A team from the Swiss Federal Institute of Technology in Lausanne (EPFL) has developed a new type of plastic derived from vegetable waste. With similar properties to PET, it can be chemically recycled or degrade in the environment as sugars.
Impressive properties
Featured in the magazine Nature Chemistryle material draws its resistance from lignin, a biopolymer that makes up the rigid wall of plant cells. Previously, Swiss researchers had developed a method of ” cooking » inedible plant matter using inexpensive chemicals to extract lignin to produce a precursor to plastic. Their new work involved a related chemical to make a more versatile bioplastic.
« Using a different aldehyde [l’acide glyoxylique au lieu du formaldéhyde] we were able to attach ‘adherent’ functional groups to both sides of the sugar molecules, then allowing them to behave like LEGOs “, Explain Lorenz Manker, co-author of the study. ” This technique can convert up to 25% of the weight of agricultural waste, or 95% of purified sugar, into plastic. »
The resulting material has properties similar to conventional plastics. It withstands temperatures up to 100°Chas a tensile strength of up to 77 MPa, a stiffness of up to 2,500 MPa and constitutes a good gas barrier (oxygen, water vapour, etc.). Particularly versatile, it can be used to make food packagingof the filaments for 3d printing or some spunnable fibers to create clothing and other textiles.
A bioplastic that can be more easily produced on a large scale
The ecological dimension of the material is not limited to the techniques used to obtain it: it can be chemically recycled using the process currently used to recycle PET plastics, and will degrade into plant sugars rather than microplastics if it finds its way into the environment.
And different bioplastics are currently under development, scaling up to full-scale production is a daunting challenge. According to the Swiss team, the chemical process required to obtain this new material turns out to be much less complex, and involves inexpensive and widely used compounds.
« What makes it unique is the presence of the intact sugar structure “, highlighted Jeremy Luterbacher, also co-author of the study. ” This makes it incredibly easy to manufacture, as there is no need to modify what nature gives us, and simple to degrade, as it can revert to a molecule that is already abundant in the environment.. »