A self-healing plastic biodegrades in seawater

Researchers hope the new material could replace conventional plastics in a range of products

Spotted: Humans currently produce more than 350 million metric tonnes of plastic waste annually, and all this waste poses a serious problem for the environment, the ocean, and humans, so developing greener alternatives is crucial. Now, researchers at the University of Tokyo have created an innovative plastic material that is both stronger and stretchier than existing ones. As well as being partially biodegradable, the novel material also remembers its shape and can be easily repaired using heat. 

The researchers made the plastic, named VPR (Vitrimer incorporated with Polyrotaxane), by adding the molecule polyrotaxane to an epoxy resin vitrimer, which is a type of plastic. They initially were looking to increase the toughness of vitrimers, which are commonly very brittle, but found that many other functionalities were also improved.  

The novel material holds its shape and has strong internal chemical bonds at low temperatures. However, at temperatures above 150 degrees Celsius, the bonds recombine and the material can be reformed and moulded into different shapes. This also means it can self-heal when heated. 

When VPR was put in seawater, the researchers found that a quarter of the materials biodegraded, with polyrotaxane breaking down into a source of nutrition for marine life. Vitrimers without polyrotaxane, by contrast, did not biodegrade at all. 

It’s hoped that VPR could help to bolster a more circular economy, as well as help existing products to last longer. According to the researchers, VPR could be used in everything from engineering and manufacturing to medicine and sustainable textiles. In cooperation with companies, the researchers will explore the feasibility of various applications and continue their lab research. 

Plastics are everywhere, from toys and clothes to electronics and vehicles. Springwise has spotted many alternatives to the material, such as bio-based food packaging and a flexible and biodegradable plastic that can dissolve safely in water.

Written By: Anam Alam