• Brooke Roberts-Islam

Creating synthetic materials that don't shed microplastics: In Conversation with Polymateria

Polymateria scientists at Imperial College London. Image: Polymateria

Last week, the RSA issued a report claiming that “half of ‘fast fashion’ is entirely made from new plastics”. The “Fast Fashion’s Plastic Problem” report from the Royal Society for Arts, Manufactures and Commerce (RSA), analyses 10,000 recently-listed items from some of the biggest online brands in ‘fast’ fashion: Asos, Boohoo, MissGuided and PrettyLittleThing. The research shows that the vast majority of items, which were balanced across multiple product categories, contain new plastics, with half being entirely made from petrochemical-derived polymers including polyester, acrylic, elastane and nylon.

Whilst this is an issue in terms of finite petrochemical resource use, it is also an environmental issue due to microplastic waste generated during production, washing and wearing of the clothing. Microplastic shedding from plastics, including textiles and clothing, has resulted in the omnipresence of plastic in our food, water and soil. Due to our ‘throwaway culture, the RSA warns in the report that the bulk of garments, such as those analysed, are ending up in landfill, contributing to the rapidly escalating microplastic problem.

The consumer element of purchasing plastic clothing requires education and transparency, however, the redesign of materials is key to ensuring an absence of toxic additives and compatibility with returning to nature - as all materials inevitably do. To explore this concept further, and examine the landscape of synthetic polymer innovation that seeks to tackle microplastic pollution, I spoke to Niall Dunne, CEO, Polymateria and Sustainability Advisor Board Member, UK Research and Innovation.

Polymateria has developed plastic packaging with time-sensitive biodegradability, balancing the performance of the plastic with the inevitable return to nature within a given timeframe (between 6 months and 3 years.) Dunne is set to join the Techstyler + Conservation X Labs Microfiber Innovation Challenge panel discussion on June 22nd to debate the microplastic problem and solutions, but in the meantime, here is a primer to set the scene.

biodegradable plastic cup
Polymateria's Cycle+ fully biodegradable plastic cup. Image: Polymateria

“Crystallisation is the biggest challenge” in tackling biodegradation of plastic, says Dunne. “Taking (the plastic) back to a grease or a wax-like state” is required to eliminate microplastic shedding. “A big reason why a lot of innovation in this space has failed is they've not figured out how to do that,” says Dunne.

Polymateria have solved this problem by stabilising their plastic packaging using a “barrier layer” which offers “protection characteristics for a period of time, so (there is) a time-controlled aspect of the technology to allow for the types of performance requirements.” Once that time is up, Dunne explains that the packaging can return to the natural environment. But once the barrier layer ‘expires’, how does the plastic biodegrade without shedding microplastics?

The category of plastics Polymateria works with are called polyolefins. These are plastics made from hydrocarbons (from crude oil) that can have a range of characteristics, depending on how they are formed using different chemical catalysts. Polyolefins can be liquid-like or rigid solids, depending on two key factors: molecular weight and degree of crystallinity. Polyolefin degrees of crystallinity range from 0% (liquidlike) to 60% or higher (rigid plastics). What’s critical about biodegradation is the crystallinity of the final plastic. Polymateria's plastic has minimal crystallinity, whilst simultaneously performing a stable packaging for a specified timeframe, after which biodegradation will begin. These factors combine to form Polymateria’s biodegradable plastic packaging solution, defined as biotransformation. I am curious to know whether biotransformation could be applied to synthetic textiles that are used in 'fast' fashion, given that such products are often treated as disposable and are worn just a handful of times before ending up in landfill. Dunne thinks this might be possible.

The challenge, it seems, is balancing the performance characteristics demanded of synthetic fibres, yarns and textiles, with the molecular weight, and therefore the crystallinity. A commonly used polyester for textiles and apparel is polyethylene terephthalate (PET), due to its durability, its resistance to chemicals, shrinking, wrinkling and abrasion, and also its hydrophobic nature, making it quick-drying. PET, however, has a typical molecular weight of around 8,000 – 31,000, which places it firmly in the non-biodegradable realm (see the table below), leaving behind harmful microplastics.

Biotransformation. Image: Polymateria

Could bio-based plastics be the answer? What are the benefits, trade-offs and limitations? Dunne is cautious about this field because whilst it tackles feedstock, the microplastic shedding problem remains. The input material may be canola oil or renewable plant matter, for example, but the stability and biodegradability of the final plastic depends on the chemical characteristics of the resulting plastic.

Digging deeper into biodegradation, Dunne shares concerns about the reliability of landfill biodegradation. “I'm struggling to think of any (landfills) in the world that are managed to anaerobic conditions at 60 degrees, 24 hours a day, seven days a week - there isn't a landfill in the world that's managed that way.” “They may bulldoze and turn (the waste) over, but that's not anaerobic.”

He describes landfill objects as being “mummified” and cites the documentary “The Secret Life of Landfill” where items landfilled decades ago are unearthed, including fully readable newspapers and wearable clothes. The lack of clarity over how landfills are managed (we scratched the surface of this during the recent Techstyler + Conservation X Labs Fireside Chat with Billi London) is a cause for confusion and concern. Consumers, and businesses, rely on obtaining accurate information from municipal authorities on landfill maintenance, which in practice may be difficult to obtain.

landfill being bulldozed
Landfill management. Stock Image.

With the lack of universal landfill management and the reality that bio-based feedstocks are not a solution to microplastic shedding, the textile and apparel industry faces a challenge with multiple potential paths to eliminating microplastics. Upstream, there is a material science challenge in ‘redesigning’ synthetics to perform adequately as textiles, but simultaneously, as low-crystalline ‘liquid like’ materials that will biodegrade safely in nature. Polymateria have time-controlled this with a coating, but how could fibres, yarns and textiles for apparel replicate this? Other avenues include architecturally 'augmenting' the textiles to chemically or mechanically reduce/eliminate microplastic shedding.

Further downstream, microplastic fibres are already being captured by water filtration, but this does not capture all microplastics, or prevent their eventual return to nature. A final (perhaps obvious) option is to replace synthetic fibres with 'natural' ones that do not contain plastics. To support and ignite innovation in replacing harmful synthetic fibres or ‘augment’ them to reduce or eliminate microplastic shedding, the Microfiber Innovation Challenge is offering a share of $650k to fund research and innovation in these areas and is open for entries until 25th June, 2021.

Ahead of the application deadline, join us on 22nd June at 3 pm BST to discuss tackling the microplastic problem from a material science, consumer brand and innovation perspective with Niall Dunne, CEO of Polymateria, Kyle Blakely, Vice President, Materials and Manufacturing Innovation at Under Armour and Barbara Martinez, Open Innovation Director at Conservation X Labs, who will be on hand to answer questions related to the Microfiber Innovation Challenge.

As this goes to 'print', Polymateria have been Awarded as Technology Pioneers by the World Economic Forum, recognising the 100 most promising Technology Pioneers of 2021 that are shaping industries. Polymateria were awarded in the category of circular design and prevention of plastic pollution. More information about how the award will impact Polymateria's biotransformation work will be presented in the panel discussion on 22nd June.

For more information on EU assessment on the bio-waste opportunities and challenges, click here and also check out: Towards a circular economy - waste management in the EU.

Sign up for the final virtual event in the Microfiber Innovation Series here.