Poly(hydroxy urethane)s (PHUs) are gaining attention as sustainable alternatives to conventional polyurethanes. Their attractiveness lies in eliminating the use of toxic isocyanates and the potential to implement monomers derived from renewable resources. However, the synthesis of PHUs from bis(cyclic carbonates) and diamines is hindered by the low reactivity of the system. To address this challenge, various approaches, including the use of catalysts to enhance reaction rates, have been explored.

This study focuses on the investigation of amine- and bismuth-based catalysts in liquid PHU systems. The polymerization reaction was conducted using a plate-plate rheometer in rotational mode — a technique referred to as rheo-polymerization. The structure-property relationships of materials were described using FT-MIR and 1H NMR spectroscopies, as well as oscillatory rheology measurements.

Here, we explore rheo-polymerization as a functional method for small-scale screening of multiple catalysts. Materials, both catalyzed and non-catalyzed, synthesized at a moderate temperature of 80°C, exhibited similar structural characteristics. A comparison between the two catalyst types demonstrated the superior efficiency of Bi-based catalysts over amine-based ones, as evidenced by higher complex viscosity values. Importantly, no by-products, such as urea, were detected in the samples.

The application of bismuth-based organocatalysts offers a novel and promising approach to catalysis in PHU systems. Furthermore, preliminary rheological studies allow for optimizing reaction conditions and assessing system performance before scaling up PHU synthesis, which is crucial for advancing the field.

Acknowledgements: The research has received funding from the European Union’s Horizon research and innovation programs under Grant Agreement No. 101058279 (project SIMPLI-DEMO).

SalphCoX [Salph= N,N’-bis(3,5-di-tertbutylsalicylidene)-phenylenediamine, Co=Cobalt, X=Pentafluorobenzoate] is a feasible Schiff-base based initiator that has been used to terpolymerize propylene oxide, L-lactide, and carbon dioxide in order to synthesize a degradable Poly(propylenecarbonate-block-lactide) in one-pot one-step tandem polymerization. This polymer is an intriguing combination of a polycarbonate block giving it ductility and a polylactide block giving it enhance mechanical and thermal properties. These synergistic properties would make the final terpolymer a suitable candidate for biomedical applications. This was accomplished by designing a catalytic system that can ring open L-lactide and propylene oxide on its own.
Catalytic system was based on the derivatives of Salophen, also known as "ONNO type Schiff base". It has both Lewis acidic and basic sites. Salophens are planar complexes that use equatorial bonds to coordinate with the Lewis acid metal center, in this case cobalt. Pentafluorobenzoate, a weak nucleophile that serves as a Lewis basic site in this investigation, is axially connected to the cobalt metal center. The reaction is started by this weak nucleophile by opening the propylene oxide ring. Additionally, a coordination-insertion process is used to introduce L-lactide and carbon dioxide into a polymer chain. To successfully synthesize a terpolymer, the synthesised initiator along with co-initiator, bis(triphenylphosphine)iminium chloride, are fed into an autoclave reactor in a fixed monomer-to-initiator ratio and a fixed initiator-to-co-initiator ratio. For structure elucidation, the catalyst and polymer were both characterized using 1H-NMR, 13C-NMR, and FT-IR. Size Exclusion Chromatography (SEC) was used to confirm the polymer's molecular weight and polydispersity.

The reliance of plastic synthesis on fossil fuels is highly unsustainable. Polymers from renewable sources such as sugars are a highly attractive alternative due to their functionality and abundance. Poly(lactic acid) (PLA) is a commercial bioplastic made from the ring-opening polymerisation (ROP) of L-lactide[1] and is currently one of the most successful commercially available sustainable polymers.[2] PLA’s low melting point and high mechanical strength make it an attractive alternative to traditional plastics in applications such as 3D printing and packaging.[3] However, PLA has a fairly simple polymer structure with little functionality, therefore limiting its applications and degradation potential.
Our group has been focusing on synthesising and investigating sugar-based monomers. These are bio-compatible, biodegradable and are highly functional. By adding these sugar units into PLA, their desired properties can be incorporated to the resulting copolymer. This presentation focuses on the ring-opening copolymerisation (ROCOP) of L-lactide with sugar-derived comonomers. The conditions of this reaction have been optimised; varied temperatures have been investigated, along with varied comonomer ratios. The influence of the composition of the copolymers on thermal stability and mechanical properties have been explored.

Adhesives are extensively employed across various industries reaching from simple packaging, to automotive construction and slip construction of microelectronics.¹ This versatility is due to their tunability, allowing for the adjustment of diverse properties. The class of scalable adhesives with the strong adhesive properties of thiol-catechol connectivities (TCC) originally emerged from mussel-inspired catechol-based adhesives.² TCC-polymers can be accessed by thiol-Michael polyaddition reacting multithiols with multiquinones. However, these adhesives rely on the use of Bisphenol A,³ a petroleum-derived compound of concern as it might act as an endocrine disruptor, highlighting the need for eco-friendlier and safer alternatives.⁴
Here, we summarize our efforts to introduce a bio-based adhesive derived from caffeic acid, a naturally occurring and non-toxic compound. Utilizing this bio-based monomer instead of conventional petroleum-based chemicals not only diversifies the TCC-monomer platform but also introduces advanced properties. Specifically, the methyl ester of caffeic acid can undergo a reversible photodimerization reaction under irradiation with UV-A and UV-C.⁵ Utilizing this property, we synthesized a caffeic acid-derived bisquinone that can undergo a Michael-type reaction with thiols to form the TCC moiety. The formation of TCCs was proven using model reactions with monothiols. Furthermore, the bisquinone was applied to dithiols, leading to polymer formation. The successful TCC formation was confirmed through 2D-NMR spectroscopy, fourier-transform infrared spectroscopy and matrix-assisted laser desorption/ionization. The resulting polymer adhesives were investigated showing exceptional high shear strengths on aluminum, exceeding the performance of bisphenol A-based adhesives and showcasing the potential of this bio-based approach as a sustainable alternative to conventional adhesives.

Polymers derived from amino acids, including polypeptides, have undergone notable development due to their broad application in biocompatible materials and useful chemical materials. For example; biodegradable and water-soluble polymers incorporating amino acids can be synthesized, with those containing amino acids in the main chain demonstrating high biodegradability. Moreover, such materials have been successfully developed as models for silk-based materials using amino acid-based copolymers [1]. Considerable efforts have been directed toward utilizing enzymes as catalysts for the synthesis of amino acid-based polymers and polypeptides, motivated by the need for eco-friendly processes and reduced energy consumption. While enzymatic catalysis typically occurs under milder reaction conditions, synthesizing high-molecular-weight polymers presents a notable challenge [2]. Previous research demonstrated the papain-catalyzed homopolymerization of amino acids such as leucine, tyrosine, phenylalanine, and tryptophan, as well as binary, ternary, and quaternary copolymerizations [3]. Despite these efforts, the synthesis of high-molecular-weight polymers was not achieved. However, this approach suggests a promising pathway toward peptide macromonomers that could be employed in subsequent polycondensation reactions, potentially leading to high-molecular-weight polycondensates. In this study, we aim to synthesize oligomeric peptide sequences via enzymatic polymerization as precursors for further post-condensation processes. This strategy is advantageous due to the biodegradable nature of polycondensates containing amino acid residues such as L-leucine, L-alanine, and L-phenylalanine. Given the non-toxic, biodegradable, and biocompatible properties of α-amino acids, our work aspires to contribute to the synthesis of more sustainable and biodegradable materials.

Sustainable composites made from renewable materials, industrial wastes and biopolymer matrices are of particular interest due to their potential to reduce environmental impact and promote an efficient circular economy. In this work, sustainable composites based on biodegradable poly(butylene succinate) (PBS) and cellulose-rich particles produced by sustainable hydrothermal treatment of wood waste (HTC) were formulated at different PBS/HTC ratios by micro-compounding. The durability and performance of the PBS/HTC composites were investigated considering different environmental conditions. In particular, composite materials were subjected to analysis of their rheological and thermal behavior, morphologies and mechanical properties. In addition, a comprehensive biodegradation study was carried out under different environmental conditions, including soil, freshwater, and seawater exposure. The degradation process was periodically monitored using different analytical techniques, such as weight loss measurements and Fourier Transform Infrared Spectroscopy (FTIR) analysis to monitor structural changes. The results obtained show that the HTC particles could influence biodegradation of the PBS matrix. These results highlight the potential of these bio-composites as a promising alternative to conventional plastics, contributing to reducing plastic pollution. Moreover, the incorporation of particles from wood waste can support the transition from a traditional linear to a more efficient circular economy.

Glycopolymers are valuable materials in biomedical applications such as drug delivery and biosensing, due to their ability to mimic biological carbohydrates. While glycopolymer synthesis has traditionally relied on non-enzymatic methods, these approaches often involve harsh reagents and generate undesirable byproducts. In recent years, the use of enzymatic strategies have gained increasing attention as a more sustainable alternative. In this work we focus on enzyme assisted synthesis of glycopolymers and glycomonomers, with the latter serving as the fundamental building blocks that determines the structure and functionality of the final polymer. To synthesize the glycomonomers,, we use (-glucosyloxy)ethyl acrylamide (Glc--EAAM) and 2-(β-manno(oligo)syloxy) ethyl methacrylates (Man --EMA) together with β- glucosidase and β-mannanase respectively to catalyze the reaction1,2. While Glc--EAAM was successfully synthesized in an earlier study , the synthesis of mannose-based glycomonomers (Man --EMA) presents challenges due to inconsistent β-mannanase activity, which has led to further optimization of the reaction conditions and enzyme selection. Advanced polymerization techniques, including RAFT and enzymatic polymerization were employed for the synthesis of glycopolymers, which were then analyzed by NMR, SEC and their thermal properties studied via TGA and DSC. This enzyme driven approach demonstrates a sustainable and effective strategy for glycopolymer synthesis, paving the way for next-generation biomaterials with enhanced functionality and sustainability.

In recent years, there has been increasing interest in replacing nonbiodegradable petroleum-based plastics with sustainable alternatives in the area of polymer research to address plastic waste worldwide. [1-2] However, it is a challenge to find biodegradable alternatives to current industrially available plastics, which have better mechanical properties than less durable biodegradable alternatives.[3] To overcome this challenge, we propose combining biodegradable biobased polyesters with mechanically strong biobased polyamides and synthesizing a range of poly(ester amide) (PEA) copolymers with different amide/ester ratios. Biobased aliphatic dicarboxylic acids, diols and diamines with 4, 5 and 6 carbon chains were selected as monomers. Melt polycondensation is utilized to synthesize the copolymers, and the resulting PEAs are characterized via 1H-NMR, GPC, DSC and TGA. Enzymatic degradation studies of the copolymers were also conducted, and the resulting degradation products were analyzed via LC‒MS. Future work will involve conducting standardized biodegradability tests to further assess the polymeric materials. The resulting poly(ester amide)s have potential applications in high-quality yarns, monofilaments, and synthetic fibers.

Polycarbonates (PCs) are a family of thermoplastics employed in various rigid plastics applications, such as construction materials or electronic devices. Nowadays, the most conventional way to produce PCs is the polycondensation of diols and phosgene or its derivatives. The toxicity of the reagents (phosgene, Bisphenol A) and the undesirable elimination of condensation products make this process rather unsustainable, and not adapted to the production of thermoset coatings.
This research project focuses on developing sustainable circular polycarbonate-based thermoset coatings. It is based on highly reactive CO₂-sourced cyclic carbonates, previously developed in the Detrembleur research group¹ ². These CO₂-based building blocks react with biobased polyols by a step-growth type reaction which occurs quickly with a small amount of an organocatalyst, and under solvent-free conditions at ambient temperature. The functionality of the polyols can be modified such that linear polycarbonates are produced with diols and cross-linked polymers when increasing the functionality of the alcohol. The facile handling of this polymerization process opens new fields of applications for polycarbonates, for example coatings or elastomers. Moreover, the chemical recycling of these polycarbonates can be realized by facile and fast aminolysis³ or hydrolysis, allowing the recovery of molecules of interest for further polymerization or upcycling. This research project aligns well with the principles of green chemistry, focusing on CO₂ valorization, employing mild reaction conditions, and promoting polymer circularity for enhanced sustainability.

The energy crisis has led to the development of new technologies for renewable energy production, with solar cells emerging as a promising alternative. However, many of the active materials in these devices are vulnerable to moisture and other environmental factors, necessitating protective encapsulation.¹ Encapsulant materials have to withstand extreme conditions as low as -40 °C without losing their mechanical properties or becoming brittle. Therefore, commercially available polymers with low glass transition temperature (Tg), like ethylene-vinyl acetate (EVA), have been extensively used.² However, their petroleum-based origin represents a major drawback and new sustainable options are required. 2,5-bis(hydroxymethyl)furan (BHMF) is arising among the bio-based monomers, but its potential has yet to be fully explored. Previous studies have shown that BHMF-based polyesters exhibit a low Tg³, demonstrating their capability for this application. Additionally, the incorporation of an amide bond in polyesteramides was proven to enhance the material's mechanical strength and stability.⁴
In this study, BHMF-based polyesteramides are proposed as promising biobased alternatives for use as solar cell encapsulants. BHMF was polymerized with dimethyl adipate (DMAd) and a series of aliphatic diamines in bulk through enzymatic polymerization. This synthesis method uses milder conditions to preserve BHMF, which is thermally unstable. The thermal and mechanical properties of the resulting materials were tailored by adjusting the feed composition and varying the chain length of the aliphatic diamines. The obtained polyesteramides were thoroughly characterized and compared with conventional polymeric materials used in photovoltaic encapsulant applications.

Organocatalyzed ring-opening polymerization (ROP) has emerged as a versatile strategy for synthesizing polymers from carbocyclic or heterocyclic monomers, offering significant sustainability advantages such renewable resource derivation, ease of hydrolytic degradation, and excellent biocompatibility.1,2
Recently, Waymouth and coworkers introduced bisurea (di)anions as a novel class of organocatalysts that are fast, easily tunable, mildly basic, and exceptionally selective.3,4
Using Density Functional Theory (DFT) calculations, we elucidated the catalytic mechanisms, revealing that the remarkable activity and selectivity of these systems arises from the cooperativity of the H-bonding sites, reaching optimal efficiency when an ortho-phenylene linker places the ureas in close proximity and electronic conjugation (Figure 1). Additionally, the semi-rigid linker is crucial in creating a catalytic pocket that is both tight and flexible, effectively facilitating the ROP of ε-caprolactone (ε-CL) by suppressing competitive transesterification reactions and ensuring high process selectivity.
This study offers valuable insights into exploiting cooperativity as a powerful strategy to address more challenging polymerizations or organic transformations involving anionic transition states.

The food packaging industry is a major source of global plastic waste due to the short lifespan of these materials, creating a significant environmental challenge. Bio-based polymers from renewable sources have emerged as sustainable alternatives to fossil-based plastics. Among them, tannins are particularly promising due to their abundance, low cost, and antioxidant, antibacterial, and photoprotective properties. However, tannin-based biofilms alone lack the mechanical strength required for food packaging, necessitating their combination with film-forming biopolymers such as chitosan.

This study explores the enzymatic graft polymerization of tannins onto chitosan using laccase enzymes, a process that offers environmental benefits by operating under mild conditions, eliminating the need for organic solvents, and reducing energy consumption. This environmentally friendly method provides an effective strategy for developing advanced materials suitable for food packaging applications.

The aim was to synthesize chitosan-tannin biofilms by enzymatic polymerization to obtain materials with improved mechanical, thermal, antioxidant and photoprotective properties. The copolymerization of chitosan and tannins, catalyzed by laccase enzymes, resulted in biofilms with significant improvements in mechanical and thermal properties compared to the base polymers, along with strong antioxidant capacity.

The results indicate that the synthesized biofilms are promising for creating sustainable and functional food packaging, capable of extending product shelf life while reducing dependence on conventional plastics. This study highlights enzymatic polymerization as a green and efficient approach to develop innovative biopolymer-based packaging materials.

A novel approach that convers biowaste into biopolymers and more specifically PHAs, through the co-production of bioenergy (green production of hydrogen) in a balanced manner will be presented. This approach aims to reduce the overall PHAs production cost on both a laboratory and a pilot plan scale, paving the way for its wider use in a plethora of applications. Dark fermentation was optimized to convert heterogeneous organic waste (including municipal organic waste and agro-industrial waste streams) to bio-hydrogen and volatile fatty acids (VFAs). The potential of the obtained VFAs to act as sole carbon source for various fermentation approaches is being optimized for the synthesis of targeted -industrially relevant- PHAs. Tailored PHAs (derivatives and blends with synthetic biodegradable polymers such as PCL, PLA and PVA) are also being produced with the aim to improve the performance and to offset the high price of PHAs.

Efficient, durable, and customizable light-emitting diodes (LEDs) are of current research and industrial interest for advancing solid-state lighting. Among them, polymer LEDs (PLEDs) stand out due to their high processability, simple fabrication, and large-area applications.
We focus on soluble, scalable, high molecular weight fluorescent aromatic polyethers, synthesized without precious metal catalysts or tedious purification steps¹. By incorporating blue, yellow, and orange-red fluorescent monomers, we achieve polymers with stable and tunable light emissions². Additionally, we develop high molecular weight polymeric phosphors using iridium complexes³, to exploit the triplet excitons of Ir-based complexes.
To enhance the sustainability of these polymers, water/alcohol solubilizing units are utilized to meet the green and eco-friendly solubility requirements for the fabrication of PLED devices. The solubility of these polymers in polar non-chlorinated solvents (e.g., DMF, NMP) and greener alternatives (e.g., 2-MeTHF, water, ethanol) has been studied.
By fine-tuning the emission properties, we achieve full-spectrum coverage, including white light emission. Their high molecular weight and solubility enable solution-based deposition and printing, paving the way for printable wide-panel and signage PLEDs.
Acknowledgements
This research has been co‐financed by the Greece 2.0-National Recovery and Resilience Fund: "Development of efficient third generation PV materials and devices to enhance the competitiveness of enterprises to the green energy production"_3GPV-4INDUSTRY. TAEDR-0537347, and by the European Union and Greek national funds through the Operational Program Competitiveness, Entrepreneurship, and Innovation, under the call RESEARCH – CREATE – INNOVATE (project code:T1EDK-01039 “Printed OLEDs for Intelligent, Efficient & Tunable solid-state lighting devices in Large Scale”, APOLLON.

Dynamic covalent networks (DCNs) represent a swiftly evolving class of covalently crosslinked polymers with the capacity for network rearrangements triggered by external stimuli such light or heat. Expanding our previous work on DCNs involving neighboring group participation using phthalate monoesters, we now report dynamic polycaprolactone (PCL) networks based on mellitic anhydride (MA). These networks were successfully prepared via reactive extrusion and showed full stress relaxation at elevated temperatures. It was established via rheological and VT-IR measurements that stress-relaxation occurs through a dissociative mechanism via the intra-molecularly catalyzed formation of cyclic anhydride groups, similar to the previously reported phthalate monoester dynamic networks.
Similar to what was observed in our previous studies using pyromellitic dianhydride (PMDA), the PCL-MA networks suffer from side reactions which reduce the dynamics of the networks. It was shown that the main side reaction is the reaction of free hydroxy-end groups with the free carboxylic acid groups resulting in diester groups, which cannot undergo the cyclic anhydride formation, leading to poorer stress relaxation at elevated temperatures. Counterintuitively, this effect could be counteracted somewhat by increasing the number of free hydroxy groups within the network, and a more consistent stress relaxation was observed upon repeating stress relaxation experiments. These and our more recent results will be presented.

When mixed with reinforcing agents to produce composite materials, thermosets can be exploited in many industrial fields, such as interior decoration, aircraft part manufacturing, and renewable energy (wind turbine blade manufacturing). Thermosets have outstanding thermomechanical properties despite the impossibility of recycling; thus, when thermoset composite materials reach their end-of-life (EoL), their management becomes crucial. In fact, a technique often employed to cope with thermoset waste is landfilling, which has a negative impact on the economy and the environment [1].
To overcome the sustainability issues of thermosets, new materials based on dynamic covalent chemistry called vitrimers are being investigated. Vitrimers can be considered a “bridge” between a thermoset and a thermoplastic material, where unlike the aforementioned thermosets, thermoplastics can be recycled owing to the absence of cross-links. Vitrimers have the outstanding feature of being reprocessable owing to the presence of dynamic cross-links. The covalent adaptive behaviour can be triggered by the action of light and/or temperature. it allows the material to flow like glass (hence the term “vitrimer”), enabling its reprocessability [2],[3].
This project aims to exploit vitrimer chemistries to manufacture catalyst-free vitrimer-based composites from biobased raw materials and/or commercially available materials. To obtain such materials, different exchange mechanisms have been investigated such as transimination, transesterification, and oxime metathesis [4],[5]. To manufacture such composites different elements have been used such conventional reinforcing fibers such as carbon fibers; glass fibers; and biobased fibers such as flax fibers, kenaf fibers, and Sisal fibers.
This work could help reduce pollution by increasing composites’ reprocessability.

Eutectogels are an emerging class of materials, that holds great promise for application in soft electronics. However, they suffer some limitations, being generally unable to display autonomous self-healing in submerged and humid environments, failing to undergo closed-loop recycling.1, 2 Here, an adhesive eutectogel able to self-heal in air and underwater, exhibiting room-temperature recyclability, and possessessing high transparency, was synthesized via one-step photopolymerization with physical crosslinking in a unique deep eutectic solvent (DES) system. The eutectogel could achieve closed-loop recycling without affecting its mechanical properties and adhesive performance. By balancing hydrophilic and hydrophobic moieties, which interact through hydrogen bonding, electrostatic interactions, and hydrophobic associations, the resulting eutectogel demonstrates excellent mechanical properties and environmental stability across a wide temperature range and under harsh conditions. This unique DES system enables synergistic interactions between hydrophilic and hydrophobic monomers, offering a universal strategy for eutectogel fabrication. The presence of freely mobile ions allows the gel to function as both a strain and pressure sensor in air and underwater, including applications in human motion sensing and information transmission, highlighting its immense potential for multifunctional sensing and wearable electronics.

The development of self-healing polymeric materials is gaining increasing interest in the aerospace field, particularly for lunar exploration missions. Spacecraft and equipment operating on the Moon are continuously exposed to extreme conditions, including micrometeoroid impacts and abrasive lunar dust, which can cause surface damage over time. This work focuses on the fabrication and characterization of polyimide-based materials with intrinsic self-healing properties and shape memory functions. To ensure a more sustainable approach, a bio-based solvent, dimethyl isosorbide (DMI), was used for the synthesis of the poly(amic) acids, which were subsequently imidized by thermal treatment. Traditionally, the synthesis of these polymers relies on solvents that are toxic to both human health and the environment. Our chemical approach involves replacing these hazardous solvents with greener alternatives. The aim is to achieve material properties and performance similar to or better than those obtained with traditional solvents, ensuring suitability for use in space environments. To enhance the self-repairing ability, boric acid (BA) was incorporated into the polymer matrix, enabling healing through strong hydrogen bonding interactions. Additionally, the introduction of trifluoromethyl groups improved flexibility and mechanical performance. Structural and surface characterizations confirmed the successful synthesis and functional properties of the membranes. Additionally, shape memory behavior was demonstrated, allowing the material to autonomously recover its original form. The findings suggest that these polyimide materials have great potential for extending the durability of space structures, minimizing maintenance efforts, and improving mission reliability.