Researchers at Lund University in Sweden have produced a plastic based on indole, a hydrocarbon that is present in human faeces.
Chemical engineering doctoral student Ping Wang produced the plastic, which was found in lab experiments to be more durable than both regular plastic and other bioplastics, while also potential being better suited for recycling.
The success PEF, which instead of oil contains the hydrocarbon furan, made researches at Lund University interested in other renewable materials that could potentially be used for plastic production.
Indole is a heavier hydrocarbon than furan, and while being found in faeces, is also found in certain flowering plants.
The research team are thought to be the only one researching indole polyesters, and have shown promising results.
A regular PET bottle’s glass-liquid transition temperature, where the material softens and deforms, is 70 degrees, with the most successful PEF experiments can withstand around 86 degrees.
However, the indole plastic developed by Ping Wang is stable up to 99 degrees.
Associate Professor Baozhong Zhang, who supervises the research team, said: “These are preliminary results, but we have seen that polyester plastic has better mechanical properties, which makes it more sustainable. This can lead to better recycling in the future. At present, PET bottles can only be recycled once, then they must be used for something else such as textiles.”
Currently indole is only produced on a small scale and mainly used in perfume and drugs, and while it may be possible to use bioengineering methods to produce indole from sugar through fermentation, such a process would first needed to be analysed more thoroughly before the production cost can be calculated.
