A new type of plastic made from DNA may be the most sustainable plastic yet. Producers can use the material to make packaging and electronic devices biodegradable.
Chinese researchers have made the new type of plastic from DNA and vegetable oil. The plastic is reusable, its production is energy efficient and the material is also easy to recycle or break down.
Bad news
Most common plastics are bad for the environment. They are made from non-renewable petrochemicals, the chemical products of petroleum. Furthermore, high temperatures and toxic chemicals are required to make the plastic and it takes hundreds of years for it to degrade. But a small part of it is recycled. The rest ends up in the landfill, is burned or ends up in nature.
Alternative plastics, made from vegetable sources such as cornstarch or seaweed, are increasingly popular. They are sustainable and biodegradable. The disadvantage is that it also costs a lot of energy to produce these plastics. In addition, they are difficult to recycle.
Solution
synthetic biologist Dayong Yang from Tianjin University in China and his colleagues developed a type of plastic that circumvents these problems. The researchers linked small pieces of DNA together with a substance from vegetable oil. This resulted in a soft, gel-like material. If you pour that stuff into molds and extract the water with a special freeze-drying process, you can make all kinds of shapes.
The researchers made various objects in this way: a cup, a triangular prism, puzzle pieces, a dumbbell shape and also a model of a DNA molecule. Then the team recycled the objects by submerging them in water. This turned the solid structures back into a gel, which they could reuse to make other shapes.
Future
‘What I like about this type of plastic is that you can break it down and just reuse it,’ says chemist Damian Laird from Murdoch University in Australia, who was not involved in this study. ‘Most research focuses on developing bioplastics that are biodegradable. But if we are serious about the transition to a circular economy, we also have to make sure that they are recyclable, so that they are not lost.’
Another advantage of the new type of plastic is that the original material, namely DNA, is available in abundance. There is an estimated 50 billion tons of DNA present on Earth. Yang and his colleagues have used DNA from salmon sperm in this study, but DNA from sustainable sources such as crop waste, algae or bacteria is also suitable.
In addition, the production of the DNA plastic does not require high temperatures. Compared to polystyrene plastic, the production of this new type of plastic emits 97 percent less carbon. When the plastic is no longer needed, it can even be cleaned up using specific enzymes that break down DNA, Yang says. ‘To the best of our knowledge, the DNA plastic we describe here is the most sustainable of all plastics,’ says Yang.
New start
There are two drawbacks to the new type of plastic. For example, it is not as strong as traditional plastics. In addition, the material must remain dry in order not to turn into a gel again. That is why, according to Yang, it is especially suitable for processing in packaging materials and electronic devices.
To make the DNA plastic waterproof after all, material scientist suggests Maryan Naebe from Deakin University in Australia to coat it with a layer of water-resistant chemicals – just like we do with paper cups.
Yang indicates that his team is already making plans to make commercial products with the new type of plastic: ‘this is just the beginning.’
