Presentation By
Mr. Devang Mehta (80)
Mr. Ranjit Makwana (79)
Mr. Harsad Kothiya (78)
Contents:
1. Introduction
2. Reflections of the Nylon 6-6 History
3. Synthesis
4. Experimental procedure
5. Application
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1.1 Basic Information
Monomers : Dicarboxylic Acid, Diamines
Polymerization : Polycondensation Reaction
Major Uses : Mainly In Manufacture Of
Fibres
Structure :
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1.2 Why Nylon 6 ?
• Why Nylon 6-6 (Polyamide 6) ?
• A black box embodied in our lives
• Wide influence on society
• Change of relation between lab and commercial industry
• More recent innovation
• very well documented
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1.3 Utilization of Nylon 6
The utilization of Nylon 6:
Textile industry (“wash and wear”)
Carpets
Outdoor clothing (inc. tents, backpacks etc)
Tires, etc…
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1.4 Properties of Nylon 6-6
Chemical & mechanical properties of Nylon 6:
High tensile strength (stretchable without deformation)
Excellent chemical resistance
High mechanical strength and heat resistance
Easy to process
Can be dyed easily
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1.5 Properties
• Properties
•
•
•
•
•
•
Glass transition temperature :
Melting temperature :
Amorphous density at 25oC :
Crystalline density at 25oC :
Molecular weight of repeat unit :
Typical Physical Properties
47oC.
220oC.
1.084 g/cm3.
1.23 g/cm3.
113.16 g/mol.
• Repeat Unit
•
• C6H11ON
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2 Methodology
Methodology:
Brief introduction to the three different views on history:
 The inventor (W. Carothers)
 The company where he conducted the research in his lab
(Du Pont)
 The global perspective
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2.1 History 1
Wallace H. Carothers (1896-1938)
Genius chemist, several degrees
Conducted research at industrial company (Du Pont)
Conducted research to find a molecule as large as possible
In the beginning he was free to chose his topic, later on he was
oriented by Du Pont
His colleague realized that nylon could be drawn into fibre (1934)
Suffered from depression and committed suicide
Science and Corporate Strategy – Du Pont R&D (1992)
Polymers – The Origins & Growth of a Science (1995)
Massachusetts Institute of Technology http://www.mit.edu (2002)
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2.2 History 2
Du Pont (established 1802)
Wanted to have a research lab as their “commitment to
scientific discovery as the key to future success”
Lured away Carothers from Harvard university
Carothers was free to “do pure basic research”
Du Pont wanted to develop a synthetic fibre that could
replace silk
Nylon invented by Carothers in 1935
In 1938, public announcement of nylon as “the first manmade organic textile fabric prepared entirely from new
materials from the mineral kingdom”
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2.3 History 3
The Global View
Despite the Great Depression, Carothers’ Lab´s funding
was never reduced
By 1931 silk was getting expensive and harder to find due
to political and trade troubles with Japan
Du Pont was urged by the US government to make Nylon a
reality as quick as possible
Nylon was a potential as a vital war material
During war Nylon replaced Asian silk and supplanted
cotton
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3.1 Synthesis
Synthesis
Nylon 6 begins as pure Caprolactam. As caprolactam has 6
carbon atoms, it got the name Nylon-6.
When caprolactam is heated at about 533 K in an inert
atmosphere of nitrogen for about 4-5 hours, the ring breaks and
undergoes polymerization. Then the molten mass is passed
through spinnerets to form fibres of Nylon 6.
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3.2 Synthesis
During polymerization, the peptide bond within each caprolactam
molecule is broken, with the active groups on each side re-forming
two new bonds as the monomer becomes part of the polymer
backbone. Unlike nylon 6,6, in which the direction of the amide
bond reverses at each bond, all nylon 6 amide bonds lie in the
same direction (see figure: note the N to C orientation of each
amide bond). Nylon 6 therefore resembles natural polypeptides
more closely; in fact, caprolactam would become an amino acid if
it were hydrolyzed. This difference has little effect on the
polymer's mechanical or chemical properties, but is sufficient to
create a legal distinction.
Nylon 6 (above) has a structure similar to Nylon 6,6 (below).
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4.1 Experimental Procedure
Experimental Procedure :
10 g of e - caprolactam are placed into a 25 mL beaker. Using a
glass rod a small piece of sodium (approx. 0.01 g) is pressed into
the caprolactam.
The melting of the mixture occurs with reduced burner flame.
Afterwards the liquefied materials are heated to boiling. The
deep brown molten mass is cooled down for 5 minutes.
The mixture will become much more viscous.
Fibers are drawn by dipping a glass rod into the polymer and
rapidly drawing out the solidifying material of the beaker.
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4.2 Discussion
Discussion:
1)The induction of the lactam polymerization occurs in two steps.
Caprolactam first reacts with Na to give lactam anion.
2)In the second step of the initiation process, the lactam anion (the
activated monomer) attacks the carbonyl carbon of caprolactam
and adds to it. Ring-opening leads to the formation of N-caproyl
caprolactam anion.
3)Thus another species is generated that can react again in the
same manner. This happens over and over to produce a long
chain of perlon .
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4.3 Reaction
Anionic, ring-opening polymerisation
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5.1
Applications
Applications
Nylon 6 is used as,
 Thread in bristles for toothbrushes and Surgical sutures
 Strings for acoustic and classical musical instruments, including guitars,
violins, violas, and cellos.
 It is also used in the manufacture of a large variety of threads, ropes,
filaments, nets, and tire cords, as well as hosiery and knitted garments.
It can also be used in gun frames, such as those used by Glock, which are
made with a composite of Nylon 6 and other polymers. It has the potential
to be used as a technical nutrient.
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