Grape waste from wine making could lead to more durable plastics
In wine making, some 25 per cent of the grapes is left over composed of grape pomace (leftover grape skins, stems, and seeds), and lees. This waste material is rich in polyphenols. In the human body, these polyphenols play an important part in preventing or reducing the progression of diabetes, cancer, and neurodegenerative and cardiovascular diseases.
Plastics can become brittle when they have been exposed to light or air for too long. To prevent this, synthetic stabilisers are added. However, polyphenols can prevent brittleness in plastics as well.
The researchers placed residue of Pinot noir grapes in the microwave and then freeze-dried the remaining liquid. This was then turned into a powder and added to the molecular matrix of polypropylene, a plastic frequently used for packaging.
Under accelerated aging conditions, untreated plastics started to crack after 25 hours. Plastics infused with the grape material lasted twice as long. While the biobased additive isn’t as effective as commercial stabilisers, it has the benefit of being more eco-friendly. In addition, there is the potential to improve its performance.