Unlike common plastics derived from petroleum-based sources, bioplastics are derived from renewable biomass products such as vegetable oils or agricultural waste. Popular bioplastics, such as those based on polylactic acid (PLA) polymers, are also biodegradable, reducing their impact on the environment.
A recent study from Research Report Insights highlighted that global sales of bioplastics for packaging are projected to increase at a CAGR of 13.8% from 2017 to 2027. However, a key focus moving forward will be reducing the cost of bioplastic production, as well as ensuring it is as sustainable as possible.
“The chemistry is there,” says Dr Ashlee Jahnke, head of research at UK-based start-up Teysha Technologies. “The real trick that held these types of technology back is their cost and ways to manufacture them in an eco-friendly way.”
Recently, Teysha unveiled a ground-breaking new natural polycarbonate platform which, according to Jahnke, stems from years of laboratory research at Texas A&M University. The company’s technology is able to create fully biodegradable substitutes for existing petroleum-based plastics using natural products.
The result is AggiePol, Teysha’s flagship bioplastic, which is derived from sustainable feedstocks and can be physically, mechanically and chemically tuned to suit the needs of its intended application. But what are the implications of such a platform for the packaging industry?
Joe Baker: Can you explain more about what this new platform is?
Dr Ashlee Jahnke: PLA, purified terephthalic acid or some of the popular [bioplastics] have a very specific polymer structure. They can be changed via additives and the way things are processed to get different properties.
Rather than a single polymer, what we have is a platform where we can take various natural products and convert them into the building blocks that we need, and so that gives us a plug-and-play system. Depending on the target properties of the materials that we want to make, we can use different components to build into the polymer and tune things such as mechanical and thermal properties.
JB: What distinguishes this platform from other bioplastic innovations?
AJ: I’d say there’s two main distinguishing features of this platform – one being that we can tune it to various applications and properties based on the end user’s needs. We really have been focused from the beginning on the entire polymer lifecycle; we’re not just interested in sustainably sourcing the materials to make the polymers, but what happens to the polymers at the end of their useful lifetime.
For example, if they end up in our waterways they can still persist for hundreds of years and cause some of the same issues that petroleum-based plastics do. We have developed our system to be hydrolytically degradable so, after the end of its useful lifetime, if it does make its way to rivers, lakes, or oceans it can break down fairly quickly.
Depending on the co-monomers that we use or specific additives, we can speed that process up or slow it down – it’s based on moisture content, so the water coming in and breaking the bonds in the polymers. We don’t want everything to degrade in ten years. You may want to use a plastic product longer. And so there’s ways that we can work to tune that degradability.
There’s no one answer; it really depends on the application and where it’s most likely to end up after the end of its usual lifetime.
JB: How does this platform create a reduced environmental impact compared to the production of normal plastics?
AJ: First and foremost, the key to any bioplastic is sourcing feedstocks from renewable plant-based sources rather than petrochemical sources, which are typical for a lot of the polymers out there.
Step one for us is finding ways to use a renewable source, but as we thought about that we also wanted to be careful not to divert food crops because, for example, we’re using good land to grow corn to derive our feedstocks. While that might be a step in the right direction, it’s still problematic in many ways, so we’ve really turned our focus to agricultural waste products. Things that are being thrown out anyway, but that have particularly high starch content is what we’re focused on right now.
We’re really just working on adapting our chemistry to [convert] waste starch into our monomer building blocks in not only as few steps as possible, but as cleanly as possible, so minimising the energy usage that goes into those synthetic steps and recycling reagents where possible to minimise waste. So we’ve built in some recycling loops in our process as well as using CO2 capture to generate some of the reagents that we use along the way.
JB: What implications could this have for the packaging industry?
AJ: Packaging is one of the very large sources of single-use plastics that are out there. It’s important – we need to seal and package and move things but we need to work towards doing that as sustainably as possible. There’s definitely been a lot of progress in using recycled polymers in packaging, but there’s also a lot of challenges in the recycling process and keeping the properties that you need – mechanically, thermally and aesthetically.
There’s a wide range of packaging types and what we’re sticking our heads out first on is some different options for cosmetics – jars, tubes, things like that. Because of the way the system works, we can move into film packaging or more rigid plastic packaging. It really will be one of those things we’ll explore as we get those first generations out on the market.
JB: Have you seen a major increase in demand for bioplastics in the packaging industry?
AJ: We’re seeing that right now. A lot of the demand is brand-driven, so brands that are already taking an eco-friendly stance are more eager to move their packaging over in that direction. As regulatory pressure and consumer awareness continues to grow, the number of brands that are doing that does seem to be increasing.
JB: A lot of people say that bioplastic is still plastic, and that solving the environmental issue will be more about human behaviour and recycling than providing alternatives – why is pursuing a platform like this still viable?
AJ: It’s a fair question. We are not against reduce, reuse, recycle – those are great goals that we’ve been making a lot of progress towards them as a society. But changing human behaviour is very difficult and it’s somewhat of a slow going process.
Recycling is getting better and that’s a positive thing but it’s still often an energy-intensive process in and of itself. So it’s another piece of the puzzle that we can add as we continue to make progress. To reduce our dependence on plastics, specifically single-use plastic, is still a positive direction. But right now there’s just still some things we need plastic for and so we really just want to step in and make those systems sustainable.
JB: Now you have this platform, what are your next steps?
AJ: Our first-generation material has shown us a proof of principle that we can get this wide range of properties and degrade on different timescales. Our focus right now has really been on research and development, so going back through and reworking that chemistry to prove the platform and really doing it in a way that worked so that we could make the materials and make sure that they were worth pursuing further.
So now we’ve been going through and developing so that when we do scale up our chemistry is as green as possible. We’ve had good success with that, so now we are working with a couple of partners that will start making some packaging! [We are doing] smaller orders initially to start getting the materials out there in the consumers hands and see how that goes.