Introduction
Thesis Statement
Nylon, which is a generic polymer, is the most widely used and the most important class of plastics. In addition, it is regarded as the first ever commercially viable polymer. The extensive use of the polymer is associated with its unique characteristics. The various characteristics that make this polymer to be the most widely used include, among others, its ability to be remodeled into different shapes, forms, and textures. The capability is linked to the fact that when exposed to heat, nylon melts as opposed to burning. The ability to melt makes it possible to reproduce the polymer over and over again.
In this report, the author looks at the various aspects of nylon. Issues addressed in this report include, among others, production of nylon, characteristics of the polymer, as well as its uses and various applications. In addition, the report addresses the safety of the polymer as far as human health is concerned. The report will make a comparison between the two most common versions of nylon. The two are nylon 66 and nylon 6.
General Background Information
The general background provides information on the various terms used to describe nylon, the history of nylon, a comparison between nylon and other natural materials, such as cotton and silk, and the standards set aside to regulate the production of nylons. Plastic is the term used to refer to any moldable synthetic or partially synthetic and organic solid.1 The material is natural and, in most cases, it is derived from petroleum products. Nylon, which is also commonly referred to as polyamide, is the most used form of plastic. Over the years, researchers in this field have described it as the most economically viable of all plastics. According to these researchers, there are different forms of nylons used in various ways today. The two major forms of nylons are nylon 6 and nylon 6,6. Though the two possess physical and chemical properties that almost similar to one another, nylon 6 is regarded as tougher than nylon 6,6. In addition, nylon 6 possesses higher tensile strength compared to nylon 6,6. As a result of this, nylon 6 is widely used compared to nylon 6,6.
The discovery and development of nylon is traced back to 1929. The discovery is associated with the introduction of the first publication describing the polycondensation process. According to analysts, the process is the basic principle behind the synthesis of nylon. The discovery of the polycondensation process served as the basis of nylon production. The discovery inspired interested parties and companies to carry out more research to improve and refine the process. In 1931, DuPont, a company based in the United States of America, developed the first ever form of nylon. The nylon was branded by experts and the developers as “66.” The name ‘nylon 66’ was inspired by its molecular structure. In 1938, I.G. Farben, an industry based in German, produced nylon “6” through the polymerization of caprolactam.2 DuPont embarked on commercial production of nylon in 1939. Since 1939, nylon continues to be the most commercially viable polymer.
Nylon has over the years found many applications in the society. As already mentioned in this report, the polymer is the most widely used artificial material in the society today. The polymer is commonly used in the manufacture of storage materials, such as tanks and containers. In addition, the polymer is widely used in the textile industry. As a result, the production and application of nylon has influenced almost every aspect of human life in contemporary society. To this end, the polymer provides clothing and employment to many people across the world.3 Many people are engaged in the research and production of nylons. The final product is used in manufacturing clothes and other products used by humans in the society.
As already indicated in this report, the textile industry is the largest consumer of plastics in the world today. The widespread use of nylon in this industry was largely influenced by the inability of silk and cotton to meet the increasing global demand for textile fibers. The shortcomings of silk and cotton as far as addressing the demand is concerned are attributed to the long duration of time associated with the production of the two materials. Silk and cotton are biological products, which means that it takes time before they are planted, harvested, and processed into clothing materials. On the contrary, nylon is an artificial material. What this means is that it is possible to produce nylon on demand.4 In the recent past, the standards established to ensure the production of high quality and safe nylon have significantly changed. To this end, it is noted that the decitex of nylon yarns produced in industries should range between 1100 to 66000dc. In addition to this, the length of the cones used in rolling the nylon yarns should range from 100 to 250 millimeters.
Background Information
Overview
As a polymer, nylon has various applications in the society today. However, there are areas where the application of this polymer is limited. In this section, the report analyzes the various applications of this polymer, as well as the areas where its application is limited.
Uses of Nylon
The use of nylon, just like that of any other product, depends on its physical and chemical characteristics. Some of the most important characteristics that make nylon a unique product include luster variation, durability, and resistance to abrasion. In addition, nylon is resistant to destruction by chemical agents, insects, and animals. Another characteristic of nylon that makes it a unique product is its ‘excellent and specific strength’.5 Researchers and scientists have relied on these properties to use nylon in various processes. In addition to the properties mentioned above, both nylon 6 and nylon 6,6 are versatile. It is easy to mold the two into sheets, bristles, fibers, and filaments, which are widely used in the society.6
Nylon 6 is more widely used compared to the other forms of nylon. The plastic has a unique capability of producing fabric without the need for weaving. The fabrics produced are significantly light and strong, making increasing their resistant to wear and tear. As compared to nylon 6,6, it is easier to dye nylon 6 at high pressure. In addition, nylon 6 has made it possible to produce translucent clothing materials. The ability to produce translucent materials is associated with nylon 6’s high luster variation.7 Both nylon 6 and nylon 66 are used in the production of waterproof attires. As a result, they play a crucial role in the production of waterproof clothing materials. In addition, the high melting point of these polymers makes it possible to iron clothes made of nylon.
However, nylon fabrics expose individuals to various risks, such as burns. Though nylon has a relatively high melting point, the plastic places its user at the risk of getting burnt in case of a fire accident. Given the polymers’ high melting point, they may cause serious burns to the user. However, the waterproof nature of nylon is an advantage that may cancel out most of its shortcomings. As a result of their waterproof nature, nylon fabrics are resistant to most chemicals. Most protective clothing materials are made of nylon, which protects the wearer from getting chemical burns. In addition, other features, such as toughness and high tensile strength, protect the fabrics from getting destroyed by insects, animals, and other natural factors. The property increases the durability of nylons in comparison to other fabrics, such as those made of silk and cotton.8
Nylon is a very important matrix component in composite materials. The plastic is reinforced with glass fibers and other carbons to create harder materials that can withstand more stress compared to nylon in its pure form. The capability of being used as a matrix material owes to the fact that nylon is highly adhesive to a variety of surfaces. Nylon 6,6 is considered to be more appropriate in the manufacture of composite materials compared to nylon 6. The reason for this is that nylon 6,6 is more flexible compared to nylon 6. The high density of the resulting composite materials makes them suitable for the production of hard components. A classical example of how nylon is used in the manufacture of composite materials is in the production of high quality windscreens.
Moreover, nylon is commonly used in the manufacture of industrial yarns. The yarns are made up of long strands of nylon. They are especially used in weaving or in manufacturing threads. Yarns are manufactured to ease the process of storing and handling nylons and other synthetic materials.9 From a single yarn, the user can come up with a variety of shapes and sizes of nylon, which is then adjusted to perform the intended task. The capability of both nylon 6 and nylon 66 to be rolled into yarns is attributed to their flexibility and high resistance to fatigue. The toughness and high tensile strength of these polymers is important as it ensures that the yarns remain intact and are resistant to wear and tear as the nylon is rolled out of the yarn during industrial processes. The ability of the polymer to stick to rubber comes as an added advantage since it makes it easy to roll the plastic over rubber. The capacity to blend with other polymers, such as polythene, makes it possible to produce cheaper yarns without necessarily having to interfere with the quality of the yarn produced.
The increased industrial use of both nylon 6 and nylon 6,6 has, however, raised serious safety and health concerns. Considering that nylon is non-biodegradable, the polymer poses serious threats to humans and other members of the ecosystem. The plastic persists in the environment for long periods of time if not properly disposed of. It may suffocate animals and plants in the ecosystem, which may lead to their death. What this means is that nylons interfere with population balance in the ecosystem.10 In addition, burning nylons gives rise to harmful gases, which pollute the environment.
Nylon is used in the manufacture of most artificial objects today. The material is easy to remodel, which means that it is possible to mold it into different shapes and sizes. In addition, it is easy to dye nylon, especially nylon 6. What this means is that it is possible to produce nylon items with different colors, depending on market demand. The plastic is, for instance, used in the manufacture of toys and other recreational objects, such as skate-boards. There are unique characteristics that give nylon this capability. For example, unlike other materials, nylons melt (instead of burning) when exposed to heat.11 Melting makes it possible to remodel the polymer to the desired shape and size. The ability to reproduce these plastics has significantly lowered the cost of nylon products, since it is possible to recycle the plastics over and over again. In addition, the ability to recycle plastics has made it possible to reduce environmental pollution resulting from nylons. The elasticity and high tensile strength associated with the plastic enhances the durability of the resulting objects since they are resistant to breakages, thus posing less danger to the users and other organisms in the environment. However, the artificial objects may lead to pollution in cases where their disposal is not controlled. Burning the plastics pollutes the air, leading to serious health complications in humans and other living organisms.
Furthermore, nylons are widely used in the automotive industry. Here, nylon 6 is more widely used compared to nylon 6,6 due to its toughness, higher specific strength, as well as its ability to resist heat. Nylon 6 is used in the manufacture of tough engine parts and wheels. The plastic is, for instance, used to manufacture engines’ tubular components, such as oil passages.12 Nylons are cheaper compared to metal components, which considerably lowers the cost of automotives. Nylon 6 is elastic and has high tensile strength, which means that it does not break easily, even when subjected to considerable amounts of force.
Just like nylon 6, nylon 6,6 is also used in the automotive industry. However, it is used in the manufacture of softer parts compared to nylon 6. They include such parts as casings and motor vehicle airbags. The elasticity and high elongation capabilities of nylons support this functionality. In water transport, nylon screws are necessary in making the vessels airtight and water tight. In addition, the use of nylons in water vessels makes them lighter and water proof. The use of nylon has a bearing on the cost of automotives. Nylon, which is a cheaper commodity compared to metal, considerably reduces the cost of automotives. The water proof nature of nylons increases the safety of the automotives.13 Airbags and nylon casings enhance the safety of the automobile, increasing the chances of survival in the event of an accident.
Both nylon 6 and nylon 6,6 are effective insulators in electrical and mechanical parts. The capability is attributed to the fact that the plastic is a poor conductor of both heat and electricity. Electric wires are coated with nylon to prevent accidents. The flexibility of the plastic is of great importance as it enhances the ability to bend electrical components around the electrical device. Nylon casings are used to cover electrical devices, making such devices user friendly. The plastic is also water proof, preventing the entry of moisture that would otherwise destroy the devices or even put the users at risk of electric shock. Nylon 6,6 is mostly used in coating wires due to its flexibility. Nylon 6, on the other hand, is mostly used in casings as a result of its toughness, as well as it high specific strength.14 Nylon 6,6’s ability to resist abrasion is critical as it ensures that inner components, which are delicate, are protected from damage.
As already indicated, nylons are bad conductors of heat. As such, they are used as insulators. The plastics are particularly used in manufacturing cooking utensils, such as pans, where it is used to coat the handles. The polymer’s high melting point allows it to withstand high temperatures of over 200 degrees centigrade. The temperatures are far higher than those used in cooking, which protects the individuals from getting burnt. In manufacturing plants, nylon is used to insulate machine parts. The insulators protect individuals working in the plants from getting exposed to excessive heat produced by machines, which considerably reduces the occurrence of burns. Robots, which are today commonly used in the manufacturing industry, are also made using plastics. They are used to carry out tasks that cannot be performed by human beings.15 The high melting point of this polymer means that it is possible to use it in high temperatures unbearable to humans.
Nylon 6 is used in the manufacture of hard machine parts. What makes this possible is the toughness of the polymer, its high melting point, as well as its relatively high specific strength compared to nylon 6,6. The plastic is also used in the manufacture of tubular machine parts. Use of nylon makes it possible to tighten oil passages, which averts instances of leakages that will otherwise cause massive losses to the industries, or even cause fire accidents. The elasticity of the plastic provides for a more reliable fastening of parts. The ability is associated with the polymer’s excellent elasticity and elasticity recovery. Conveyor belts used in manufacturing plants are made from nylon owing to its elasticity and high resistance to abrasion. The use of nylon in manufacturing plants is more extensive compared to the use of any other group of plastics. Though nylon is not as tough and as reliable as metal components, its use in the manufacture of machine parts has persisted over the years.16 The ability of nylons to melt at high temperatures, as opposed to burning, is vital in reducing instances of fire accidents. However, nylons cannot withstand high levels of heat compared to metal parts, which makes researchers to question their safety in industrial processes.
Both nylon 6,6 and nylon 6 are used in the manufacture of a variety of household equipments and materials as a result of their versatility. Most household brushing tools are manufactured from nylon. Nylon 6 is especially popular in the manufacture of bristles used in scrubbing brushes, as well as tooth brushes. The capacity to be used in the manufacture of bristles owes to its flexibility, its soft texture, and its high specific strength compared to other plastics. Other household products manufactured from nylon include carpets, toys, and food and water storage containers.
The durability of nylons, as well as their high resistance to abrasion, is vital in the manufacture of quality products. High resistance to destruction caused by insects, fungi, and animals has a bearing on the durability of nylon products. Most domestic electrical appliances are made from nylon casings. Analysts say that nylons affect each and every living organism, either directly or indirectly. Other areas where the plastic is widely used include in military operations, where nylon is used in the manufacture of gun frames and parachutes owing to its high specific strength.17 Nylon 6,6 is lighter and more flexible compared to plastic 6. What this means is that nylon 6,6 is widely used in the manufacture of parachutes, bullet proof vests, and other protective gear. Nylon 6, on the other hand, is used in the manufacture of hard armor components, such as gun frames, military water bottles, and bags.
Areas Where the use of Nylon is Limited
Nylon, just like other materials, has various disadvantages associated with it. Like other plastics, nylon has poor resistance to fatigue compared to its supplements, such as metals and wood. As such, nylon is only used in the manufacture of low and medium stress components. The property has seen most engineers resorting to the use of wood cores in skis. In addition, the plastics have lower specific strength compared to wood and metal. As such, they are considered as a poor source of support. It is because of such properties that nylon is not used in such high stress areas as the construction industry. The flexibility of the material is another disadvantage since the plastic is easily bent and cannot be used to provide firm support. It can only provide firm support if it is reinforced with other materials, such as carbon and glass.
Furthermore, nylon cannot be used in the construction of high stress automotive components. Most motor vehicles and other automotives’ manufacturers prefer using metallic components that can withstand high levels of pressure and stress. However, it is possible to reinforce nylon with other materials, such as glass fibers, to make such motor vehicle components as windscreens. Though reinforcing strengthens and toughens the polymer, the objects manufactured from these reinforced materials are still susceptible to breakages when exposed to considerable amounts of stress.18 However, nylon increases the safety of such materials since it prevents the fragmenting of glass in the event of accidents, protecting the user from cuts.
The polymer’s melting point limits its use in processing plants since it cannot withstand high temperatures compared to metals. Many manufacturing plants carry out processes that involve high amounts of heat, which may at times exceed 400 degrees centigrade. At these temperatures, the plastic is in the form of a viscous fluid.19 However, the development of nylon improvement processes, such as Reaction Injection Molding, has led to the production of ‘more physically tough’ nylons. The nylon produced in this process is superior in appearance, increasing the value of the products manufactured using the material.
State-of-the-Art Proposals to Improve the Quality of Nylon
Researchers have over the years come up with measures to deal with the various shortcomings of nylons in an attempt to improve the plastic. A good example of the processes developed to improve the quality of nylons produced is the Reaction-Injection Molding. The process is similar to the injection molding technique, but differs due to the fact that the reaction-injection molding requires a thermosetting polymer. The curing reaction takes place inside the thermosetting polymers. The two components used in the manufacture of the plastic are injected into the mold with the help of a mixer. The process is carried out under very high pressure. The technique used in the manufacture of nylons involves the reaction between a carboxylic acid and a molecule containing an amine group.20 The carboxylic acid provides hydrogen vital in the formation of hydrogen bonds. The mixture is allowed to sit in the mold until it has cured and expanded adequately. The method is relatively expensive compared to other techniques of producing nylons.
Researchers have proposed that increasing the clumping force will boost the quality of the nylon produced. Increasing the clumping forced in curing nylon will lead to the production of highly compact nylon foams. Compact molds are harder and heavier than conventional plastic as a result of their high density. In addition, ‘compacting’ the plastic will reduce its intermolecular space, increasing the polymer’s specific strength. The process will reduce the risk of breakages, increasing the application of nylons in various industries, such as the construction sector.21 Reduced intermolecular space will also raise the melting point of the nylon produced, making it possible to use the product in a wide range of temperatures.
The other possible means of improving the quality of nylon is through further polymerization of the amide chains. Further polymerization involves the introduction of more hydrogen bonds, which will in turn increase the attraction strength between the chains of the polymer.
Prospectus and Discussion of the Measures to Improve the Quality of Nylon
Overview
The measures to improve the quality of these polymers, which are discussed above, are criticized by various researchers. They are criticized in light of the various obstacles hindering the production of state-of-the-art nylons.
A Critique of the State-of-the-Art Proposal
Many critics have over the past become part of the discussion surrounding the viability of nylon compacting as a way of improving the quality of this polymer. Many have felt that the compacting process is not practical since molecules used to build the nylon are linked together by chemical bonds. Interfering with bond formation translates to interference with the polymer’s chemical properties. The interference may lead to the formation of a material that is totally different from nylon. Normally, nylons are made up of chains of amide molecules linked together. The amide chains are parallel and are attached to each other. ‘Compacting’ the nylon will break the hydrogen bonds, interfering with the arrangement of the chains and changing the properties of the nylon. There is a need to come up with a way of ‘compacting’ the monomers without interfering with the nylon’s chemical composition. Such a process is a promising means of improving the plastic. Further polymerization of amide chains is a promising process as far as improving the quality of nylons is concerned.22
Obstacles Hindering the Development of Next Generation Nylons
The arrangement of amide chains remains the major hindrance in the development of the next generation of nylons. It is important that the chains remain parallel to each other so as not to change the chemical properties of the nylon. To achieve this, the hydrogen bonds interlinking the chains must be maintained. Plastic engineers continue to carry out research to determine the most promising means of producing high density plastic foams without interfering with the chemical composition of the plastics.23 There are almost zero chances of compacting monomers since they are repeating units. Chemically interfering with one unit will ultimately affect the entire nylon mass. Therefore, further polymerization of the amide chains to improve the quality of nylon is the most promising means of producing next generation nylons.
Conclusion
Nylon is the most widely used and the most important class of plastics. It is regarded as the first ever commercially viable polymer. The extensive use of the plastic is associated with its unique characteristics that distinguish it from other plastics. Two major types of nylon exist in the world market today. The two are nylon 6 and nylon 6,6. The two forms of nylons possess almost similar characteristics, though nylon 6 is regarded as superior to nylon 6,6 as a result of its high tensile and specific strengths. Nylon 6 is also tougher compared to nylon 6,6, making it more resistant to abrasion.24 As a result, objects manufactured using the plastic are more durable than those manufactured using nylon 6,6. On its part, nylon 6,6 is softer and more flexible compared to nylon 6.
However, just like other materials, nylon has several disadvantages. It is only used in the manufacture of low and medium stress components. Researchers have made efforts to come up with measures aimed at improving the quality of nylon. To this end, there are various processes aimed at improving the quality of nylon. The reaction injection molding is such a technique.25 As a result, nylon that is harder and lighter than the conventional polymer is produced at relatively low costs and less time.
Bibliography
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Bjarnason, Brown. “Millimeter-Wave, Terahertz, and Mid-Infrared Transmission Through Common Clothing.” Applied Physics Journal 85, no. 4 (2004) : 519-523.
Chun, Yang. “Most Plastic Products Release Estrogenic Chemicals: A Potential Health Problem That Can Be Solved.” Environmental Health Perspectives 12, no. 1 (2005) : 25-40.
Fenichell, Stephen. Plastic: The Making of a Synthetic Century. New York: Harper Business, 2006.
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Jellinek, George. “Kinetics and Mechanism of HCN Evolution from Nylon 66 and Design of Apparatus.” J. Polym 20, no. 1 (2002) : 85–101.
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End Notes
1. Peter Watson, A Terrible Beauty: An Intellectual History of the 20th Century (London: Weidenfeld & Nicolson, 2001), 21.
2. Adrian Kinnane, DuPont: From the Banks of the Brandywine to Miracles of Science (Baltimore: Johns Hopkins University Press, 2002), 42.
3. Yang Chun, “Most Plastic Products Release Estrogenic Chemicals: A Potential Health Problem That Can Be Solved,” Environmental Health Perspectives 12, no. 1 (2005) : 27.
4. Kinnane, DuPont, 43.
5. Ibid.
6. Kaneyoshi Ashida, Polyurethane and Related Foams: Chemistry and Technology (London: CRC Press, 2006), 56.
7. Brown Bjarnason, “Millimeter-Wave, Terahertz, and Mid-Infrared Transmission Through Common Clothing,” Applied Physics Journal 85, no. 4 (2004) : 522.
8. Schrieffer Heeger, “Solitons in Conducting Polymers,” Reviews of Modern Physics 60, no. 3 (2001) : 782.
9. Bjarnason, “Millimeter-Wave,” 520.
10. Stephen Fenichell, Plastic: The Making of a Synthetic Century (New York: Harper Business, 2006), 17.
11. Elias Hans-Georg, Plastics: General Survey (London: Weinheim, 2005), 34.
12. Fenichell, Plastic, 18.
13. Hans-Georg, Plastics: General Survey, 35.
14. Alan Weisman, The World Without Us: Nylons (London: HarperCollins, 2010), 33.
15. George Jellinek, “Kinetics and Mechanism of HCN Evolution from Nylon 66 and Design of Apparatus,” J. Polym 20, no. 1 (2002) : 85
16. Chun, “Most Plastic Products,” 30.
17. Jellinek, “Kinetics and Mechanism,” 88.
18. Kinnane, DuPont, 43.
19. Watson, A Terrible Beauty, 22.
20. Ashida, Polyurethane, 58.
21. Bjarnason, “Millimeter-Wave,” 520
22. Heeger, “Solitons in Conducting Polymers,” 784.
23. Weisman, The World Without Us, 35
24. Fenichell, Plastic, 18.
25. Hans-Georg, Plastics: General Survey, 35.