Moving away from fossil fuels and preventing the accumulation of plastics in the environment are two increasingly obvious ways to help address the difficulty of climate change.
A 3D-printed “leaf” made with the new bioplastic. Image Credit: Alain Herzog (EPFL)
In that vein, there are substantial efforts taking place to help develop recyclable or degradable polymers that are made from non-edible plant material described as “lignocellulosic biomass.”
Producing inexpensive biomass-based plastics is no simple task, however. There is because traditional plastics are highly complex, as they integrate low cost, heat stability, mechanical strength, compatibility, and processability – features that any substitute plastic replacements should match or exceed.
However, researchers headed by Professor Jeremy Luterbacher at Ecole Polytechnique Fédérale de Lausanne (EPFL) School of Basic Sciences have been successful in developing a biomass-derived plastic, similar to PET, that fulfills the criteria for substituting various current plastics while also being more eco-friendly.
We essentially just ‘cook’ wood or other non-edible plant material, such as agricultural wastes, in inexpensive chemicals to produce the plastic precursor in one step. By keeping the sugar structure intact within the molecular structure of the plastic, the chemistry is much simpler than current alternatives.
Jeremy Luterbacher, Professor, School of Basic Sciences, Ecole Polytechnique Fédérale de Lausanne
The method depends on a breakthrough that Luterbacher and his collaborators reported in 2016, where adding an aldehyde could stabilize a few fractions of plant material and prevent their destruction at the time of extraction. By repurposing this chemistry, the scientists were able to reconstruct a new beneficial bio-based chemical as a plastic precursor.
By using a different aldehyde – glyoxylic acid instead of formaldehyde – we could simply clip ‘sticky’ groups onto both sides of the sugar molecules, which then allows them to act as plastic building blocks. By using this simple technique, we are able to convert up to 25% of the weight of agricultural waste, or 95% of purified sugar, into plastic.
Lorenz Manker, Study First Author, Ecole Polytechnique Fédérale de Lausanne
The all-around properties of such plastics could enable them to be utilized in applications varying from packaging and textiles to medicine and electronics. Earlier, the scientists have made packaging films, fibers that could be spun into clothing or other textiles, and filaments that are utilized for 3D printing.
The plastic has very exciting properties, notably for applications like food packaging. And what makes the plastic unique is the presence of the intact sugar structure. This makes it incredibly easy to make because you don’t have to modify what nature gives you, and simple to degrade because it can go back to a molecule that is already abundant in nature.
Jeremy Luterbacher, Professor, School of Basic Sciences, Ecole Polytechnique Fédérale de Lausanne
Journal Reference:
Manker, L. P., et al. (2022) Sustainable polyesters via direct functionalization of lignocellulosic sugars. Nature Chemistry. doi.org/10.1038/s41557-022-00974-5