The design of polymers from renewable sources or waste is one of the most intense fields of research in the circular bioeconomy. Phenols, terpenes, and vegetable oils are eligible raw materials for the manufacture of a variety of materials, including elastomers, plastics, hydrogels, and composites [1]. The phenol group confers to these natural compounds intrinsic antimicrobial and antioxidant activity, making them ideal candidates for biomedical applications and sustainable packaging.
Herein, natural phenols, including dihydrocaffeic acid (HCAF), tyrosol (Ty), and eugenol (EU), were investigated as building blocks for the synthesis of bioactive polymers, as a valorization of agro-food wastes. HCAF was used for chitosan functionalization [2] while Ty and EU [3] were first functionalized to introduce polymerizable moieties and then copolymerized at different molar ratios with selected cationic or functional monomers to tune the final polymers’ amphiphilic properties. Polymerization conditions were optimized to obtain either soluble or crosslinked hydrogel systems, while dispersion polymerization enabled the formation of nanogels. A comprehensive physico-chemical characterization of the obtained polymer systems, including thermal analysis, rheological measurements, and dynamic light scattering, was performed to study the structure-property relationship. Furthermore, antimicrobial and antioxidant properties were evaluated to relate bioactivity to polymer composition. Hydrogels were designed as bioactive coatings for antimicrobial and antioxidant protection in packaging or biomedical surfaces, whereas nanogels were tailored for drug delivery applications.

The research for sustainable and active packaging formulations is crucial to produce innovative materials that meet the requirements of circular design and allow a reduction of food waste/loss.¹,² Accordingly, this work focuses on innovative fully biomass-derived formulations of a furan-based polyester with antibacterial properties, which were successfully designed to be used in the field of food packaging. First, the selected homopolymer poly(trimethylene furanoate), PTF, was synthesized by two step melt-polycondensation. As preservative, nisin, a polycyclic antibacterial peptide produced by Lactococcus lactis,³ was added, in 0.05 and 2.5 wt% amount. The good dispersion of the additive inside the polymeric matrix was proved by scanning electron microscopy. Owing to the presence of nisin, hydrophilicity of the formulations increased, compared to pristine homopolymer, and their mechanical properties evidenced a modulation. At the same time, the thermal stability, which is a key feature of furan-based polyesters, was kept. The evaluation of the functional properties highlighted the preservation of excellent gas barrier characteristics of PTF. Last, by disc diffusion assay against Lactiplantibacillus plantarum and Listeria monocytogenes, it was proved that the addition of nisin allows for the implementation of antibacterial features, absent in the pristine polymer. PTF loaded with 2.5 wt% of nisin was tested also in ACE juice inoculated with Listeria monocytogenes: after 8 days, L. monocytogenes growth decreased under the detection limit in the sample containing the active formulation, while in the control (polymer without nisin) the pathogenic species remained constant during the test.
(The authors thank the PNRR project CN AGRITECH)

Thermoplastics and thermosets are widely used in various applications, such as packaging materials and construction, due to their excellent properties like lightness and versatile processability. However, a significant issue arises from their fossil-based origins, with Europe being particularly dependent on imported crude oil. To mitigate the negative environmental impact of fossil-based raw materials and enhance Europe’s self-sufficiency, there is an increasing focus on utilizing available biomasses and developing high-performance biobased alternatives.

Furfural is a platform biochemical that can be efficiently produced from hemicellulose-based C5 sugars derived from industrial side streams and agricultural residues like straw. Historically, furfural has had limited applications, primarily as a raw material for producing furfuryl alcohol. Its potential as a raw material for polymers remains underexplored and poorly documented, likely due to its monofunctional nature compared to the dual functionality of 5-(hydroxymethyl)furan-2-carbaldehyde (HMF).

Our research team has developed several furfural-derived monomers that can be used to produce new thermoplastic and thermoset materials. Notably, 2,2’-bifuran-5,5’-dicarboxylic acid (2,2’-BFDCA)¹,², 3,3’-bifuran-5,5’-dicarboxylic acid (3,3’-BFDCA)³, 5,5’-sulfanediyldi(furan-2-carboxylic acid) (SFA)⁴, and 5-[(2-hydroxyethyl)sulfanyl]furan-2-carboxylate (MSF)⁵ have shown highly promising properties. This presentation highlights the latest discoveries, properties, and prospects of furfural-derived polyesters and resin materials, such as epoxy and vinylester resins. The results clearly demonstrate that novel biobased materials can possess fully competitive properties compared to currently used fossil-based materials.

We live in a world where electronic is so well integrated into our lives that it would be hard to imagine a single day without the support of modern technology (mobile phone, LED screen, camera, etc.). These electronic products have become essential tools in our daily routine. However, even if the electronic elements that compose them are more and more efficient, the fact remains that their lifespan is limited and that the resources used for their manufacture are demanding on the environment. A drastic change in the way we harness resources and manage electronic waste is required to minimize negative impacts on our environment. In order to eliminate electronic waste, materials from renewable and recyclable sources are sought. In this regard, the biomass is considered the only sustainable source of organic carbon and therefore the ideal replacement for petroleum products for the production of chemical compounds.
One of the resources derived from biomass, lignocellulose, is the most abundant bio-based material on earth. Indeed, the main value-added compound obtained from the depolymerization of lignin is vanillin. Vanillin is an aromatic compound with three functional groups which can be chemically modified (the methoxy group, the aldehyde function, and the hydroxyl group. The present work describes how vanillin can be expanded into several heterocycle building blocks for the preparation of sustainable polymers. Vanillin-derived polymers will be discussed as semiconducting polymers for optoelectronics applications.

High-performance energy storage materials are crucial for advancing the global energy transition. In capacitors, achieving high energy densities remains challenging due to the limitations of low dielectric constant materials, which constrain efficiency in high-power applications. To address this, we leveraged a molecular design that enhances polarizability across multiple length scales, through electronic polarization (aromatic groups), atomic and orientational polarization (polar functional groups), as well as by introducing progressive polarization vectors (uneven-numbered building blocks) in the amorphous and crystalline phase. 2,5-furan dicarboxylic acid (FDCA) is a uniquely fitting building block towards this purpose. It provides high thermo-mechanical properties as required, and has been used to synthesize polarizable polyesters, including polypropylene furanoate (PPF) and polyneopentyl glycol furanoate (PNF). Systematic investigations of their thermal and dielectric behavior reveal that, while structurally similar, PPF and PNF exhibit distinct crystallization behavior and unique temperature dependencies in crystal phase formation. Furthermore, we disclose how these properties can be tailored to affect the formation of polarizable crystal phases, ultimately enhancing the energy storage potential of this promising class of polymers beyond that of conventional fossil-based alternatives such as PET.

2,5-Furandicarboxylic acid (FDCA) has been recognized by the U.S. Department of Energy (D.o.E) as one of the most promising biobased chemicals [1], particularly for its potential in polymer materials. It can be produced through fermentation and easily converted into dimethyl furan-2,5-dicarboxylate (DMF) [2]. Within the FURIOUS project, starting from DMF, we exploited the effectiveness of chemical modification to ecodesign biopolymers with tailored properties for biomedical and electronic packaging films. Chemical structure modulation (aromatic/aliphatic ratio, composition, density of ester groups, side chain introduction) allowed to control crystallinity degree, achieving transparency while modulating flexibility. The presence of aromatic furan structure is expected to provide resistance to sterilization (key parameter for biomedical applications) and maintain good O2 and H2O barrier properties.
After synthesis, all samples underwent molecular (via NMR, FT-IR and GPC analyses), thermal (using DSC and TGA techniques), morphological (through XRD analyses) characterization. The systems were then processed by extrusion to produce homogeneous films. The mechanical properties were measured using a dynamometer, and the films' barrier properties to O2 and H2O were also assessed.
The sterilization resistance (required for biomedical packaging) was tested by gamma ray irradiation up to 200 kGy, and its effects on molecular and mechanical properties were evaluated.

Acknowledgements: This project has received funding from the Bio Based Industries Joint Undertaking (JU) under grant agreement “GA101112541” project FURIOUS (Call: HORIZON-JU-CBE-2022).