Advancing the use of CO2-sourced activated cyclic carbonates for the synthesis and recycling of heteroatom-rich polymers

The remarkable diversity of plastics, offering immense versatility in properties across numerous applications, positions them as fundamental materials in the worldwide everyone’s daily life. However, their substantial growing production from fossil sources has led to resources depletion and accumulation of plastic waste in landfills and oceans. Moreover, the unique and versatile properties of plastics, combined with their low production cost, position them as irreplaceable with a yearly growing demand.
There is therefore an urgent need for our society to re-think the plastics design through the valorization of wastes such as carbon dioxide (CO2) while considering their recyclability. Among the conventional plastics, heteroatom-rich polymers hold significant market importance due to their high tunability, which makes them ideal candidates for a wide range of applications. The most well-known families of these polymers include polyurethanes (PUs), polycarbonates (PCs), polyesters, and polyamides. PUs are typically synthesized from toxic isocyanates – hazardous compounds for both the human health and the environment. Current regulations are however pushing toward a drastic limitation on the usage of these substances.
The global long-term challenge is to develop sustainable and safe production of polymers under mild conditions from non-hazardous reagents and to offer recycling options for these materials.
The aim of this PhD thesis is to advance the fundamental chemistry of ⍺-alkylidene cyclic carbonates as CO2-derived building blocks toward unique macromolecular heteroatom-rich structures. Although our group has previously demonstrated a proof-of-concept for the synthesis of various polymer families from this technology, the thermal, mechanical, and chemical properties of the polymers remain largely unexplored. This thesis provides an in- depth study into the synthesis and characterization of novel polymers derived from ⍺-alkylidene cyclic carbonates, expanding the library of polymers that can be obtained from this versatile building block. Importantly, the work considers the end-of-life options for these polymers, ensuring they align with current environmental sustainability goals. Through this work, I aim to contribute to the global effort of finding sustainable alternatives to traditional plastics.
This work was financed by the Fonds National de la Recherche Scientifique (F.R.S-FNRS) in the frame of the CO2Switch project under grant T.0075.20.