homopolyamide.

== Environmental impact ==
[[file:amide hydrolysis.svg|thumb|The general chemical reaction involving hydrolysis of an amide to form a carboxylic acid and an amine]]

All nylons are susceptible to [[hydrolysis]], especially by [[strong acid]]s, a reaction essentially the reverse of their synthesis. The [[molecular weight]] of nylon products so attacked drops, and cracks form quickly at the affected zones. Lower members of the nylons (such as nylon 6) are affected more than higher members such as nylon 12. This means that nylon parts cannot be used in contact with [[sulfuric acid]] for example, such as the electrolyte used in [[Lead–acid battery|lead–acid batteries]].

When being molded, nylon must be dried to prevent hydrolysis in the molding machine barrel since water at high temperatures can also degrade the polymer.<ref name="Reltek">{{cite web|url=http://reltekllc.com/adhesivesfornylon.aspx|title=Adhesive for nylon & kevlar|website=Reltek|access-date=27 January 2015}}</ref> The reaction is shown above.

The average [[GHG footprint|greenhouse gas footprint]] of nylon in manufacturing carpets is estimated at 5.43&nbsp;kg CO<sub>2</sub> equivalent per kg, when produced in Europe. This gives it almost the same [[carbon footprint]] as [[wool]], but with greater durability and therefore a lower overall carbon footprint.<ref name="Berners-Lee">{{cite book|title=How bad are bananas? : the carbon footprint of everything|last1=Berners-Lee|first1=Mike|date=2010|publisher=Profile Books|location=London|page=112, table 6.1}}</ref>

Data published by PlasticsEurope indicates for nylon 66 a [[GHG footprint|greenhouse gas footprint]] of 6.4&nbsp;kg CO<sub>2</sub> equivalent per kg, and an energy consumption of 138 kJ/kg.<ref>{{cite book|url=http://www.plasticseurope.org/plasticssustainability/eco-profiles/browse-by-flowchart.aspx?LCAID=r307|title=Eco-profiles and Environmental Product Declarations of the European Plastics Manufacturers: Polyamide 6.6|date=2014|publisher=PlasticsEurope AISBL|location=Brussels|access-date=2015-04-19|archive-url=https://web.archive.org/web/20150427111338/http://www.plasticseurope.org/plasticssustainability/eco-profiles/browse-by-flowchart.aspx?LCAID=r307|archive-date=2015-04-27|url-status=dead}}</ref> When considering the environmental impact of nylon, it is important to consider the use phase.

Various nylons break down in fire and form hazardous smoke, and toxic fumes or ash, typically containing [[hydrogen cyanide]]. [[Incineration|Incinerating]] nylons to recover the high energy used to create them is usually expensive, so most nylons reach the garbage dumps, decaying slowly.{{efn|Typically 80 to 100% is sent to landfill or garbage dumps, while less than 18% are incinerated while recovering the energy. See {{cite book|url=https://books.google.com/books?id=TBrOGJqvgcMC&pg=PA19|title=Handbook of plastics recycling|author=Francesco La Mantia|date=August 2002|publisher=iSmithers Rapra Publishing|isbn=978-1-85957-325-9|pages=19–}}}} Discarded nylon fabric takes 30–40 years to decompose.<ref>{{cite web|url=https://www.des.nh.gov/organization/divisions/water/wmb/coastal/trash/documents/marine_debris.pdf|title=Approximate Time it Takes for Garbage to Decompose in the Environment|publisher=NH Department of Environmental Services|archive-url=https://web.archive.org/web/20090413220235/https://www.des.nh.gov/organization/divisions/water/wmb/coastal/trash/documents/marine_debris.pdf|access-date=31 March 2018|archive-date=2009-04-13}}</ref> Nylon used in discarded fishing gear such as fishing nets is a contributor to debris in the ocean.<ref name="chhabra">{{cite web |last1=Chhabra |first1=Esha |title=Recycling nylon is good for the planet – so why don't more companies do it? |url=https://www.theguardian.com/sustainable-business/2016/may/18/recycling-nylon-bureo-patagonia-sustainable-clothing |website=The Guardian |access-date=21 April 2021 |date=18 May 2016}}</ref> Nylon is a robust polymer and lends itself well to recycling. Much nylon resin is recycled directly in a closed loop at the injection molding machine, by grinding [[Sprue (manufacturing)|sprues]] and runners and mixing them with the virgin granules being consumed by the molding machine.<ref name="Boydell">{{cite journal|last1=Boydell|first1=P|last2=Bradfield|first2=C|last3=von Falkenhausen|first3=V|last4=Prautzsch|first4=G|date=1995|title=Recycling of Waste from Glass-reinforced nylon resins|journal=Engineering Design|volume=2|pages=8–10}}</ref>

Because of the expense and difficulties of the nylon recycling process, few companies utilise it while most favor using cheaper, newly made plastics for their products instead.<ref name="chhabra"/> US clothing company [[Patagonia, Inc.|Patagonia]] has products containing recycled nylon and in the mid-2010s invested in Bureo, a company that recycles nylon from used fishing nets to use in sunglasses and skateboards.<ref name="chhabra"/> The Italian company Aquafil also has demonstrated recycling fishing nets lost in the ocean into apparel.<ref>{{cite journal |last1=Maile |first1=Kelly |title=How abandoned fishing nets are recycled into nylon |journal=Recycling Today |date=January 18, 2019 |url=https://www.recyclingtoday.com/article/abandoned-fishing-nets-recycled-into-nylon/ |access-date=15 March 2019}}</ref> Vanden Recycling recycles nylon and other polyamides (PA) and has operations in the UK, Australia, Hong Kong, the UAE, Turkey and Finland.<ref>{{cite web |publisher=Vanden Recycling |title=PA / Nylon fibres are used in textiles, fishing line and carpets. |url=https://www.vandenrecycling.com/en/products/pa/ |access-date=7 Feb 2020}}</ref>

Nylon is the most popular fibre type in the residential carpet industry today.<ref>{{cite web |author=EPA |title= Nylon Carpet: Pros and Cons |date= 19 October 2018 |url=https://www.avalonflooring.com/ideas/blog/nylon-carpet-pros-cons |access-date=27 May 2021}}</ref> The US [[EPA]] estimates that 9.2% of carpet fibre, backing and padding was recycled in 2018, 17.8% was incinerated in [[waste-to-energy]] facilities, and 73% was discarded in [[landfill]]s.<ref>{{cite web |author=EPA |title= Durable Goods: Product-Specific Data (Carpets and Rugs)|date= 7 September 2017|url= https://www.epa.gov/facts-and-figures-about-materials-waste-and-recycling/durable-goods-product-specific-data#CarpetsandRugs |access-date=27 May 2021}}</ref> Some of the world's largest carpet and rug companies are promoting "cradle to cradle"—the re-use of non-virgin materials including ones not historically recycled—as the industry's pathway forward.<ref>{{cite web |author=Floor covering weekly |title=Shaw recognized for Cradle to Cradle commitment. |url=https://www.floorcoveringweekly.com/main/topnews/shaw-recognized-for-cradle-to-cradle-commitment-33204 |access-date=27 May 2021}}</ref><ref>{{cite web |publisher=Shaw Industries |title= Cradle To Cradle® |url=https://shawinc.com/cradletocradle |access-date=27 May 2021}}</ref>

== Properties ==

Above their [[glass transition temperature|melting temperatures]], ''T''<sub>m</sub>, [[thermoplastic]]s like nylon are [[amorphous solid]]s or viscous [[fluid]]s in which the chains approximate [[random coil]]s. Below ''T''<sub>m</sub>, amorphous regions alternate with regions which are [[lamellae (materials)|lamellar]] [[crystal]]s.<ref>[https://web.archive.org/web/20041230231859/http://www.aml.arizona.edu/classes/mse222/1998/nylon66/mse222.htm Valerie Menzer's Nylon 66 Webpage]. Arizona University</ref> The amorphous regions contribute elasticity, and the crystalline regions contribute strength and rigidity. The [[Plane (geometry)|planar]] amide (-CO-NH-) groups are very [[chemical polarity|polar]], so nylon forms multiple [[hydrogen bond]]s among adjacent strands. Because the nylon backbone is so regular and symmetrical, especially if all the amide bonds are in the [[geometric isomerism|''trans'' configuration]], nylons often have high crystallinity and make excellent fibres. The amount of crystallinity depends on the details of formation, as well as on the kind of nylon.

[[File:Nylon-3D-h bond.png|thumb|upright=1.2|Hydrogen bonding in Nylon&nbsp;66 (in mauve)]]

Nylon&nbsp;66 can have multiple parallel strands aligned with their neighboring peptide bonds at coordinated separations of exactly six and four carbons for considerable lengths, so the [[carbonyl]] [[oxygen]]s and amide [[hydrogen]]s can line up to form interchain hydrogen bonds repeatedly, without interruption (see the figure opposite). Nylon&nbsp;510 can have coordinated runs of five and eight carbons. Thus parallel (but not antiparallel) strands can participate in extended, unbroken, multi-chain [[beta sheet|β-pleated sheets]], a strong and tough supermolecular structure similar to that found in natural [[keratin#Molecular biology and biochemistry|silk fibroin]] and the [[keratin|β-keratins]] in [[feather]]s. (Proteins have only an amino acid α-carbon separating sequential -CO-NH- groups.) Nylon&nbsp;6 will form uninterrupted [[hydrogen bond|H-bonded]] sheets with mixed directionalities, but the β-sheet wrinkling is somewhat different. The three-dimensional disposition of each [[alkane]] [[hydrocarbon chain]] depends on [[rotation]]s about the 109.47° [[alkane#Molecular geometry|tetrahedral]] bonds of singly bonded carbon atoms.

When [[extrusion|extruded]] into fibres through pores in an industry [[Spinneret (polymers)|spinneret]], the individual polymer chains tend to align because of [[viscosity|viscous]] [[rheology|flow]]. If subjected to [[cold drawing]] afterwards, the fibres align further, increasing their crystallinity, and the material acquires additional [[tensile strength]]. In practice, nylon fibres are most often drawn using heated rolls at high speeds.<ref name=Campbell>{{cite book|last1=Campbell|first1=Ian M.|title=Introduction to synthetic polymers|date=2000|publisher=Oxford Univ. Press|location=Oxford|isbn=978-0198564706}}</ref>

Block nylon tends to be less crystalline, except near the surfaces due to [[Shear (fluid)|shearing]] [[stress (physics)|stresses]] during formation. Nylon is clear and [[color|colourless]], or milky, but is easily [[dye]]d. Multistranded nylon cord and rope is slippery and tends to unravel. The ends can be [[melting|melted]] and fused with a heat source such as a [[flame]] or [[electrode]] to prevent this.

Nylons are hygroscopic and will absorb or desorb moisture as a function of the ambient humidity. Variations in moisture content have several effects on the polymer. Firstly, the dimensions will change, but more importantly moisture acts as a plasticiser, lowering the [[glass transition temperature]] (''T''<sub>g</sub>), and consequently the elastic modulus at temperatures below the ''T''<sub>g</sub><ref>{{cite web|title=Measurement of Moisture Effects on the Mechanical Properties of 66 Nylon - TA Instruments Thermal Analysis Application Brief TA-133|url=http://www.tainstruments.com/pdf/literature/TA133.pdf|website=TA Instruments|access-date=19 June 2017}}</ref>

When dry, polyamide is a good electrical insulator. However, polyamide is [[hygroscopic]]. The absorption of water will change some of the material's properties such as its [[electrical resistance]]. Nylon is less absorbent than wool or cotton.

The characteristic features of nylon 66 include:
* Pleats and creases can be heat-set at higher temperatures
* More compact molecular structure
* Better weathering properties; better sunlight resistance
* Softer "Hand"
* High melting point ({{cvt|256|C}})
* Superior colourfastness
* Excellent abrasion resistance

On the other hand, nylon 6 is easy to dye, more readily fades; it has a higher impact resistance, a more rapid moisture absorption, greater elasticity, and elastic recovery.
* Variation of luster: nylon has the ability to be very lustrous, semi-lustrous, or dull.
* Durability: its high tenacity fibres are used for seatbelts, tire cords, ballistic cloth, and other uses.
* High elongation
* Excellent abrasion resistance
* Highly resilient (nylon fabrics are heat-set)
* Paved the way for easy-care garments
* High resistance to insects, fungi, animals, as well as molds, mildew, rot, and many chemicals
* Used in carpets and nylon stockings
* Melts instead of burning
* Used in many military applications
* Good [[specific strength]]
* Transparent to infrared light (−12&nbsp;dB)<ref>{{cite journal|doi=10.1063/1.1771814|title=Millimeter-wave, terahertz, and mid-infrared transmission through common clothing|year=2004|last1=Bjarnason|first1=J. E.|last2=Chan|first2=T. L. J.|last3=Lee|first3=A. W. M.|last4=Celis|first4=M. A.|last5=Brown|first5=E. R.|journal=Applied Physics Letters|volume=85|issue=4|pages=519|bibcode=2004ApPhL..85..519B|doi-access=free}}</ref>{{clarify|reason=-12&nbsp;dB of which quantity?|date=August 2014}}

Nylon clothing tends to be less flammable than cotton and rayon, but nylon fibres may melt and stick to skin.<ref>{{cite web|url=https://kidshealth.schn.health.nsw.gov.au/flammable-clothing|title=Flammable clothing|website=The Children's Hospital at Westmead|date=24 February 2016 |access-date=5 July 2017}}</ref><ref name="Phillips">{{cite book|url=https://books.google.com/books?id=sDQrAAAAYAAJ&pg=PA30|title=Mass burns : proceeding of a workshop, 13-14 March 1968 / sponsored by the Committee on Fire Research, Division of Engineering, National Research Council and the Office of Civil Defense, Dept. of the Army|author=Workshop on Mass Burns (1968 : Washington, D.C.)|date=1969|publisher=National Academy of Sciences ; Springfield, Va. : reproduced by the Clearinghouse for Federal Scientific & Technical Information|editor-last1=Phillips|editor-first1=Anne W.|location=Washington, D.C.|page=30|access-date=5 July 2017|editor-last2=Walter|editor-first2=Carl W.}}</ref>

== Uses ==

Nylon was first used commercially in a nylon-[[bristle]]d [[toothbrush]] in 1938,<ref name="AOGHS"/><ref name="Nicholson"/> followed more famously in women's [[stocking]]s or "[[Fully fashioned stockings|nylons]]" which were shown at the [[1939 New York World's Fair]] and first sold commercially in 1940.<ref name="Wolfe2008"/> Its use increased dramatically during World War II, when the need for fabrics increased dramatically.

=== Fibres ===
[[File:The worn out nylon stockings in this barrel full of salvaged stockings will be reprocessed and made into parachutes... - NARA - 196427.jpg|thumb|upright=0.6|These worn out nylon stockings will be reprocessed and made into parachutes for army fliers {{circa|1942}}]]
[[File:Blue nylon ball gown 2007.154.jpg|thumb|upright=0.6|Blue nylon fabric ball gown by [[Emma Domb]], [[Science History Institute]] ]]

Bill Pittendreigh, [[DuPont]], and other individuals and corporations worked diligently during the first few months of World War II to find a way to replace Asian [[silk]] and [[hemp]] with nylon in parachutes. It was also used to make [[tire]]s, [[tent]]s, [[rope]]s, [[poncho]]s, and other [[armed forces|military]] supplies. It was even used in the production of a high-grade paper for U.S. [[currency]]. At the outset of the war, [[cotton]] accounted for more than 80% of all fibres used and manufactured, and [[wool]] fibres accounted for nearly all of the rest. By August 1945, manufactured fibres had taken a market share of 25%, at the expense of cotton. After the war, because of shortages of both silk and nylon, nylon parachute material was sometimes repurposed to make dresses.<ref>{{cite journal|last=Caruso|first=David|title=Saving the (Wedding) Day: Oral History Spotlight|journal=Transmutations|year=2009|volume=Fall|issue=5|pages=2|url=http://www.chemheritage.org/Downloads/Publications/Transmutations/05-Transmutations_Fall-2009.pdf|url-status=dead |archive-url=https://web.archive.org/web/20160509093859/http://www.chemheritage.org/Downloads/Publications/Transmutations/05-Transmutations_Fall-2009.pdf|archive-date=May 9, 2016}}</ref>

Nylon 6 and 66 fibres are used in [[Carpet#Nylon|carpet]] manufacture.

Nylon is one kind of fibre used in [[Tire#Materials|tire cord]]. [[Herman E. Schroeder]] pioneered application of nylon in tires.

=== Molds and resins ===

Nylon resins are widely used in the automobile industry especially in the engine compartment.<ref>{{cite web|title=Engine Oil Pan|url=http://www.materialdatacenter.com/mb/main/pdf/application/16449|website=www.materialdatacenter.com|access-date=19 June 2017}}</ref><ref name="Kohan"/>{{rp|514}}

Molded nylon is used in hair combs and [[machine|mechanical]] parts such as [[machine screw]]s, [[gear]]s, gaskets, and other low- to medium-stress components previously cast in metal.<ref>{{Cite web|url=https://www.espemfg.com/nylon-machining-fabrication.html|title=Nylon Machining & Fabrication {{!}} ESPE|website=www.espemfg.com|access-date=2018-08-28}}</ref><ref name=Youssef>{{cite book|last1=Youssef|first1=Helmi A.|last2=El-Hofy|first2=Hassan A.|last3=Ahmed|first3=Mahmoud H.|title=Manufacturing technology : materials, processes, and equipment|date=2011|publisher=Taylor & Francis/CRC Press|location=Boca Raton, FL|isbn=9781439810859|page=350|url=https://books.google.com/books?id=KGbNBQAAQBAJ&pg=PA350}}</ref> Engineering-grade nylon is processed by [[extrusion]], [[casting]], and [[injection molding]]. Type 6,6 Nylon 101 is the most common commercial grade of nylon, and Nylon 6 is the most common commercial grade of molded nylon.<ref>{{cite web|title=NYLON 6,6 (Nylon 6)|url=http://www.serrata.com.au/Instructions/1021048.pdf|website=Serrata|access-date=19 June 2017}}</ref><ref name="Difference">{{cite web|title=Nylon 6 vs. Nylon 66: What's the Difference?|url=http://www.polyone.com/idea/nylon-6-vs-nylon-66-whats-difference|website=PolyOne|access-date=5 July 2017}}</ref> For use in tools such as [[spudger]]s, nylon is available in [[glass-filled polymer|glass-filled variants]] which increase structural and impact strength and rigidity, and [[molybdenum disulfide]]-filled variants which increase [[lubricity]]. Nylon can be used as the matrix material in [[composite material]]s, with reinforcing fibres like glass or carbon fibre; such a composite has a higher [[density]] than pure nylon.<ref name=PerformanceComposites>{{cite web|title=Fiberglass and Composite Material Design Guide|url=http://www.performancecomposites.com/about-composites-technical-info/122-designing-with-fiberglass.html|website=Performance Composites Inc.|access-date=27 January 2015}}</ref> Such thermoplastic composites (25% to 30% glass fibre) are frequently used in car components next to the engine, such as intake manifolds, where the good heat resistance of such materials makes them feasible competitors to metals.<ref name=Page2000>{{cite book|last1=Page|first1=I. B.|title=Polyamides as engineering thermoplastic materials|date=2000|publisher=Rapra Technology Ltd.|location=Shawbury, Shrewsbury|isbn=9781859572207|page=115|url=https://books.google.com/books?id=Aj6dW2rRzqYC&pg=PA115}}</ref>

Nylon was used to make the stock of the [[Remington Nylon 66]] rifle.<ref name=Field1971>{{cite journal|title=How do you take care of a nylon 66 or 77? You don't|journal=Field & Stream|year=1971|volume=75|issue=9|url=https://books.google.com/books?id=GuHsz08Q32kC&pg=PA1}}</ref> The frame of the modern [[Glock]] pistol is made of a nylon composite.<ref name=Glock2013>{{cite book|last1=Sweeney|first1=Patrick|title=Glock deconstructed|date=2013|publisher=Krause|location=Iola, Wis.|isbn=978-1440232787|page=92|url=https://books.google.com/books?id=Zd0TiqiZgAUC&pg=PA92}}</ref>

=== Food packaging ===

Nylon resins are used as a component of food packaging films where an oxygen barrier is needed.<ref name="BPF"/> Some of the terpolymers based upon nylon are used every day in packaging. Nylon has been used for [[meat]] wrappings and [[sausage]] sheaths.<ref name=Colbert2013>{{cite book|last1=Colbert|first1=Judy|title=It happened in Delaware : remarkable events that shaped history|date=2013|publisher=Morris Book Publishing|isbn=978-0-7627-6968-1|edition=First|url=https://books.google.com/books?id=HJOEBAAAQBAJ&pg=PA62}}</ref> The high temperature resistance of nylon makes it useful for oven bags.<ref>{{cite web|title=Oven Bags|url=http://www.cooksinfo.com/oven-bags|website=Cooks Info|access-date=19 April 2015}}</ref>

=== Filaments ===

Nylon filaments are primarily used in brushes especially toothbrushes<ref name="AOGHS">{{cite news|title=Nylon, a Petroleum Polymer|url=http://aoghs.org/products/petroleum-product-nylon-fiber/|access-date=21 June 2017|work=American Oil and Gas Historical Society}}</ref> and [[string trimmer]]s. They are also used as monofilaments in [[Fishing line#Modern lines|fishing line]]. Nylon 610 and 612 are the most used polymers for filaments.

Its various properties also make it very useful as a material in [[additive manufacturing]]; specifically, as a filament in consumer and professional grade [[fused deposition modeling]] 3D printers.

=== Other forms ===

Nylon resins can be extruded into rods, tubes, and sheets.<ref name="Kohan"/>{{rp|209}}

Nylon powders are used to powder coat metals. [[Nylon 11]] and nylon 12 are the most widely used.<ref name="Kohan"/>{{rp|53}}

In the mid-1940s, classical guitarist [[Andrés Segovia]] mentioned the shortage of good guitar strings in the United States, particularly his favorite Pirastro [[catgut]] strings, to a number of foreign diplomats at a party, including General Lindeman of the British Embassy. A month later, the General presented Segovia with some nylon strings which he had obtained via some members of the DuPont family. Segovia found that although the strings produced a clear sound, they had a faint metallic [[timbre]] which he hoped could be eliminated.<ref name=Guitar>{{cite web|title=The History of Classical guitar strings|url=http://www.maestros-of-the-guitar.com/classicalguitarstrings.html|website=Maestros of the Guitar|access-date=27 January 2015}}</ref> Nylon strings were first tried on stage by Olga Coelho in New York in January 1944.<ref name="Bellow">{{cite book|last1=Bellow|first1=Alexander|title=The Illustrated History of the Guitar|date=1970|publisher=Franco Colombo|location=New York|page=193}}</ref> In 1946, Segovia and string maker [[Albert Augustine Ltd.|Albert Augustine]] were introduced by their mutual friend Vladimir Bobri, editor of Guitar Review. On the basis of Segovia's interest and Augustine's past experiments, they decided to pursue the development of nylon strings. DuPont, skeptical of the idea, agreed to supply the nylon if Augustine would endeavor to develop and produce the actual strings. After three years of development, Augustine demonstrated a nylon first string whose quality impressed guitarists, including Segovia, in addition to DuPont.<ref name=Guitar/> Wound strings, however, were more problematic. Eventually, however, after experimenting with various types of metal and smoothing and polishing techniques, Augustine was also able to produce high quality nylon wound strings.<ref name=Guitar/>

== See also ==

* {{annotated link|Ballistic nylon}}
* {{annotated link|Cordura}}
* {{annotated link|Forensic engineering}}
* {{annotated link|Nylon-eating bacteria}}
* {{annotated link|Polyamide}}
* {{annotated link|Ripstop nylon}}
* {{annotated link|Step-growth polymerization}}

== Notes ==
{{notelist}}

== References ==
{{reflist|30em}}

== Further reading ==
* {{cite book |title=Textiles |first=Sara J. |last=Kadolph |isbn=978-0-13-118769-6 |date=2007 |publisher=Pearson Prentice Hall |url-access=registration |url=https://archive.org/details/textiles0010kado }}
* {{cite book|last1=Kohan|first1=Melvin|title=Nylon Plastics Handbook|date=1995|publisher=Carl Hanser Verlag|location=Munich|isbn=1569901899}}
* {{cite magazine|title=How Nylon Yarn is Made |magazine=Popular Science |date=December 1946 |pages=132–3 |url=https://books.google.com/books?id=NSEDAAAAMBAJ&pg=PA132  |language=en}}

== External links ==
{{Commons}}
* {{YouTube|y479OXBzCBQ|Making Nylon, Bob Burk, CHEM 1000, Carleton University, Ottawa, Canada}}
* [https://www.ulprospector.com/plastics/en/generics/22 Polyamide Nylon Plastic]
* [https://digital.sciencehistory.org/collections/qf85nb39p Joseph X. Labovsky Collection of Nylon Photographs and Ephemera] [[Science History Institute]] Digital Collections. (High-resolution scans of nylon-related photographs and ephemera collected by Joseph X. Labovsky, a lab assistant to Wallace Carothers, during the early stages of nylon development and production at DuPont).

{{Plastics}}
{{Fibers}}
{{Fabric}}
{{Clothing materials and parts}}
{{DuPont}}
{{Authority control}}

[[Category:Products introduced in 1935]]
[[Category:American inventions]]
[[Category:Commodity chemicals]]
[[Category:Dielectrics]]
[[Category:DuPont products]]
[[Category:Plastics]]
[[Category:Polyamides]]
[[Category:Synthetic fibers]]

[[de:Polyamide#Nylon]]