Tuneable bioplastic may revolutionise industry
29 January 2021
Plastics pose a problem for the planet. Whether it’s due to the fossil fuels used to produce them or the harmful chemicals released during their slow degradation process. Despite these issues, plastic has become so intertwined with our daily lives that giving it up presents a complex challenge. Here Dr Ashlee Jahnke, Head of Research and Development at bioplastic research specialist Teysha Technologies, suggests a sustainable solution to the plastic pollution problem.
In March 2019, the Ellen MacArthur Foundation published its New Plastics Economy report, which noted that eight million tonnes of plastic packaging is produced every year by 30 global brands. Almost 50 percent of this packaging was produced by Coca-Cola, totalling three million tonnes. In fact, Coca-Cola produces more plastic pollution than PepsiCo and Nestle combined, with all three being ranked the world’s top plastic polluters. This was corroborated in a study by Greenpeace in 2020, who found Coca-Cola packaging across 40 sites out of 42 surveyed on six continents. Much of this packaging will be single-use, so the majority of the eight million tonnes produced this year will be plastic pollution next year.
Breaking the chain
Unless they are recycled or incinerated, plastic products are either disposed of with general waste and destined to reside in landfill, or are thrown away as litter, which can then wind up in our water systems.
For the tonnes of plastic that are washed away into the ocean, ultraviolet radiation from the sun is the main factor influencing degradation. The decomposition process of plastic involves the long, complex polymer chains of the material being separated into smaller chains through a process known as chain scission, whereby the linkages holding the atoms of the material together break.
Over time, this breaks the polymers into smaller components, including monomers in the cases of plastics like poly(alphamethylstyrene) that often exhibit end-chain scission. As these bonds break, the physical characteristics of the materials change, and the plastic deteriorates into fragments.
And, although it can take more than 450 years for plastic to fully degrade, the process of chain scission happens at a much faster rate, with the first chains breaking in under one year.
In our waterways, this poses two fundamental problems. The first is that the smaller the polymer debris, the easier it is for organisms to ingest. A study by The University of Exeter and Plymouth Marine Laboratory found plastic, microplastics and other synthetics in the stomachs of all 102 of the sea turtles in the study. Plastic ingestion can be life-threatening, a scary thought when many sea turtle species are already considered endangered.
The second problem posed by plastic degradation in our waters is that of the chemicals produced during chain scission. One of the most notorious examples of the chemical by-products of plastic degradation is bisphenol-A, commonly known as BPA. This is an industrial chemical used in the processing and manufacturing of plastics, and it’s widely considered to be toxic.
From sea to land
For the plastics that stay on land and are buried in landfill, the process of degradation is similar. As many pieces of plastic waste in landfill will not be exposed to sunlight or UV radiation in the same way as sea plastics, the factor affecting degradation is heat.
As a dumping ground for waste, landfills contain a mix of many types of solid waste, most of which does not have the same trouble degrading that plastics do. As these products deteriorate, the chemical reactions that occur lead to an elevated temperature, which can contribute to polymer breakdown. However, the same problem of potentially toxic chemical leakage persists, which can easily enter soil and make its way back into our food chain over time.
Nature finds a way
Plastics and plastic pollution are clearly among the top problems facing the planet and life as we know it today. As such, researchers around the world have been vehemently searching for a solution, which led to the development of bioplastics and biodegradable plastics.
Following years of research, Teysha Technologies has achieved a landmark breakthrough in creating a viable substitute for existing petroleum-based polycarbonates from agricultural waste and natural feedstocks.
The breakthrough is more of a platform than a single polymer system, providing inherent versatility in the properties that can be achieved. It can be thought of as a plug-and-play system where various modified natural-product monomers and various co-monomers can be used. In addition to co-monomers, additives can be incorporated to modify the properties of the final polymer produced. This versatility allows for the formation of a variety of materials that can vary greatly in their thermal and mechanical properties.
The platform has already allowed for the development of a new kind of polymer, which we are currently referring to as AggiePol. The versatile material could replace the traditional plastic used in the automotive industry and medical equipment, and longer term could unlock the door to mastering environmentally friendly single-use packaging.
Teysha’s biopolymer degrades naturally over a period of months or years, depending on the polymers used in its composition and environmental temperature. Importantly, it does not require industrial catalysts to help it break down. A straightforward degradation process is one factor that could make fit for purpose with our current recycling infrastructure.
New materials are the pragmatic solution for consumers, material scientists and design engineers alike. Not only can they accommodate for the existing lifestyle of the end user, but also allow materials scientists to create something that serves as a desired, drop-in replacement for petroleum-based plastics. To find out more, visit Teysha’s website.
Contact Details and Archive...