<p><b style="font-size: 1rem;">Teflon:
the non-stick polymer: </b><span lang="" style="font-size: 1rem;">Teflon was discovered by
accident in<b> </b>1938 when Roy Plunkett,
a chemist<b> </b>working for the Du Pont
company on<b> </b>tetrafluoroethene gas,
could not get any<b>&nbsp;</b>of the gas from
one of the steel storage<b> </b>cylinders he
wanted to use. Instead of jumping to the conclusion that the gas must have
escaped, he weighed the cylinder and found that it weighed the same as if it
were full. He sawed it open and found a white powder, which turned out to be
poly(tetrafluoroethene) or PTFE - better known as <b>Teflon</b>. Ten years later it was in commercial production.</span></p><p style="text-align: center; "><img src="https://res.cloudinary.com/drrz8xekm/image/upload/v1560533063/wvmd4aouvioblgnsoja7.png" data-filename="wvmd4aouvioblgnsoja7" style="width: 527.5px;"><span lang="" style="font-size: 1rem;"><br></span></p><p class="MsoNormal" align="center" style="margin-bottom: 0.0001pt; line-height: normal; text-align: center;"><span style="font-size: 12pt; font-family: &quot;Times New Roman&quot;, serif;"><a href="https://pixabay.com/illustrations/egg-fried-sunny-eggs-side-pan-up-3249323/">Teflon makes this frying pan non-stick.<o:p></o:p></a></span></p><p class="MsoNormal" align="center" style="margin-bottom: 0.0001pt; line-height: normal; text-align: center;"><span class="MsoHyperlink"><span style="font-size: 12pt; font-family: &quot;Times New Roman&quot;, serif;"><a href="https://pixabay.com/illustrations/egg-fried-sunny-eggs-side-pan-up-3249323/">Pixabay</a></span></span></p><p class="MsoNormal"><span lang="">Teflon has a virtually friction-free surface,
is very resistant to heat and chemicals, and is an excellent electrical insulator.
Apart from its use as a coating on non-stick frying pans, Teflon is used to
coat bearings (even those that support loads as heavy as bridges) and in human
joint replacements, Unlike other polymers, its properties remain constant over
a wide temperature range (-70 to 350 °C).<o:p></o:p></span></p><h2><span lang="">DISSOLVING POLYMERS<o:p></o:p></span></h2><p class="MsoNormal"><span lang="">The addition polymers we have considered so
far do not dissolve in water, but if the groups along the polymer chain can
hydrogen-bond to water then the polymer may be soluble. Poly(ethenol) is one
such example. It is used to make dissolving laundry bags, particularly in
hospitals, where soiled laundry can go straight into the wash without having to
be handled. It is also used in liquid detergent capsules that can be put
directly into washing machines and dishwashers. Poly(ethanamide) can also
hydrogen-bond with water. One of the many uses of this polymer is in soft
contact lenses, where its ability to absorb water makes the lens soft.<o:p></o:p></span></p><h2><span lang="">CONDENSATION POLYMERISATION<o:p></o:p></span></h2><p class="MsoNormal"><span lang="">In 1928 a brilliant young American chemist,
Wallace Carothers, was invited to join the Du Pont company to head a team
researching into polymers. Here he made an immense contribution to our
understanding of polymer science, which was probably his most valuable work.
However, this is not what posterity remembers him for, because in 1935 he
produced the first nylon – a wholly synthetic fibre that mimics the protein,
silk, (which I will discuss on later).<o:p></o:p></span></p><p class="MsoNormal"><span lang="">Within three years of Carothers joining Du
Pont. His group produced the first commercial synthetic rubber. Neoprene (<i>neo</i> means new), an addition polymer. Then
they switched their attention to <b>condensation</b>
<b>polymerisation</b>. (When monomers form
condensation polymers, small molecules, such as water, are climinated.)
Carothers’ group investigated two different types of polymer: <b>polyesters</b> and <b>polyamides</b>. Their first success was the production of a polyester
fibre – the world’s first wholly synthetic fibre.</span></p><p class="MsoNormal"><span lang=""><br></span></p><p class="MsoNormal" style="text-align: center; "><img src="https://res.cloudinary.com/drrz8xekm/image/upload/v1560533206/ilfa9vxviezgzgj5isah.png" data-filename="ilfa9vxviezgzgj5isah" style="width: 527.5px;"><span lang=""><br></span></p><p class="MsoNormal"><span lang=""><o:p></o:p></span></p><p class="MsoNormal" align="center" style="margin-bottom: 0.0001pt; line-height: normal; text-align: center;"><span style="font-size: 12pt; font-family: &quot;Times New Roman&quot;, serif;"><a href="https://commons.m.wikimedia.org/wiki/File:PET_by_Polycondensation_V1.svg#mw-jump-to-license">PET by Polycondensation.<o:p></o:p></a><a name="_Hlt11428322"></a><a name="_Hlt11428321"></a></span></p><p><span lang=""></span></p><p class="MsoNormal" align="center" style="margin-bottom: 0.0001pt; line-height: normal; text-align: center;"><span class="MsoHyperlink"><span style="font-size: 12pt; font-family: &quot;Times New Roman&quot;, serif;"><a href="https://commons.m.wikimedia.org/wiki/File:PET_by_Polycondensation_V1.svg#mw-jump-to-license">[Jü • CC BY-SA 4.0]</a></span></span></p><h2><span lang="">POLYESTERS<o:p></o:p></span></h2><p class="MsoNormal"><span lang="">Carothers realised that for condensation
polymers to be formed, the monomers that make them up need two reactive ends.
So, taking for instance, monomer A could contain two COOH groups, while monomer
B could contain two OH groups, to give polyesters with monomer units joined by
ester functional groups.<o:p></o:p></span></p><p class="MsoNormal"><span lang="">The polyesters that the Du Pont team produced
were thought to be of theoretical interest, but of little practical use. The
water eliminated in the condensation reaction appeared to prevent the formation
of very long chains. This problem was solved by Carothers, who invented a
‘molecular still’ that evaporated the water molecules as they were produced.
This enabled very long polymer chains to be produced with M<sub>r</sub>, values
of about 10 000. However, the polyesters made of these were just sticky masses
when hot, and tough, opaque solids when cold. Then, in a happy accident, one of
the team, Julian Hill pulled a stirring rod out of a hot, sticky ball of
polyester. The result was a long, thin fibre of the polymer that, when it
cooled, could be stretched considerably and was very strong.<o:p></o:p></span></p><p class="MsoNormal"><span lang="">X-ray analysis revealed what had occurred.
Pulling the polymer into a long filament had aligned the polymer chains, which
increased the tensile strength of the material. The pulling process is known as
cold drawing.<o:p></o:p></span></p><p class="MsoNormal"><span lang="">The polyester fibres that the Du Pont group
led by Carothers produced were not destined for commercial success. Although the
fibres were strong and pliable, they melted at too low a temperature to be of
practical use in clothing, which would have to be ironed. They were also
slightly water soluble, another considerable disadvantage!<o:p></o:p></span></p><p class="MsoNormal"><span lang="">The polyester story now switches to the laboratories
of the Calico Printers Association in England, where in 1941 J Whinfield and J
Dickson invented Terylene, building on the foundations laid by Wallace Carothers.
This polyester is produced from benzene-1,4-dicarboxylic acid and the alcohol ethane-1,2-diol.
The systematic name for this polyester need not concern us. In industry, it is
usually referred to simply as polyester or PET.</span></p><p class="MsoNormal" style="text-align: center; "><img src="https://res.cloudinary.com/drrz8xekm/image/upload/v1560533268/c1biyeeqt2hwdvqrfem5.png" data-filename="c1biyeeqt2hwdvqrfem5" style="width: 476px;"><span lang=""><o:p><br></o:p></span></p><p class="MsoNormal" align="center" style="margin-bottom: 0.0001pt; line-height: normal; text-align: center;"><span style="font-size: 12pt; font-family: &quot;Times New Roman&quot;, serif;"><a href="https://commons.m.wikimedia.org/wiki/File:PET.svg#mw-jump-to-license">Polyethylene terephthalate.<o:p></o:p></a></span></p><p class="MsoNormal"><span lang=""><o:p></o:p></span></p><p class="MsoNormal" align="center" style="margin-bottom: 0.0001pt; line-height: normal; text-align: center;"><span class="MsoHyperlink"><span style="font-size: 12pt; font-family: &quot;Times New Roman&quot;, serif;"><a href="https://commons.m.wikimedia.org/wiki/File:PET.svg#mw-jump-to-license">[ljfa-ag Diskussion • Public domain]</a></span></span></p><p class="MsoNormal"><span lang="">The names Terylene and PET are derived from
the traditional names for the two monomers and the polymer, respectively. Benzene-1,4-dicarboxylic
acid is also called <b>tere</b>phthalic
acid and ethane 1,2-diol is also called ethy<b>lene</b> glycol – hence <b>Terylene</b>.
The traditional name for the polymer is <b>p</b>oly(<b>e</b>thylene <b>t</b>erephthalate), which gives the acronym <b>PET</b>.<o:p></o:p></span></p><p class="MsoNormal"><span lang="">Polyester is the leading synthetic fibre with
worldwide production of about 24 million tonnes. Its principal use is in
clothing, because it is crease-resistant. Often, it is mixed with other
synthetic or natural fibres. For example, a mixture of cotton and polyester is
very popular because the cotton absorbs moisture. Since polyester is a good
thermal insulator, duvets and anoraks are filled with its fibres. It is also
becoming the dominant material in packaging and is used in some carbonated
drinks bottles.</span></p><p class="MsoNormal" style="text-align: center; "><img src="https://res.cloudinary.com/drrz8xekm/image/upload/v1560533399/i5lrknmzqkkrvnq6ozen.jpg" data-filename="i5lrknmzqkkrvnq6ozen" style="width: 527.5px;"><span lang=""><o:p></o:p></span></p><p class="MsoNormal" style="text-align: center; "><span lang="">&nbsp;</span><a href="https://commons.m.wikimedia.org/wiki/File:Stretching_Polyester.JPG#mw-jump-to-license" style="font-family: &quot;Times New Roman&quot;, serif; font-size: 12pt; text-align: center; background-color: rgb(255, 255, 255);">Stretching polyester fabric.</a></p><p class="MsoNormal" align="center" style="margin-bottom: 0.0001pt; line-height: normal; text-align: center;"><span class="MsoHyperlink"><span style="font-size: 12pt; font-family: &quot;Times New Roman&quot;, serif;"><a href="https://commons.m.wikimedia.org/wiki/File:Stretching_Polyester.JPG#mw-jump-to-license">[Bearas • CC BY-SA 4.0]</a></span></span></p><h2><span lang="">NYLON: A POLYAMIDE<o:p></o:p></span></h2><p class="MsoNormal"><span lang="">After working on polyesters, Carothers and his
team focused their efforts on another type of polymer, in which the monomer
units are joined through secondary amide linkages, instead of ester linkages.
These secondary amide linkages are the same linkages as those found in proteins
such as silk.<o:p></o:p></span></p><p class="MsoNormal"><span lang="">In 1935, the team produced a polymer, now
called nylon 6,6, from a diamine and a dicarboxylic acid. Notice the similarity
of this condensation reaction to that which produces a polyester. Both use a dicarboxylic
acid monomer, but the alcohol groups at each end of the other monomer are
replaced with primary amine functional groups (NH<sub>2</sub>).<o:p></o:p></span></p><p class="MsoNormal"><span lang="">Nylon 6,6 is not the only polyamide that
Carothers’ team produced and so each is distinguished by a pair of numbers
unique to that nylon. The first number after the word nylon is the number of
carbon atoms in the diamine. The second number is the number of carbon atoms in
the dicarboxylic acid.<o:p></o:p></span></p><p class="MsoNormal"><span lang="">When nylon 6.6 is cold drawn, it is stretched
to four times its original length which gives the fibres so produced a high
tensile strength and elasticity. As a fibre is drawn, the polymer chains align
parallel to one another and the tensile strength comes from the hydrogen
bonding between the CO and NH groups of adjacent chains. The cold drawing also increases
the lustre (shininess) of nylon. In a commercial nylon plant, molten nylon is
forced through tiny holes to produce the fibres, which are then cold drawn.<o:p></o:p></span></p><p class="MsoNormal"><span lang="">Du Pont went from the laboratory preparation
of nylon 6,6 to its manufacture in the remarkably short time of less than five
years. By 1937 a pilot plant was operational, and by the end of 1939 a full
scale plant had been built and was in production – all this when the techniques
of large-scale condensation polymerisation were unknown and there were no bulk
supplies of either monomer. Add to this the different technologies required to
spin nylon fibres, and we have a remarkable achievement.<o:p></o:p></span></p><p class="MsoNormal"><span lang="">The first article to contain nylon was Dr
West’s Miracle Toothbrush, in which nylon bristles replaced animal bristles.
Meanwhile, Du Pont had test-marketed women’s nylon stockings and recognised
their enormous sales potential. Skirt lengths had become shorter and silk
stockings were highly fashionable, but were very expensive. When nylon
stockings became widely available in 1940, the commercial success of nylon was
assured. However, there was not enough production capacity to supply both the
consumer market and the United States war requirements, because nylon was in
great demand for ropes and, in particular, for parachutes, which had previously
been made from silk.</span></p><p class="MsoNormal" style="text-align: center; "><img src="https://res.cloudinary.com/drrz8xekm/image/upload/v1560533328/w9khemqzwqxqndfnwix1.png" data-filename="w9khemqzwqxqndfnwix1" style="width: 527.5px;"><span lang=""><o:p><br></o:p></span></p><p class="MsoNormal" align="center" style="margin-bottom: 0.0001pt; line-height: normal; text-align: center;"><span style="font-size: 12pt; font-family: &quot;Times New Roman&quot;, serif;"><a href="https://commons.m.wikimedia.org/wiki/File:Nylon6_and_Nylon_66.png#mw-jump-to-license">Nylon 6, 6.<o:p></o:p></a></span></p><p class="MsoNormal"><span lang=""><o:p></o:p></span></p><p class="MsoNormal" align="center" style="margin-bottom: 0.0001pt; line-height: normal; text-align: center;"><span class="MsoHyperlink"><span style="font-size: 12pt; font-family: &quot;Times New Roman&quot;, serif;"><a href="https://commons.m.wikimedia.org/wiki/File:Nylon6_and_Nylon_66.png#mw-jump-to-license" style="color: rgb(0, 133, 127); outline: 0px;">[Michael Ströck (mstroeck) at en.wikipedia • CC-BY-SA-3.0]</a></span></span></p><p class="MsoNormal"><span lang="">Nylon stockings were rationed in the US until
the end of the Second World War, and it took until the early 1950s before
production capacity in Western Europe matched the high demand for nylon
stockings and other nylon goods. Today, nylon goods account for 95 per cent of
the women’s hosiery market.<o:p></o:p></span></p><p class="MsoNormal"><span lang="">A variety of machine parts are now made from
nylon instead of metals. For these, its properties of toughness, strength and
abrasion resistance are much in demand, and specific properties are enhanced by
the use of <b>fillers</b> such as glass
fibre. Fillers are widely used to tailor the properties of polymers to specific
functions. Fillers are also added to provide bulk and make a cheaper product.</span></p><p class="MsoNormal" style="text-align: center; "><img src="https://res.cloudinary.com/drrz8xekm/image/upload/v1560533366/lshkeasoc6pwamlpppea.jpg" data-filename="lshkeasoc6pwamlpppea" style="width: 343px;"><span lang=""><o:p><br></o:p></span></p><p class="MsoNormal" align="center" style="margin-bottom: 0.0001pt; line-height: normal; text-align: center;"><span style="font-size: 12pt; font-family: &quot;Times New Roman&quot;, serif;"><a href="https://commons.m.wikimedia.org/wiki/File:Thistle_dinghy_with_skipper_Terry_Lettenmaier_sailing_downwind.jpg#mw-jump-to-license">Sailcloth is typically made from PET fibers also known as polyester<o:p></o:p></a></span></p><p class="MsoNormal"><span lang=""><o:p></o:p></span></p><p class="MsoNormal" align="center" style="margin-bottom: 0.0001pt; line-height: normal; text-align: center;"><span class="MsoHyperlink"><span style="font-size: 12pt; font-family: &quot;Times New Roman&quot;, serif;"><a href="https://commons.m.wikimedia.org/wiki/File:Thistle_dinghy_with_skipper_Terry_Lettenmaier_sailing_downwind.jpg#mw-jump-to-license">[Wikimedia, CC BY 2.5]</a></span></span></p><p class="MsoNormal"><span lang="">On a final note, here is a<b> brief history of Wallace Carothers</b>: Wallace Carothers was working
at the Du Pont company in Delaware. He led the research team that produced the
world’s first nylon. He was an internationally renowned expert on polymers, and
his theoretical ideas are the foundation of today’s polymer science. He was the
first industrial chemist to become a member of the prestigious National Academy
of Sciences in the USA.<o:p></o:p></span></p><p class="MsoNormal"><span lang="">However, his success masked the depression
that had plagued him since childhood and, in 1937, feeling that his life’s work
had been a failure, he committed suicide by drinking a solution of cyanide.
Yet, only three years later, nylon was proclaimed an outstanding commercial
success. <o:p></o:p></span></p><p class="MsoNormal"><span lang="">Oh! What a pity and such a sad ending.<o:p></o:p></span></p><p class="MsoNormal"><span lang="">Be on the look out for the other types of
polymers, examples, and their properties.<o:p></o:p></span></p><h2><span lang="">Thanks for reading.</span></h2><h2><span lang="">REFERENCES</span></h2><p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt;line-height:
normal"><span style="font-size:12.0pt;font-family:&quot;Times New Roman&quot;,&quot;serif&quot;;
mso-fareast-font-family:&quot;Times New Roman&quot;;mso-ansi-language:EN-US"><a href="file:///C:/Users/HP/Desktop/steemit%20pix/Why%20doesn't%20anything%20stick%20to%20Teflon?%20-%20Dec%2013,%202016%5d(https://www.google.com/url?sa=t&amp;source=web&amp;rct=j&amp;url=https://m.youtube.com/watch%3Fv%3DuXaP43Zbz7U&amp;ved=2ahUKEwjl3K7Lm-niAhWORhUIHd8jCAwQt9IBMBR6BAgLEBg&amp;usg=AOvVaw10oqCYBkGIPezjuuHVAO2_)">Why
doesn't anything stick to Teflon? - Dec 13, 2016</a></span></p><p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt;line-height:
normal"><span style="font-size:12.0pt;font-family:&quot;Times New Roman&quot;,&quot;serif&quot;;
mso-fareast-font-family:&quot;Times New Roman&quot;;mso-ansi-language:EN-US"><a href="file:///C:/Users/HP/Desktop/steemit%20pix/%5bThe%20Teflon%20Molecule%5d(https:/www.google.com/url?sa=t&amp;source=web&amp;rct=j&amp;url=https://www.worldofmolecules.com/materials/teflon.htm&amp;ved=2ahUKEwjl3K7Lm-niAhWORhUIHd8jCAwQFjAoegQIARAB&amp;usg=AOvVaw0R5-aiZZutKzGkTBDCi1kU)">The
Teflon Molecule</a></span></p><p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt;line-height:
normal"><span style="font-size:12.0pt;font-family:&quot;Times New Roman&quot;,&quot;serif&quot;;
mso-fareast-font-family:&quot;Times New Roman&quot;;mso-ansi-language:EN-US"><a href="file:///C:/Users/HP/Desktop/steemit%20pix/%5bnylon%20%7C%20History,%20Properties,%20Uses,%20&amp;%20Facts%20%7C%20Britannica.com%5d(https:/www.google.com/url?sa=t&amp;source=web&amp;rct=j&amp;url=https://www.britannica.com/science/nylon&amp;ved=2ahUKEwjjweDom-niAhXfVxUIHUEnAAkQFjAbegQIAxAB&amp;usg=AOvVaw2G2litNB-Sbl7cZpo7mjF_)">Nylon
| History, Properties, Uses, &amp; Facts | Britannica.com</a></span></p><p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt;line-height:
normal"><span style="font-size:12.0pt;font-family:&quot;Times New Roman&quot;,&quot;serif&quot;;
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- an overview | ScienceDirect Topics</a></span></p><p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt;line-height:
normal"><span style="font-size:12.0pt;font-family:&quot;Times New Roman&quot;,&quot;serif&quot;;
mso-fareast-font-family:&quot;Times New Roman&quot;;mso-ansi-language:EN-US"><a href="file:///C:/Users/HP/Desktop/steemit%20pix/%5bNylon%20-%20The%20science%20of%20synthetic%20textiles%20-%20Explain%20that%20Stuff%5d(https:/www.google.com/url?sa=t&amp;source=web&amp;rct=j&amp;url=https://www.explainthatstuff.com/nylon.html&amp;ved=2ahUKEwjjweDom-niAhXfVxUIHUEnAAkQFjAgegQIBBAB&amp;usg=AOvVaw0zyNTBLsXoE3EF-zqj-WXN)">Nylon
- The science of synthetic textiles - Explain that Stuff</a></span></p><p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt;line-height:
normal"><span style="font-size:12.0pt;font-family:&quot;Times New Roman&quot;,&quot;serif&quot;;
mso-fareast-font-family:&quot;Times New Roman&quot;;mso-ansi-language:EN-US"><a href="file:///C:/Users/HP/Desktop/steemit%20pix/%5bWhat%20is%20Polyester%20%7C%20What%20is%20Polyester%5d(https:/www.google.com/url?sa=t&amp;source=web&amp;rct=j&amp;url=http://www.whatispolyester.com/&amp;ved=2ahUKEwjN89CJnOniAhX6URUIHQRDC6IQFjAoegQIBBAB&amp;usg=AOvVaw1wZavDwHCN06ogKtjQcNWU)">What
is Polyester?</a></span></p><p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt;line-height:
normal"><span style="font-size:12.0pt;font-family:&quot;Times New Roman&quot;,&quot;serif&quot;;
mso-fareast-font-family:&quot;Times New Roman&quot;;mso-ansi-language:EN-US"><a href="file:///C:/Users/HP/Desktop/steemit%20pix/%5bHow%20polyester%20is%20made%20-%20material,%20manufacture,%20making,%20history,%5d(https:/www.google.com/url?sa=t&amp;source=web&amp;rct=j&amp;url=http://www.madehow.com/Volume-2/Polyester.html&amp;ved=2ahUKEwjN89CJnOniAhX6URUIHQRDC6IQFjApegQIAxAB&amp;usg=AOvVaw3MzLt4XLpRtGXtsFUopWiw)">How
polyester is made - material, manufacture, making, history…,</a></span></p><p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt;line-height:
normal"><span style="font-size:12.0pt;font-family:&quot;Times New Roman&quot;,&quot;serif&quot;;
mso-fareast-font-family:&quot;Times New Roman&quot;;mso-ansi-language:EN-US"><a href="file:///C:/Users/HP/Desktop/steemit%20pix/%5bPolyester%20Fiber%20-%20an%20overview%20%7C%20ScienceDirect%20Topics%5d(https:/www.google.com/url?sa=t&amp;source=web&amp;rct=j&amp;url=https://www.sciencedirect.com/topics/chemistry/polyester-fiber&amp;ved=2ahUKEwjN89CJnOniAhX6URUIHQRDC6IQFjAregQIBxAB&amp;usg=AOvVaw348z5VOYZWFW03yd6N7KJK)">Polyester
Fiber - an overview | ScienceDirect Topics</a></span></p><p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt;line-height:
normal"><span style="font-size:12.0pt;font-family:&quot;Times New Roman&quot;,&quot;serif&quot;;
mso-fareast-font-family:&quot;Times New Roman&quot;;mso-ansi-language:EN-US"><a href="file:///C:/Users/HP/Desktop/steemit%20pix/%5bnylon%206,6%5d(https:/en.m.wikipedia.org/wiki/Nylon)">Nylon 6, 6</a></span></p><p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt;line-height:
normal"><span style="font-size:12.0pt;font-family:&quot;Times New Roman&quot;,&quot;serif&quot;;
mso-fareast-font-family:&quot;Times New Roman&quot;;mso-ansi-language:EN-US"><a href="file:///C:/Users/HP/Desktop/steemit%20pix/%5bWallace%20Hume%20Carothers%5d(https:/en.m.wikipedia.org/wiki/Wallace_Carothers)">Wallace
Hume Carothers</a></span></p><p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt;line-height:
normal"><span style="font-size:12.0pt;font-family:&quot;Times New Roman&quot;,&quot;serif&quot;;
mso-fareast-font-family:&quot;Times New Roman&quot;;mso-ansi-language:EN-US"><a href="file:///C:/Users/HP/Desktop/steemit%20pix/%5bPolytetrafluoroethylene%5d(https:/en.m.wikipedia.org/wiki/Polytetrafluoroethylene)">Polytetrafluoroethylene</a></span></p><p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt;line-height:
normal"><span style="font-size:12.0pt;font-family:&quot;Times New Roman&quot;,&quot;serif&quot;;
mso-fareast-font-family:&quot;Times New Roman&quot;;mso-ansi-language:EN-US"><a href="file:///C:/Users/HP/Desktop/steemit%20pix/%5bCondensation%20polymer%5d(https:/en.m.wikipedia.org/wiki/Condensation_polymer)">Condensation
polymer</a></span></p><p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt;line-height:
normal"><span style="font-size:12.0pt;font-family:&quot;Times New Roman&quot;,&quot;serif&quot;;
mso-fareast-font-family:&quot;Times New Roman&quot;;mso-ansi-language:EN-US"><a href="file:///C:/Users/HP/Desktop/steemit%20pix/%5bPolyethylene%20terephthalate%5d(https:/en.m.wikipedia.org/wiki/Polyethylene_terephthalate)">Polyethylene
terephthalate</a></span></p><p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt;line-height:
normal"><a href="file:///C:/Users/HP/Desktop/steemit%20pix/%5bPolyester%5d(https:/en.m.wikipedia.org/wiki/Polyester)" style="font-family: &quot;Times New Roman&quot;, serif; font-size: 12pt; background-color: rgb(255, 255, 255);">Polyester</a></p>