Enormous quantities of commodity polyesters are discarded every day. While commercial recycling has improved in the last decade, significant portions of waste polyesters are still mismanaged and find their way into our natural environment. Furthermore, our current recycling technology is imperfect, and leads to polymer degradation and generation of microplastics. Chemical recycling has several advantages in this respect, but technological gaps still exist. Our work focuses on the chemical diversification of discarded polyesters into various high performance copolyester constructs. This presentation shows the versatility of the synthetic approach by showcasing various copolymer constructs and highlighting the different property profiles that can be accessed. In the end, we can transform commodity, post-consumer recycled poly(ethylene terephthalate) (rPET) into segmented copolymers that range from high modulus materials to flexible and stretchable elastomers. Furthermore, we have recently found that these complex upcycled thermoplastic copolyesters can themselves be chemically recycled, ensuring a fully circular polymer platform based on high performance materials. Such strategies are crucial for reducing the environmental burder of continued utilization of virgin polymer feedstocks and a linear, wasteful polymer manufacturing system.

The linear economic model, characterized by 'take, make, use, and dispose,' poses severe environmental challenges, prompting the EU’s Green Deal and Italy’s National Recovery and Resilience Plan to advocate for a transition to circularity. Among polymers, polypropylene (PP) is widely used but exhibits a low recycling rate (5%) due to separation difficulties, additive presence, and degradation during reprocessing. This study explores the recycling of post-use PP nonwoven textiles from disposable facemasks, leveraging mechanical recycling through extrusion reprocessing for additive manufacturing.
The facemasks, composed of 77% PP, underwent sanitization using steam, aqueous sodium hypochlorite, and ultrasound before being hot-pressed into sheets, ground, extruded, and pelletized. The process conditions included a hot-pressing step at 190°C for 5 minutes at 6000 Pa, followed by extrusion at 165–170°C with a torque of 10 Nm and 30 rpm.
Thermal, rheological, mechanical, spectroscopic, and calorimetric analyses assessed the degradation effects from both sanitization and melt blending. Results indicated that different sanitization methods led to varying degrees of polymer chain degradation, as evidenced by distinct crystalline formations in calorimetric curves and amplified degradation peaks in spectroscopic analyses. Despite degradation, the recycled PP demonstrated sufficient structural integrity for reuse, particularly when blended with virgin materials.
This study reinforces the viability of integrating recycled PP into additive manufacturing, supporting circular economy principles and enhancing waste valorization strategies.

Polymers play a crucial role in our modern life as no other material exists that is so versatile, moldable, and lightweight. Consequently, the demand for polymers will continue to grow with the human population, modernization and technological developments. Although polymers were never designed to be recycled, it is clear that a linear polymers economy is no longer sustainable. Of all polymers, polyolefins have the lowest life-cycle environmental impact and even outperform bio-based polymers. [1] However, polyolefins are chemically inert and reveal a low surface energy. Combining their excellent mechanical properties with the ability to adhere to other products or create nanostructured materials would widen the application window of polyolefins even more. [2]
During the presentation, of our personal account in the field of functionalized polyolefin synthesis and their application development will be presented. As the use of randomly functionalized polypropylenes is rather underdeveloped, as compared to the corresponding randomly functionalized polyethylenes, we focused on potential applications of the former material. Atactic or low crystalline hydroxyl and carboxylic acid-functionalized propylene-based co- and terpolymers form elastomers with interesting properties that can be influenced by enhancing the hydrogen-bonding within the system or by creating ionomers. Thus, the polar functionalities cluster together in domains that can host small polar molecules like for example a pH indicator affording useful sensors. The functionalized polyolefins can also be used as precursors for amphiphilic graft copolymers, undergoing self-assembly, and therefore being suitable for nanoporous membranes preparation as well as compatibilizers in various polymer blends. [3, 4]

The global waste rubber stream is substantial, with tires comprising the largest fraction at 1 billion objects annually. Built for durability, tires feature a metal and fiber skeleton encased in vulcanized rubber with carbon black and other additives. While this ensures longevity, it also complicates recycling. Mechanical recycling is mainly limited to whole-tire reuse or crumbed filler for asphalt [1] and, until recently, sports fields. In chemical recycling, the industry favors pyrolysis for naphtha feedstock and recovered carbon black (rCB), now gaining interest for reuse in tire formulations [2].
However, we recently expanded the opportunities. We extended the lifespan of crumbed rubber fillers by developing (recycled) polyethylene and polyurethane coatings that reduce heavy metal leaching, while enabling tunable elasticity [3]. Alternatively, we tailored ozonolysis as a sustainable chemical recycling method, developing a patented work-up process [4]. This heterogeneous three-phase reaction efficiently converts tire rubbers into platform chemicals such as levulinic and succinic acid, achieving high yields (55 m% of the rubber), as shown in the figure. The remaining fillers, recovered separately, contain 16 m% ash—comparable to pyrolysis rCB but free from heavy oils and PAHs. We further studied reaction progression in different environments, solvents, and temperatures to assess the impact of solubility and solvent swelling on the ozonolysis reaction rate.
It is clear that the race for the most optimal uses of this well-defined feedstock has just begun, with several hybrid technologies to come, as discussed in this work.

Global polymer production has increased exponentially since its start in the 1950s, reaching a total of 413 Mt in 2023 [1]. However, the vast majority of these polymers are non-biodegradable under environmental conditions nor adequately recyclable, which leads to their accumulation in landfields or leak into terrestrial or aquatic settings. An additional concern is that most of the currently produced polymers are fossil-based, so more sustainable alternatives are needed. In this vein, during the last decade, several biobased alternatives have emerged [2]. Among those are bio-based furanic polyesters such as poly(trimethylene 2,5-furandicarboxylate) (PTF) and poly(ethylene 2,5-furandicarboxylate) (PEF) [3], which have comparable mechanical properties to poly(ethylene terephthalate) (PET) and even enhanced barrier properties for packaging applications [4]. However, these bio-based alternatives keep raising the same environmental persistence challenges during their End-of-Life (EoL), and since current recycling processes are still poorly efficient, the development of alternative recycling approaches is of the utmost importance.
In this work, we report the design of a continuous, mild, and close-loop recycling approach applied to furanic polyesters by making use of the superior capacity of Deep Eutectic Solvents (DESs) to catalyse both alcoholysis and polyesterification reactions [5]. Both PTF and PEF were recycled using a urea-based DES reaching a maximum yield of 92% and 77% for PTF and PEF, respectively. The proposed recycling approach confirms the potential of DESs to catalyse de-/re-polymerization in a continuous way, as an efficient and greener option to chemically recycle persistent polyester wastes, promoting a more circular approach for its EoL.

Polyethylene terephthalate (PET) is the most produced fibre in the world, with a share of 57% of the global production, due to its good mechanical properties and low cost. Even if the 3Rs (Reduce, Reuse, Recycle) explain that it is necessary to rethink our way of consuming, recycling textiles into high-value materials is a major topic. Apparel is however closed-loop recycled to just about 1%, due, notably, to its complex composition [1].
The present study deals with chemical recycling of a cotton/PET fabric by alkaline hydrolysis, which can lead to nearly undegraded cellulose and, after treatment, to good quality terephthalic acid (TPA), one of the monomers of PET. The ideal case is to use this recovered substance to polymerize it again into a chemically recycled PET, but it requires obtaining specific properties related to purity and size and shape of the crystals [2,3].
The influence of precipitation parameters of TPA on its final properties, that are compared with a commercial material, is notably studied. After confirming by Infrared spectroscopy that TPA was formed, purity is assessed by Thermogravimetric Analysis, showing that produced and commercial TPA exhibit similar degradation (Figure 1) and High-Performance Liquid Chromatography. Moreover, the morphological and crystallographic properties are characterized by Digital (differences in grain size and shape are presented on Figure 1) and Scanning Electron Microscopy, X-Ray Diffraction and Differential Scanning Calorimetry. Polymerization into PET aims to be realized for several samples, intending to understand the key parameters for obtaining a high-standard recycled TPA for polymerization.