How advances in alternative plastics could help address the waste crisis

Plastics, much like the hydrocarbon cousins they’re derived from, are inherently useful. Cheap, abundant, and multifunctional, they touch virtually every aspect of daily life, from clothing, packaging and consumer goods to electronics, automotive components and medical devices. 

But this utility has fuelled ubiquity and, in the absence of adequate circular practices, plastic waste has become a major environmental hazard. Around 450 million tonnes of plastic waste is generated globally each year, with less than 10 per cent recycled. The remainder is incinerated, sent to landfill or littered, with an estimated 2 million tonnes washing into our oceans.

At this stage the problem is well known but, just as with fossil fuels, behaviour has been resistant to change. In December 2024, representatives from nearly 200 countries came together for the INC-5 talks with the aim of establishing a global plastics treaty. However, just as with the COP talks to tackle emissions, major oil-producing countries blocked meaningful progress.

Dr Marc Rodriguez Garcia, Xampla

In the absence of a global agreement, the best hope for tackling the plastics crisis may lie with technology - tweaking plastics to make them biodegradable or replacing petrochemical feedstocks with plant material. And with a global plastics market north of $700 billion - set to top $1 trillion by 2033 – the incentive is financial as much as it’s environmental.

One of the biggest challenges is single-use plastics, pervasive across everything from packaging and FMCG (fast moving consumer goods) to takeaway boxes and coffee cups. While many single-use items – plastic straws for example - can be easily identified and replaced with greener alternatives, others are less visible and have functionality that biomaterials struggle to match.   

“I think one of the main challenges with new materials like bioplastics in general, is that they do not easily integrate with existing recycling streams,” Dr Marc Rodriguez Garcia, co-founder and CTO at Xampla, told The Engineer.

Spun out of Cambridge University, Xampla converts protein feedstocks from plants such as peas, potatoes and rapeseed into sustainable biopolymer materials. Initially aiming to replace a range of single-use plastics, more recently the company has narrowed its focus.

“Most of our progress has actually been on focusing on certain applications where, essentially, our materials can replace the types of plastics which are impossible to recycle,” said Rodriguez Garcia.

A primary target for Xampla are the thin plastic coatings applied to cardboard and paper that act as a barrier against grease or liquids. These super thin layers of polymers – sometimes containing PFAS or ‘forever chemicals’ – are prevalent in coffee cups and takeaway boxes. The coatings can be particularly pernicious as consumers often believe the packaging is recyclable, when in fact the plastic layers contaminate recycling streams.

“Coatings on paper, for example, these are the types of very thin layers of plastics that are too small to be captured in existing recycling waste streams, and especially if they’re part of a separate material like a cardboard box,” said Rodriguez Garcia.

“The paper potentially can be recycled, but a very thin plastic layer, which is only like a few microns thick…that’s very thin to actually be captured in the recycling stream…the highest likelihood for them is to end up being incinerated or actually leaking into the environment. So all of our applications are specifically focused on trying to replace those invisible plastics and I think that’s now become our USP.”

Xampla’s Morro coating provides similar functionality to these existing plastic coatings but allows the underlying paper or cardboard to be recycled. A deal last year with Finnish consumer packaging company Huhtamäki and the 2M Group of Companies will see takeaway boxes featuring Morro rolled out commercially. This follows a licensing agreement between Xampla and 2M for the latter to produce Morro at industrial scale.

“Manufacturing these materials at scale, it takes a lot of investment and it fundamentally takes a lot of expertise,” said Rodriguez Garcia. “That’s why we decided to go down the route of licensing and these partnerships with companies like 2M who have been manufacturing chemicals and other bio-based ingredients for decades.”

Another emerging use case for Xampla’s technology is microencapsulation – using the biopolymer to encase things like fragrance oils or vitamins in liquids. Often deployed in cosmetics or personal care products, microencapsulation protects ingredients and can extend shelf life but relies on harmful microplastics to do so. Xampla’s tech offers a biodegradable alternative.

“There’s like tens of thousands of tons of these intentionally added microplastics leaking directly into the environment,” said Rodriguez Garcia. “We can provide a completely natural polymer alternative to an existing plastic material that’s being used in that application.”

These single-use ‘invisible’ applications targeted by Xampla are relatively low hanging fruit where biopolymers could have a transformative effect. But it is not just the consumer segment that is driving change. The versatility of plastics means they play a role in almost every engineering sector, where durability is often paramount.

Floreon, another UK university spinout, specialises in high performance bioplastics. Based around research that originated at the University of Sheffield, the company takes plant-based biopolymer feedstocks and enhances them for a range of applications including toys and electronics.

“We take PLA (polylactic acid), which is a green polymer made from plants,” Dr Andrew Gill, Floreon’s technical director, told The Engineer.

“We make it possible to take it into durable applications, applications that are higher value and have a longer service life. We buy the PLA readymade from a supplier and our patent is about blending PLA in the right way with things that give it the properties of an engineering plastic.”

The PLA that Floreon relies on is largely derived from sugarcane and corn. This raises questions around the sustainability of bioplastics, with feedstocks potentially crowding out food supplies. But according to Gill, bioplastics have a negligible impact on land use.

“To make all the bioplastics in the world today, I think we require less than 1/25 of 1 per cent of global agricultural area,” he said. “So we’re not competing with food production.”

Floreon has developed three core PLA-based products. Bio-Tech is a food-safe, industrially compostable biopolymer and the greenest of the three. Stepping up from that is Dura-Tech, a tougher bioplastic with higher impact strength, which is recyclable but not compostable. Lastly comes Floreon’s latest development, Therma-Tech, a certified flame-retardant material to enable the use of bioplastics in a host of applications where they have previously been excluded.

“All of our grades have a lot of benefits in common,” said Gill. “They all have high renewable content. They have a low carbon footprint in production, and because of the low manufacturing temperatures, our customers can reduce their Scope Two emissions - the energy use in manufacturing - and their Scope Three emissions based on the carbon footprint of the materials in the products.”

Therma-Tech in particular has been garnering attention of late, helping Floreon scoop the Innovation Award at the Plastics Industry Association’s 2024 showpiece event. A first of its kind, the halogen-free flame-retardant biopolymer is opening doors for the company, taking bioplastics into applications that were previously off limits.  

Dr Andrew Gill - Floreon

“It’s a really standout innovation in that we’re not just competing with bioplastics, but we’re able to replace fire resistant engineering plastics such as flame-retardant ABS (acrylonitrile butadiene styrene),” said Gill. “Fire-retardant plastics - there’s a lot of concerns about the health and environmental impacts of the halogenated flame retardants that are being used today in those applications.”

Due to the potential for short circuits, plastics used in electronic devices must have a certain level of fire resistance. The specific classification Floreon’s customers were chasing was UL 94 V-0, an industry standard where a vertical sample of material is set alight from below, then must self-extinguish safely within 10 seconds with no flaming drips.

“When that stops, they put the flame back on again for a further 10 seconds and do the same,” Gill explained.  “Getting a plant-based material, a bioplastic, to pass that test and achieve the full V-0 rating was a real challenge.”

The added performance of Dura-Tech and Therma-Tech inevitably comes with some trade-offs on sustainability, with neither product being compostable. However, both have potential for chemical as well as mechanical recycling.

“Chemical recycling of PLA is becoming a real commercial reality now, so we don’t have to downcycle the material,” said Gill. “If you mechanically recycle any polymer, you’re probably going to compromise some of the properties. But with chemical recycling, we actually just filter out the flame retardant and we get the feedstock back so we can regenerate virgin polymer.”

But the biggest benefits originate upstream, with the footprint of Floreon’s products not deriving from fossil carbon. Downstream, this means that even if the material does end up incinerated, the CO2 released will have been recently captured as biomass, meaning its environmental impact will be much less than incinerated plastic made from hydrocarbons.

For the most part, incineration will be a last resort. Floreon’s durable plastics are designed for the long haul and should end up in appropriate recycling streams at end-of-life. As a result, biodegradability is less of a worry, sacrificed in favour of performance. 

For single-use biopolymers, biodegradability is essential. Disposed of in recycling, landfill or as litter, they need to be able to break down into harmless compounds over a reasonable timeframe, with no adverse impact on the environment.

Birmingham’s Aquapak has developed a material claimed to do exactly that. Known as Hydropol, the patented polymer is hydrophilic, dissolving harmlessly in water – a handy property for a class of material that frequently ends up in water systems by both accident and design. 

“It’s based on a raw material called polyvinyl alcohol (PVOH), which has been around a long time, but we formulate it in such a way that you can thermally process it,” Mark Lapping, Aquapak’s CEO, told The Engineer. 

“It’s already used in things like stitching and medical devices, dishwasher tablets, that type of thing, but no one made it so they could firmly process it for packaging or for consumer goods. That’s what our point of difference is.”

In a similar vein to Xampla, Aquapak’s target is the single-use plastic that can disrupt recycling streams at end-of-life. According to Lapping, Hydropol can be used to manufacture things like garment bags, crisp packets and sachets, items that too often end up as litter and washed into watercourses. Like Xampla’s Morro, Hydropol can also be used as a barrier coating for cardboard or paper. The material dissolves during recycling, leaving the fibrous pulp uncontaminated.

“Traditional plastics will stick to paper and don’t separate,” Lapping explained. “So it gives a real problem downstream for the paper recyclers, because they end up with this gooey mush with plastic and paper mixed together.

“Our material passes in solution, like sugar in your tea, into the effluent plant, where we’ll fully biodegrade, both aerobically and anaerobically.”

Unlike Xampla and Floreon’s products, Hydropol is currently derived from petrochemical sources, meaning it is not strictly a biopolymer. However, Aquapak is exploring bio-based PVOH feedstocks to further bolster the material’s green credentials.

Also in contrast to Xampla and Floreon, Aquapak keeps all manufacturing in-house, opting against the licensing route. Its 30,000 square foot factory can produce 10,000 tonnes of Hydropol pellets annually, using Aquapak’s patented formulation and process. Control over production is an important point of difference for the company, according to Lapping.

“That’s why we wanted our own factory to control that, because you have to control the reaction in the compounding to be able to make the product,” he said. “It’s been 10 years of R&D to be able to create something that is absolutely unique.”

Depending on the application, Aquapak can manufacture Hydropol with various degrees of solubility, designed to degrade in water of different temperatures.

“We can formulate everything between 25 degrees and 80 degrees (C),” said Lapping. “For instance, our product goes into making garment bags in Asia…that material is formulated to dissolve above 70 degrees centigrade, so it’s not going to break down in the presence of a bit of humidity in the atmosphere.”

Conversely, products unlikely to see exposure in high moisture environments could dissolve in water as low as 25°C, similar to the temperature found in most swimming pools. But even the products designed to withstand higher temperatures will break down in the presence of cooler waters, albeit over longer periods of time.

“You want to make sure the application you’re using it for in life fits the conditions that it’s going to be used in, but at the end of life, you want to know it’s going to break down safely,” said Lapping.

In 2024, Hydropol was used by The British Crisp Co. to create what’s claimed to be the world’s first fully recyclable crisp packet. Recycling non-profit OPRL certified the packs for kerbside collection streams, with consumers including it with their paper material.

With Brits getting through an astounding 8 billion packets of crisps each year – virtually all ending up in landfill or incineration - it’s a reminder of both the scale of the plastics problem and the capacity for new materials to make an impact. In the coming years, single-use polymers that don’t biodegrade may even become a thing of the past. That’s a lot of crisp packets, takeaway boxes and coffee cups that need replacing. And a huge opportunity for the companies engineering the solutions.