Fossil fuels have been around for hundreds of millions of years, but consumption has increased rapidly in the last couple of centuries or so. Reserves have depleted, new ones are harder to find and they certainly won’t last forever. It goes without saying that our continued reliance on fossil fuels has seriously impacted the environment.
Aside from the carbon emissions that are caused by burning fossil fuels, there are also the environmental consequences and costs of transport, such as CO2 emissions, oil spills and flammable natural gas leaks.
Renewably-sourced plastics, however, have been slow to catch on. Bioplastics still represent only about one per cent of the more than 359 million tonnes of plastic produced each year. There are several reasons for this.
Firstly, bioplastics are costly compared with traditional plastics. Polylactic acid (PLA) plastics can be 20 to 50 per cent more expensive because of the relatively complex process of deriving the building blocks for PLA from corn or sugarcane.
Recent data from the European Bioplastics Association also found that overall growth of the global bioplastics industry is currently being slowed by the low oil prices and “a lack of political support for the bio-based economy.”
Also, while manufacturing bioplastics may not result in the same fossil fuel emissions as petrochemical plastics, the use of fertiliser and pesticides and deforestation in order to produce corn and sugar can counter the benefits.
Misinformation about bioplastics also remains prevalent. Confusion reigns about what exactly a bioplastics is. Are bioplastics the same as biodegradable plastics? And if a plastic is biodegradable, what are the conditions needed for this to happen? Why don’t industrial compostable materials compost at home?
The UK government has compiled a report entitled Standards for Bio-based, Biodegradable and Compostable Plastics in which it has attempted to answer these and other questions.
Nevertheless, demand for bioplastics is rising despite the hurdles. The onus to satisfy this growth will fall to plastic producers that can find new and innovative ways of producing them, with more sophisticated biopolymers.
Among these innovators is Teysha Technologies, which has achieved a landmark breakthrough in creating a viable substitute for existing petroleum-based polycarbonates. This research was motivated by a desire to counter negative impacts that occur when polymer materials persist beyond their useful lifetime.
Teysha’s building blocks are sourced from natural feedstocks such as starch-rich agricultural waste. These feedstocks are broken down carbohydrate compounds, which are used to design bioplastics with targeted physical, mechanical, and chemical properties for various applications.
Teysha’s bioplastics degrade under a variety of conditions, with the rate of the degradation being dependent on the specific chemical makeup of individual materials.
These natural building blocks have a higher chemical diversity than typical hydrocarbon sources such as petroleum — therefore, it’s possible to expand and tune the chemistry and degradation rates. Hydrolytically degradable linkages allow for degradation in any environment containing sufficient moisture, and the natural product building blocks allow for microbial breakdown in biodegradation scenarios.
Teysha’s polymers are not a “dead end”. Rather, they are built in such a way that their deconstruction can avoid both plastic persistence and pollution, and provide future chemical recycling for the next generation. Essentially, this creates multiple lifetimes for a single starting natural resource.
There are still obstacles to solving the plastics problem. But, at the very least, new innovations in bioplastics that continue to emerge should help loosen the reins on this emerging sector.
Ashlee Jahnke is the research director at UK-based Teysha Technologies.