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NYLON Chemical Properties, Process and Applications

Author: Cameron Kashani Date started: 13th October 2010

The report has been prepared for ACME Textile Company – technical division

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CONTENTS

EXECUTIVE SUMMARY 2 1 Introduction 3 2 History 3 3 Chemical Properties 3 4 Applications 9 5 Production Process 10 6 Transportation Criteria 11 7 Laws and Regulations 11 8 Conclusion 11 Appendix A – References 12

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Executive Summary Aim – To write an informative report on Nylon. Objectives

- To highlight the history of nylon, its origins and its inventors.

- To describe the chemistry of Nylon, the most common version of nylon and to review

the chemical structure of an example of nylon, its structure and its properties.

- To describe the uses of nylon, both in everyday life and industry.

- To state how nylon is processed and produced.

- To identify nylon's storage requirements and transportation.

- To state any laws and regulations on any of the above in the UK.

- To list the references used in compiling this report.

Writing process Firstly, various sources were found on the internet and from books. The sources were checked for validity. This was done by checking from where the source originated (eg. if the source originated from a company or university then it was valid). Before it was written, the sections of the report were planned. The report was then written with special attention to referencing sources when stating the relevant information. Additional information and Conclusion Information on the transport and delivery and laws and regulations were harder to find. All the aims and objectives were fulfilled.

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1 Introduction This is a report investigating the textile polymer called Nylon. The report will also attempt to give a brief history and informative description of what nylon is. The report will also include references and sources of information.

2 History Nylon is a material that was first produced by a team of scientists, led by "American chemist Wallace Hume Caruthers (1896-1937)" at Du Pont in the 1930s, as described by Hegde et al (2004). According to Hegde et al (2004) it was "the first truly synthetic fiber to be commercialized (1939)."

3 Chemical Properties Nylon is an artificially produced "thermoplastic" polymer (Hegde et al [2004]) with several useful properties. As explained by Hegde et al (2004) it is produced by reacting a diamine with a dioic acid.

The most commonly used version of nylon is 6-nylon as Aharoni (1997) explains in his book. To demonstrate the chemistry of polymers, however, 6,6-nylon will be used as an example. 6,6-nylon involves two monomers; "hexamethylenediamine (1,6-diaminohexane, H2N-(CH2)6-NH2)" and "adipic acid (Hexane-1,6-dioic acid, HOOC-(CH2)4-COOH)" which Cotton (2010) states in his report. The structures of 6,6-nylon's two monomers are shown in the table (page 4).

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Picture Description

The chemical structure of hexamethylenediamine. Picture by ChemBlink (2010).

The chemical structure of adipic acid. (picture: Biological Magnetic Resonance Data Bank 2010).

Step of the mechanism What occurs in the mechanism

1

Oxygen from one adipic acid molecule, donates a pair of electrons to a hydrogen atom of a hydroxide group in another adipic acid molecule. This causes the oxygen atom to become protonated, making the carbon atom it is bonded to vulnerable to nucleophilic attack.

A table showing the mechanism of the production of 6,6-nylon. All the information is taken from the diagrams

which are taken from the Polymer Science learning center (2010).

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2

A nitrogen atom from the hexamethylenediamine atom donates an electron pair to the slightly positive carbon atom on the protonated adipic acid molecule.

3

The hydrogen atom bonded to the protonated oxygen atom, donates an electron pair to the oxygen atom, which then donates an electron pair to the carbon atom, which then donates an electron pair to the hydroxide group. The hydroxide group then donates an electron pair to a hydrogen atom, which donates an electron pair to the positive nitrogen atom. This results in a "dimer" being produced as well as a molecule of water and a hydrogen ion.

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The bonds between the chains are hydrogen bonds as explained by the Polymer Science Learning Center (2010). These bonds determine nylon's properties, (especially "strength" [Lagasse 2008]). How the polymer chains are arranged also determines nylon's properties. There are two types of structures in polymers, as explained by Rosato (1997). He details how polymers can be crystalline or amorphous. In nylon, the long chains can align (crystalline). Any other structure, as Rosato (1997) explains, is amorphous.

The final product is shown in the diagram (6,6 – nylon).

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A table taken from Rosato’s book

(1997).

A list of nylon’s properties from the CES Edupack (2010).

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The "non-equilibrium melting point of 6,6-nylon is around 255-60°C" as Aharoni (1997) states in his book. According to Aharoni (1997), this is determined by the number of "CH2

units in the diamine and the dicarboxylic acid components". Nylon is also recyclable. Here is nylon's recyle mark (CES Edupack [2010]). As the CES Edupack (2010) details, during primary production, 5.5 – 5.6 kg of CO2 is released per kg of nylon produced.

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4 Applications Cotton (2010) intimates that, because of its corrosion free nature, nylon was used in toothbrushes (as shown in the advertisement). Information from the list is from the CES Edupack (2010)

- Light duty gears - Bushings - sprockets and bearings - electrical equipment housings - Lenses - Containers - Tanks - Tubing - furniture casters - plumbing connections - bicycle wheel covers - ketchup bottles - Chairs - toothbrush bristles - Handles - Bearings - food packaging - Ropes

Because of the "extreme toughness, strength and peculiar ability to be formed into fibres" (Adams 1939), nylon is ideal for such applications as handles and chairs, which take loads, or for ropes and toothbrush bristles, which require fibres.

A “Dr. West’s” nylon toothbrush

advertisement.

Picture taken from Cotton’s nylon

report (2010).

A list of nylon uses directly from the

CES Edupack (2010).

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5 Production Process - Description of flow chart 1. Processing of raw materials. 2. The monomers are "combined". They are mixed together (not reacted, that occurs in the reaction vessels). 3. The nylon salt is dissolved in water. It is possible to infer that this makes the salt easier to transport. 4. "In the spinning mill, salt is heated in evaporators to obtain a concentrated solution." This could be to increase the reaction rate between the "two chemicals". 5. Reaction vessels use heat to combine the "two molecules of the two chemicals into large chainlike molucules known as 'linear superpolymers'". 6. The "linear superpolymers" move around a casting wheel. A spinneret removes strands of nylon from the molten nylon which are "air-cooled to form filaments".

Raw materials

Hexamethylene diamine

Adipic acid

Nylon salt

Nylon solution

3

4

A flowchart describing the production of nylon.

All the information from this flowchart is from

the narrow fabrics website (2010).

Concentrated

solution.

1

“Linear

Superpolymers” 5

6,6-Nylon

filaments.

6

2

All information from the description above is from the narrow fabrics website (2010).

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A more complex and in depth flow chart is shown below.

6 Transportation Criteria Inchem (2010) states that "crystalline AH salt" (which it says is "produced in closed systems by mixing adipic acid and 1,6-hexanediamine in water at approx. 90 °C") is transported at 90 °C "on tank trucks, ships or tank wagons" in "stainless steel tanks". It also states how the tanks are insulated as to ensure the AH salt remains a liquid.

7 Laws and regulations Direct Plastics (2004) states that there is "no warning necessary" under "EU guidelines". Under "potential risks", the website explains that nylon is not harmful. Direct Plastics (2004) also states that 6,6-nylon can be recycled and "if no use is possible, product waste can, in accordance with official local regulations, be mixed with household waste or incinerated in an appropriate place". The "conditions to avoid" are also stated; apparently temperatures above 300°C results in thermal decomposition which can produce toxic gases (e.g. carbon monoxide and nitric oxide).

8 Conclusion The chemistry, properties and production of nylon are far easier to find than the laws and transportation of nylon. However, I feel I have succeeded in fulfilling my aims and objectives for this report.

A flow chart from the Pall

corporation (accessed 2010).

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Appendix A – References "n-Nylons: Their Synthesis, Structure and Properties"; pages 63, 170 Shaul M. Aharoni (1997) "The Columbia Encyclopedia Sixth Edition"; Paul Lagasse (2008) " http://www.narrow-fabrics-manufacturers.com/articles/nylon6-6.html"; Online B2B Marketplace narrow fabrics (consulted 13/10/2010 at 17:21) "http://www.engr.utk.edu/mse/Textiles/Nylon%20fibers.htm"; Raghavendra R. Hegde, Atul Dahiya, M. G. Kamath (Monika Kannadaguli and Ramaiah Kotra) University of Tennessee Knoxville (consulted 14/10/2010 at 11:48, last updated April 2004) "http://www.chm.bris.ac.uk/motm/nylon/nylonv.htm"; Simon Cotton, Uppingham School, Rutland, UK from the University of Bristol school of chemistry (consulted 14/10/2010 at 12:29, last updated 01/06/2010) " http://www.chemblink.com/products/124-09-4.htm"; ChemBlink (consulted 14/10/2010 at 13:20)

"http://www.bmrb.wisc.edu/metabolomics/mol_summary/?molName=Adipic_acid"; Biological Magnetic Resonance Data Bank (consulted 15/10/2010 at 12:24)

"http://pslc.ws/macrogcss/nysyn.html"; Polymer science learning center (consulted 23/10/2010 at 16:46) "http://pslc.ws/macrog/lab/lab01.htm"; Polymer science learning center (consulted 24/10/2010 at 21:22) "www.nap.edu/html/biomems/wcarothers.pdf"; National academies press; National Academy of Sciences: biographical memoir of Wallace Hume Carothers by Roger Adams (presented at an annual meeting 1939) (consulted 24/10/2010 at 21:29) "Plastics Processing Data Handbook (2nd Edition)" pages 59, 60 accessed through Knovel.com (consulted 27/10/2010 at 19:54); Author: Dominick Rosato (1997) CES Edupack 2010; MaterialUniverse: Polyamides (Nylons, PA) (accessed 29/10/2010 at 22:57) "http://www.pall.com/pdf/PPG3a.pdf"; Pall corporation; Nylon 66 Fiber Production (accessed 30/10/2010 a 14:00) "http://www.inchem.org/documents/sids/sids/3323533.pdf"; INCHEM Chemical Safety Information from Intergovernmental Organizations (accessed 30/10/2010 at 15:44) "http://www.directplasticsonline.co.uk/pdf/HSE_Nylon_66.pdf"; Direct Plastics (written 15/04/2004) (accessed 30/10/2010 at 16:37)

Word count: Around 1090 words excluding references, subtitles, tables,

the title page, flowcharts and this sentence.