Upcycling of Plastic Blends via Reactive Extrusion – UpCycle

Plastics are light, tough, durable, and their processing energetically less demanding than most other raw materials. Yet, the current economy of plastics is far from being sustainable, with only 8.3% of the 391 million tons of plastics produced worldwide in 2021 coming from post-consumer recycled polymers. Of the various technologies available to manage the end-of-life of plastics, mechanical recycling is the most effective method in terms of time, economic cost, carbon footprint and environmental impact. The main drawback of mechanical recycling is that it produces materials with inferior mechanical properties compared to virgin materials, mainly due to the presence of incompatible polymer contaminants in the recyclates. Polyethylene (PE) and polypropylene (PP), which alone account for more than half of the world's primary polymer production and waste generation, are the most critical example, with an estimated 95% loss of value after recycling. Developing efficient solutions for the mechanical recycling of polyolefin blends is therefore a major scientific and societal challenge.
With the UpCycle project, we intend to develop a family of grafting agents to upcycle post-consumer blends of PE and PP into recyclable dynamic polymer networks, by reactive extrusion. We plan to develop novel experimental methods to investigate the reactivity of the grafting agents and to study the upcycled materials from the molecular to the mesoscopic scale. We also aim to develop a full structure-property relationship and to scale up the reactive extrusion process, both of which are essential for the development of this approach.
To achieve these goals, the UpCycle project is based on a multidisciplinary approach and will take advantage of the complementary expertise of ESPCI Paris (dynamic networks), ICR (quantum calculations and EPR spectroscopy), and CNAM (polymer processing and structure-property relationship).