What Is Nylon and Is It Sustainable?

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Nylon, the world's first entirely synthetic polymer fiber, was introduced by the DuPont company in 1938. Known for its strength, durability, and flexibility, the company originally marketed nylon to women, advertising the elasticity and longevity of nylon stockings when compared to rayon and silk.

Nylon clothing also contributes to microfiber pollution. Recent efforts at reducing the negative environmental impacts of nylon have yielded promising results, with some companies choosing to use recycled nylon in their products, as well as focus on clothing items like puffer coats that are not laundered often and will reduce eventual microfiber runoff from waste water in washing machines.

How Nylon Is Made

Nylon is a polymer, composed of repetitive units of diamines and dicarboxylic acids that contain different numbers of carbon atoms. Most contemporary nylon is made from petrochemical monomers (the chemical building blocks making up polymers), combined to form a long chain through a condensation polymerisation reaction. The resulting mixture can be cooled and the filaments stretched into an elastic thread.

Textile Mill

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Fiber forming polymers are tough, opaque, solids that become viscous and transparent when heated. Filaments can be obtained by pulling threads like taffy from the molten polymer, and, when cooled, stretched to several times their original length. Also known as polyamide, the resulting nylon polymer has a variety of pharmaceutical and industrial applications, with a global market of more than 6.6 million tons per year. Currently, nylon production goes hand-in-hand with petroleum production, but scientists have had promising results replacing well-established petrochemical polymers with bio-polyamides from amino acids.

Environmental Impact

Nylon is a type of plastic, or any material that in some part of manufacturing is capable of flow, and can be extruded, cast, spun, molded, or used as a coating. Most plastics come from synthetic polymers ultimately derived from oil and gas production plus chemical additives.2 As a result, the production process is inevitably tied to the petrochemical industry and has a markedly severe impact on the global climate crisis, even when compared to other industrial polymers.

Conventional nylon is not biodegradable, and improper disposal of products containing nylon can lead to further microplastic contamination. Even when properly disposed of, microscopic pieces of fiber will slough off nylon as it's worn and contribute to waterway plastic pollution. As a result, nylon is not known as a particularly sustainable fabric; however, comparing its environmental harm to other fabrics isn't a simple process.

Scientists have been working to create detailed life cycle inventories and life cycle impact assessments to study the environmental impact of different fibers. Growth or extraction, subsequent choices during production (including carbon offsetting and the use of renewable resources), land use, water use, and biodegradability, are just a few factors at play.



Alternatives to Nylon

 Waterproof Nylon

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Probably the most obvious alternative to nylon is a return to the fibers that it replaced — primarily wool and silk. On the one hand, these materials pose less of an environmental threat because their acquisition is removed from the petrochemical industry. However, raising animals still requires significant amounts of water and other resources, and sheep release methane into the atmosphere. No material can be produced without an environmental impact, and of course there can be animal rights concerns in any situation where an animal is being raised to create a product.

Another potential alternative to nylon is viscose rayon, developed prior to nylon, in the late 1920s. Though it is not considered as durable, rayon comes from cellulose, usually bamboo, meaning that the raw product is biodegradable. That said, many of the production processes can be harmful, particularly if it's chemically and not mechanically processed.

Because more and more manufacturers are experimenting with recycled versions of synthetic fabrics, a close look at the practices of particular brands is probably the best way forward when making ethical choices, while also remembering that any plastic-derived fiber could contribute to microfiber pollution regardless of whether or not it is manufactured from recycled materials.

The Future of Nylon

In recent years, brands such as Eileen Fisher, Swedish Stockings, and Aquafil have begun using recycled nylon in their products. Recycled nylon comes from a variety of sources, including fiber left over from spinning clothing, nylon fishing nets, and plastic bottles. Outerwear and puffer coats that don't need a lot of washing are likely the best strategic use for recycled nylon in the future to help minimize microfiber pollution. In addition, researchers are looking into innovative ways to recycle nylon outside of the realm of fashion, including incorporating nylon fishing nets into fiber-reinforced mortar.

Scientists are also researching polymers to be used in nylon production that don't come from oil and gas extraction. These new bio-based polymers come from metabolic engineering of microorganisms to produce an increasing number of chemicals, materials, and fuels from low-cost renewable resources. While currently there is not a viable replacement for petroleum monomers, highly promising biological blocks of polyamides have been found.1 As the price of petroleum continues to fluctuate, and awareness of the climate crisis increases, it is likely that alternatives to the current components of nylon will be further developed.

Meghan Holmes, January 2021
https://www.treehugger.com/what-is-nylon-and-is-it-sustainable-5086614