I. Introduction
Hook:
In recent decades, a rise in concerns over plastic pollution has inspired a global trend toward more sustainable practices. With increasing knowledge about pollution and its environmental consequences, people have become more aware of plastic’s long-term effects in the natural world. With millions of tons of waste sitting in landfills, seas and rivers, the biodegradability of materials such as nylon has become a focal point of environmental activism. Does nylon decompose or is it part of the growing global waste problem?
Relevance:
As a ubiquitous product from clothing to auto parts, nylon is a vital part of everyday life, and a massive source of the ever-increasing environmental burden. Nylon, originally invented as a synthetic replacement for silk in the 1930s, revolutionised textile and industrial production because of its strength, malleability and durability. Yet in the face of our “throwaway” culture, it’s vital to understand one question: will nylon, like most synthetic polymers, naturally decompose or will it keep clinging on forever and feeding the ecological crisis?
Purpose:
In this blog, I want to clear up some misconceptions about nylon’s biodegradability, why it isn’t naturally biodegradable under the majority of environmental conditions, and the wider environmental implications. We hope by breaking down the science behind nylon and delving into its environmental impacts, we can shed some light on why nylon contributes to the waste problem around the world and how we can change it.
Also Read : Recycled Nylon
II. What is Nylon?
Definition
Nylon is a synthetic polymer derived from petrochemicals and is one of the most common materials today. It was the first synthetic fibre entirely made from petrochemicals, invented in the early 20th century by Wallace Carothers and his colleagues at DuPont in 1935. Because nylon is a thermoplastic polymer, it softens upon heating, making it useful for a broad range of industrial and consumer uses. It is well-known for its hardness, flexibility, abrasion resistance, and general versatility and has been adopted in various fields.
Types of Nylon
Nylon has grades that are specifically tailored to specific uses, and are usually classified by the monomers that make up the chemical formula. The two most common varieties are:
Nylon 6:
- Produced by polymerizing caprolactam, a cyclic amide.
- It is known for its durability, wear resistance, and elasticity.
- Used in textiles, automotive components, and industry.
Nylon 6,6:
- Constructed from hexamethylene diamine and adipic acid.
- This has more heat resistance and strength than Nylon 6 so it is ideal for mechanical and structural parts such as gears and bearings.
- There are various types of Nylon 12/11 and 4 variants, apart from these popular ones, which are all designed for certain applications, according to their chemical resistance, pliability and thermal conductivity.
- Key Properties
Nylon is unique in these aspects, which makes it a great material for many uses:
Durability and Strength:
Nylon has superior tensile strength, thus it resists wear and tear. Such toughness makes it suitable for clothing and carpets, as well as industrial items such as ropes and vehicles.
Lightweight:
Nylon, though extremely durable, is also lightweight and is therefore a good material for products where strength and weight are key factors (such as for athletic clothing or automotive parts).
Heat, Chemical and Wear Resistance:
Nylon’s ability to withstand abrasion, chemicals and extreme temperatures make it popular in a wide range of sectors. That hardiness enables it to stay put in shape and function for an extended time and, unfortunately, also allows it to survive in the environment.
Non-Biodegradable:
Nylon’s polymerity makes it resistant to decomposition in the environment. While natural materials such as cotton and wool naturally decompose fairly rapidly, nylon languishes in the environment for a far longer time, causing long-term devastation in landfills and ecosystems.
III. Understanding Biodegradability
Definition
A substance that is biodegradable means that it decomposes on its own by the processes of bacteria, fungi, or algae. The microbes consume complex materials, breaking them down into simpler elements (water, carbon dioxide, other organic compounds) and transforming the matter back to basic elements. It happens in soil, water and compost, where microbes can thrive under ideal conditions.
In order to be biodegradable, a material must have the ability to engage in this organic process without contaminating the environment. Biodegradable materials break down relatively quickly and are typically broken down within weeks to months, depending on the temperature, moisture content and the material itself.
Conditions for Biodegradation
Although all materials do not biodegrade in the same way, several things affect the process of biodegradation:
Temperature:
At higher temperatures, microbes tend to work faster. Biodegradation occurs more quickly in warmer, humid environments, and more slowly in colder environments.
Oxygen Availability:
Many organisms that digest organic substances need oxygen (aerobic organisms), but some (anaerobic organisms) do not. The oxygen content therefore influences the rate and timing of biodegradation.
Microbial Activity:
Environments require sufficient numbers and activity of microbes for biodegradation. Microbe-rich sites – compost piles for example – tend to degrade much more quickly than sterile sites, such as landfills.
Material Composition:
The way a material is molecularly structured makes a big difference in how readily it breaks down. Materials with highly complex synthetic polymers such as nylon do not biodegrade because their molecules are hardened for resiliency.
Biodegradable vs. Non-Biodegradable Materials
Biodegradable products are primarily natural materials – that is, plant-based products (paper, wood, cotton) – and they break down pretty rapidly under the right conditions. They oxidise into simpler compounds that are non-toxic and can be reabsorbed back into ecosystems.
Non-biodegradable substances, such as nylon, plastics and metals, do not easily decay in the wild. They are left alone for months or years, collecting in dumps, seas and habitats. Non-biodegradable substances are often very dangerous for wildlife and ecosystems because they can remain in the environment and may be chemically leached.
Some materials, such as certain bioplastics or artificial fibres, are marked as biodegradable but only when treated with specialised industrial composting procedures. Such conditions are not present in the natural world, so they are misunderstood as biodegradable.
IV. Is Nylon Biodegradable?
Here’s the reality: Nylon Is Not Inherently Biodegradable.
An artificial polymer made from petrochemicals, nylon is one of the most widely used materials in the world, both in textiles, industry and clothing. This material is tough, robust, and flexible, which is a great option for goods that require protection from wear and tear. But in the eyes of the world, nylon’s durability is a challenge.
One of the most pressing environmental issues about nylon is that it isn’t biodegradable. This means that, in nature, nylon does not decay and recompose into more organic compounds, as some natural substances, such as wood or cotton, do. This inability to be biodegradable is devastating to our environment because nylon waste products can persist for decades or centuries.
There are many reasons why nylon resists biodegradation:
Synthetic Nature:
Nylon is a synthetic polymer, which simply means it’s made artificially with chemicals. These reactions create stretches of long molecular chains that are inherently resistant to microbial degradation. While living things such as bacteria and fungi commonly break down organic material by eating and digesting it, synthetic polymers such as nylon have a complex molecular structure that no organism can effectively break down.
Molecular Structure:
Because nylon has a durable molecular structure. It is designed to be tough, flexible, and impervious to temperature, scratches and chemicals. These attributes lend nylon its favourable appeal in products that require long-term durability, but they also entail that nylon is not necessarily as easily biodegradable as other materials. The chemical bonds in nylon are, in effect, sturdier than ever, making them difficult for microbes to breakdown.
Lack of Microbial Activity:
Nylon resists the kind of microbial activity that results in its breakdown in nature. Material needs to be exposed to certain conditions in order to break down biologically, such as temperature, moisture, and microorganisms that can digest the polymer. In the vast majority of natural ecosystems, these conditions are not present in sufficient amounts for nylon to spontaneously degrade.
Degradation Time
The length of time it takes nylon to degrade in the environment will vary depending on environmental conditions, temperature, and the presence of microbes. Yet most people know that nylon textiles will take decades or centuries to degrade. This may vary depending on the environment, but it is certain that nylon doesn’t decay in a reasonable period of time when compared with natural fibres such as cotton or wool, which decay in a matter of months or years.
Nylon products can sit in landfills intact for decades because they lack oxygen and are less microbially active than they would otherwise be. Even in more dynamic environments, like forests or oceans, nylon materials aren’t fast-wearing. For instance, decommissioned nylon fishing nets — also known as “ghost nets” — can sit in the ocean for decades and continue to disrupt marine ecosystems.
Environmental Implications
The non-biodegradability of nylon has several environmental implications, resulting in waste issues worldwide and contamination of land and sea. The nylon waste is the major problem because it does not decompose naturally and remains at the surface and in the ocean for decades.
Accumulation in Landfills:
When nylon textiles — clothing, carpets, and the like — are discarded, they are usually deposited in landfills. Because nylon doesn’t biodegrade, these materials fill up a large landfill space, adding to the increasingly massive waste problem. Because nylon is able to remain in landfills for so long, non-degradable waste takes up valuable space, and inevitably eats up space that biodegradable waste needs. This leads to stressed waste networks.
Contribution to Ocean Plastic Pollution:
Ocean plastic pollution is perhaps the most blatant environmental consequence of nylon. Nylon is a widely used material in fishing nets, and abandoned or missing fishing nets (“ghost nets”) are a major source of marine pollution. Such nets can remain in the sea for decades, trapping marine animals, rupturing ecosystems and fuelling ocean plastic pollution. It is a form of pollution that can be catastrophic for the marine environment, leading to ingesting plastic particles and being entrapped, injuring or killing organisms.
Microplastics:
As nylon clothing or carpets degrade over time, they do not completely decompose into organic matter. Rather, they splinter into ever-smaller particles, contributing to the ubiquitous microplastics problem. Microplastics are tiny plastic pellets – generally less than 5 millimetres in diameter – that can find their way into the ecosystem, and ultimately into the food chain. These particles are often too small to be removed by filtration systems in sewerage treatment plants, and they accumulate in rivers, oceans and soil. When eaten by sea creatures, microplastics can be dangerous, both to the animals and to humans who eat seafood.
V. Myths About Nylon Biodegradability
Though scientists have said that nylon cannot be biodegraded, myths have sprung up about its ecological footprint. These myths are rooted in misrepresentations or greenwashing, in which corporations exaggerate the environmental advantages of their products.
Myth 1: “Nylon rots after a few years.”
Fact:
The truth is that nylon might degrade under certain controlled conditions (heat, pressure, exposure to chemicals), but not in the wild. Nylon is slow to degrade in ordinary environments, such as soil, ocean or landfill. The conditions required for nylon to break down quickly, including those of a lab or industrial composting site (temperatures, humidity and microbiological activity), must be replicated, and are seldom found in nature.
Nor would the degradation of nylon under high temperatures or pressure render the material essentially unusable on the planet. The degrading of nylon can generate toxins or microplastics that damage the environment.
Myth 2: “Biodegradable nylon works.
Fact:
A search for biodegradable alternatives to conventional nylon has been ongoing, and several candidates have emerged over the past few years. But it remains misguided to assume that biodegradable nylon is easy and a viable option. Several biodegradable polymers derived from renewable sources (vegan fibres, for example) are under development, but these remain short- and inconvenient.
It’s still not commercially available to make biodegradable nylon, and it’s possible that the materials on the market don’t decompose quite as quickly as they are advertised. For instance, some biodegradable nylons would break down only under industrial composting conditions, not in oceans or landfills. Even so, there remain problems with the properties of these materials – their reliability, expense and sustainability.
To date, biodegradable nylon is not the answer to the growing problem of plastic pollution, and conventional nylon is a non-biodegradable material that can linger in the environment for years.
Myth 3: “Nylon will eventually break down in nature.”
Fact:
People often make the mistaken assumption that nylon eventually decomposes in the environment, even if it takes a long time. However, this is not true. The habitats that allow nylon to decompose are rarely found in nature.
It requires oxygen, heat and microbial activity for nylon to break down. These conditions do not occur in landfills or the sea, where nylon waste is most frequently dumped. For instance, in landfills, the absence of oxygen and microbial growth prevents nylon from decomposing; in the oceans, nylon materials remain floating for decades, with no degradation. In the wild, there’s just no environment that is conducive to decomposing nylon as meaningfully as it could be.
Therefore, nylon’s inability to be biodegradable is not a short-term problem that can be cured by time, but a long-term environmental challenge.
VI. Environmental Impact of Nylon’s Longevity
Because nylon isn’t biodegradable, the chemical can remain in the environment for decades at a time, and have long-term environmental effects. These impacts range from overpopulation of landfills to marine pollution and microplastic emissions.
Landfill Overload
As one of the most widely-used materials in the world, nylon is frequently deposited in landfills. Because nylon doesn’t naturally decompose, it builds up and accumulates over time, leading to the global waste problem. When nylon textiles, especially synthetic textiles such as clothes, carpets and upholstery, are thrown away, they tend to end up in landfills. Because nylon is incredibly strong, although it takes up so much space in the garbage cans, it won’t decompose in a timeframe that makes sense. This burden of nylon trash adds to our growing waste problem and takes up space that would otherwise be available for biodegradable garbage.
Marine Pollution
One of the most pernicious environmental consequences of nylon’s resiliency is marine pollution (particularly ghost nets). Lost or lost at sea, nylon fishing nets have been a major source of pollution in the ocean. Such nets can sit in the ocean for decades, engulfing sea creatures and inflicting unprecedented damage on environments. Because nylon is toxic, and it can be quite tough, it’s particularly lethal to marine animals that get caught in these nets. Once trapped, aquatic creatures will be unable to swim away without injury or death.
Nylon also occurs frequently in other ocean waste, including plastic bags, ropes and packages that remain in the sea, part of the plastic pollution problem at large.
Microplastics
With each nylon item worn, it degrades into smaller and smaller pieces – thus increasing the microplastic problem. Such microscopic plastic pellets, less than 5 millimetres across, can virtually never be emptied out of the environment. Microplastics, once released into the ocean or another environment, can be consumed by marine life, deposited into the food chain and even enter human populations. Microplastics that accumulate in ocean environments sever food chains, erode biodiversity and even destroy ecosystems in the long term.
Because nylon isn’t biodegradable, it sits in the natural environment, slowly breaking into smaller pieces, becoming part of the world’s microplastics problem, which impacts animals and people everywhere.
VII. Alternatives to Nylon and Potential Solutions
Since the environmental harm caused by nylon’s continued existence in ecosystems increases, finding replacements for the hard-to-degrade non-biodegradable material has become a priority. There are several approaches that might mitigate the harm caused by nylon on Earth, from better recycling practices to bio-based polymers with more sustainable and biodegradable qualities. This section is about alternatives to nylon, including recycling processes, biodegradable polymers, and consumer options.
Recycling Nylon
Recycling is one of the most promising alternatives to confronting the waste of nylon in the environment. Even though nylon is difficult to biodegrade, recycling can be used to recycle the material and avoid it entering landfills and oceans. There are two primary approaches to nylon recycling: mechanical and chemical.
Chemical Recycling
Chemical recycling involves reducing nylon to its basic chemical elements which are then recycled to make new nylon. In contrast to mechanical recycling, where the material is smashed into a single piece, chemical recycling allows nylon to be stripped down to its monomer form. This method can handle mixed or contaminated nylon wastes, which pose an issue for mechanical recycling.
A leading chemical recycler in nylon is Econyl, which makes its own recycled nylon from industrial waste. Econyl is produced by chemically decomposing used nylon, from fabric scraps, carpets and fishing nets, into their smallest monomers. This cleans these materials and recombines them into premium nylon fibers, suitable for a variety of uses, from clothing to industrial textiles. By recycling waste, we save virgin nylon, thereby saving carbon emissions and the use of petroleum resources.
The greatest advantage of chemical recycling is that it takes care of a variety of nylon materials that otherwise would be discarded, restoring value to products that would otherwise pollute the environment. The downside, though, is that the process is energy-consuming, and certain chemicals used in the recycling process might have adverse environmental impacts.
Mechanical Recycling
The more popular nylon recycling is mechanical recycling. This process is used to melt and reprocess nylon products, such as old clothes or carpets, into new products. It doesn’t dissect the substance into its chemical constituents but instead mechanically restructures the nylon. Mechanical recycling is typically less costly and more energy-efficient than chemical recycling but is still subject to drawbacks.
The most fundamental drawback of mechanical recycling is that it requires very clean inputs. Recycling will be less efficient if the nylon is combined with other stuff, like elastane or polyester, or soiled with dirt and oil. In addition, mechanical recycling will degrade nylon over time, since repeated recycling weakens the fibers. This means that mechanically recycled nylon products may be relatively short-lived, which limits the material’s potential for heavy-duty applications.
Mechanical and chemical recycling are good choices but aren’t perfect solutions in their own right. To make nylon recycling more effective and widespread, we’d need better systems for receiving and sorting nylon waste. Further, newer recycling technologies might minimise the ecological cost of chemical recycling and make mechanical recycling more efficient.
Biodegradable Polymers
Yet another replacement for traditional nylon is the synthesis of biodegradable polymers that gradually decay into natural materials. These are made from renewable sources and are sometimes marketed as being greener because they do not end up in landfills or oceans like synthetics like nylon.
Polylactic Acid (PLA)
Perhaps the most famous biodegradable substitute for nylon is polylactic acid (PLA). PLA comes from renewable plants, like corn or sugarcane, and can be composted in some circumstances. It finds many applications across a wide spectrum, including food packaging, textiles, and medical instruments. PLA has a big edge over nylon in that it can decompose in industrial composting conditions or in microbial-friendly environments. PLA breaks down within months or years — in contrast to nylon, which decays over the decades and is dependent on the environment.
PLA, for all its virtues, does not perform perfectly well as an alternative to nylon in high-end applications. PLA is not as strong and pliable as nylon, and might not hold up as well under stress. PLA, for instance, is not as resistant to heat and moisture as nylon, which makes it a poor material for outdoor clothing or heavy industrial applications. Further, PLA still needs specific conditions to degrade, and when it lands in landfills or oceans it might not decay as quickly as is intended, causing some of the same environmental problems as old plastics.
Challenges to Replace Nylon for Heavy-Duty Uses
Though biodegradable materials such as PLA have a bright future for sustainable materials, they’re not quite ready to completely replace nylon for heavy-duty use. Because nylon is strong, wear-resistant, pliable, and chemical resistant, its use ranges from textiles to automotive components to industrial machines.
Biodegradable alternatives, like PLA, just don’t have the same combination of performance and resistance in extreme situations. Until new biodegradable polymers can duplicate the physical characteristics of nylon, biodegradables are unlikely to completely replace nylon in applications where toughness and durability are critical. But scientists are developing technologies that could enable biodegradables to perform better and gain greater reach into sectors where nylon prevails.
Consumer Choices
Nylon consumers, too, have their own role to play in making nylon less destructive to the environment. Perhaps the most efficient approach for consumers to make a difference is to use recycled nylon. Consumers who shop for products using regenerated nylon are helping the recycling industry and easing the need for virgin nylon. Econyl products, for instance, which are produced from waste material such as discarded fishing nets and textile scraps, offer a more sustainable alternative to nylon.
Aside from purchasing recycled nylon products, users can decrease their reliance on single-use or disposable nylon products. Many everyday nylon products – shopping bags, packaging, clothing – are merely used for a short period and then tossed away. By opting for reusable alternatives (fabric bags, organic clothing, rugged hiking equipment) we can help to cut the demand for new nylon production. The encouragement of brands to use sustainable production techniques and purchase recycled fabrics also contributes to increasing the use of greener fabrics.
Third, joining take-back schemes or donating obsolete nylon goods to be recycled will help keep nylon out of landfills and promote the development of a more sustainable recycling system.
VIII. Future Research and Innovations
Though today’s nylon substitutes are a good start, much more remains to be done to make sure that the materials being substituted for nylon are truly sustainable, biodegradable, and useful in a variety of uses. Ultimately, advances in recycling technology, bio-nylon and circular economies could result in more sustainable solutions for nylon waste.
Enzymatic Recycling
One exciting field of work involves the creation of enzymatic recycling for nylon. Enzymatic recycling uses enzymes to dissolve nylon into chemical bonds. The advantage of enzymatic recycling is that it may offer a more energy-efficient and greener way to recycle nylon than the old-fashioned chemical process. Some enzymes have been discovered to breakdown synthetic polymers such as nylon into simpler monomers. If this process can be streamlined, more effective recycling networks can be built that minimise the environmental impact of nylon manufacture.
They’re still trying to optimise the enzymatic recycling process and develop enzymes that break down a broader range of nylon compounds. The technology is still in its infancy, but could be extremely useful in minimizing the carbon footprint of nylon and making it more recyclable.
Bio-Nylon
Another area of investigation is the production of bio-based nylon, produced from renewable resources such as plant sugars or oils. Bio-based nylon does not require raw materials sourced from fossil fuels, while conventional nylon requires materials that can be recycled. Some bio-based nylons are constructed to be more biodegradable than traditional nylon so that they are less impactful on the environment. Bio-Nylon is in its early days and still requires much research to scale up production and boost its capabilities in high-end markets.
The big problem with bio-based nylons is that they cannot achieve the same performance, quality and affordability as conventional nylon and also be biodegradable. In industries where demand for greener materials is high, bio-nylon should prove to be an economically more sustainable alternative.
Circular Economy Models
Developing circular economy products, aiming to reuse, recycle and create the least amount of waste, is one area where the pursuit of sustainable solutions has turned into a key theme. Models of the circular economy encourage recycling of materials such as nylon so that they are continually regenerated. In order to do this, manufacturers will have to design items to be easily recyclable, manufactured from materials that can be effectively decomposed and reused.
Nylon products can be made more recyclable by reducing material composition complexity, mixing fewer components and having them durable enough to withstand multiple cycles of recycling. It would be much more environmentally sustainable to create a closed loop for nylon so that it can be reused again and again. Such a strategy would also require manufacturers, consumers and governments to coordinate efforts to increase recycling infrastructure, reduce waste, and use sustainable materials.
Dhanya Nair is a fabric Lover and a mom. She offers a unique perspective on the intricacies and history of fabric and specializes in bringing the unique narratives of textiles to life.