Novel 2,5-furandicarboxylic acid-based polyesters, by combining poly(octylene 2,5-furanoate) and poly(triethylene 2,5-furanoate), were successfully synthesized, characterized and evaluated for sustainable and flexible food packaging application. Three eco-friendly and solvent-free synthetic approaches, such as melt polycondensation, physical blending and reactive blending were employed to prepare: equimolar physical blend, 50 mol% of poly(octylene 2,5-furanoate) block and random copolymers, 80 mol% of poly(octylene 2,5-furanoate) random copolymer.After molecular characterization, by nuclear magnetic resonance spectroscopy and gel permeation chromatography, confirming the good control of synthesis parameters, the polymers were processed in form of films and subjected to solid-state properties characterization.High thermal stability was evidenced by thermogravimetric analysis, while the characteristic temperatures were determined through differential scanning calorimetry showing all the polymers, with the exception of poly(triethylene 2,5-furanoate), are capable of developing ordered structures. Diffractometric measurements showed poly(octylene 2,5-furanoate) crystals, in comparable amount but with different perfections degree, formed in all the crystalline samples.Scanning electron microscopy was employed to assess film microstructure, distribution and continuity.Functional properties, such as mechanical behavior and gas barrier capability, were tested and correlated with chemical, structural/microstructural and thermal characteristics of the polymer films.Surface wettability was measured and correlated with the composting ability and kinetics.In general, flexibility was enhanced while keeping the gas barrier ability even under humid conditions, while degradation rate in compost was properly tuned in the perspective of different end of life management of the polymer films.

Present research is focused on the preparation and characterization of bio-based polymer blends intended for sustainable food-packaging applications, starting from poly(butylene 2,5-furanoate) (PBF), characterized by very good barrier performance but quite high mechanical rigidity. In order to further improve gas permeability and increase its ductility, binary blends were prepared, combining PBF with varying amounts of poly(pentamethylene furanoate) (PPeF), another furan-based polyester with outstanding mechanical flexibility and gas barrier properties. The resulting materials were processed into compression-molded films and investigated through molecular, morphological, structural, thermal, and mechanical analyses. Blending turned out to be the winning tool in order to keep the high thermal stability of the reference homopolymers, increasing, at the same time, mechanical ductility and further lowering the permeability to oxygen and carbon dioxide compared to those measured for neat PBF. All these results were achieved without the use of any compatibilizer. Lastly, in order to test the end of life of these materials, composting studies were carried out, revealing a higher degree of weight loss for the blends compared with PBF homopolymer.

Autologous grafts remain the clinical gold standard for vascular reconstruction; however, their use is limited by donor site morbidity, poor availability, and long-term failure. Synthetic alternatives, while effective in large-caliber vessels, fail in small-diameter applications (<6 mm) due to thrombosis, intimal hyperplasia, and biomechanical mismatch. In this context, tissue-engineered vascular grafts (TEVGs) emerge as a solution, requiring biomaterials that closely replicate the structural, mechanical, and hemocompatible properties of native vessels. Aliphatic polyesters such as polylactic acid, polyglycolic acid, and poly(ε-caprolactone) are extensively studied but show poor endothelialization and mechanical deficiency. In contrast, poly(butylene trans-1,4-cyclohexanedicarboxylate) (PBCE) attracts interest for its biocompatibility, thermal stability, and processability. Its copolymerization with Pripol 1009, a commercial fatty diacid, enables modulation of mechanical properties and degradation rate, two of the key parameters for vascular engineering. In this work, electrospun scaffolds based on these copolymers are fabricated in flat and tubular formats and characterized in terms of morphology, mechanical behavior, hemocompatibility, and endothelialization potential. Certain formulations display mechanical properties comparable to native vessels, support endothelialization and smooth muscle cell adhesion, and do not trigger coagulation pathways in in vitro assays. These results identify PBCE/Pripol copolymers as promising candidates for next-generation TEVGs, bridging the gap between synthetic reliability and biological performance in small-diameter vascular applications.

In the present study, biobased nisin-containing formulations were prepared to obtain innovative, sustainable, and active food packaging. Poly(trimethylene furanoate) (PTF) was blended with three different amounts of commercial nisin powder (0.05, 1.0, and 2.5 wt %; Sigma-Aldrich, 2.5% active nisin, balance NaCl), corresponding to 0.0125, 0.25, and 0.625 mg of active nisin/g of polymer, respectively. Circular films (& Oslash; = 11 cm, thickness approximate to 200 mu m) were obtained by compression molding. The high thermal stability and barrier properties of PTF have been maintained, while mechanical properties and surface wettability were tuned thanks to the introduction of nisin. Lastly, the addition of this active agent allows for the implementation of antibacterial features, absent in the pristine PTF. When tested in ACE juice inoculated with Listeria monocytogenes, films containing 1.0 and 2.5 wt % of nisin powder (0.25 and 0.625 mg active nisin/g polymer) reduced the Listeria load below the detection limit during storage, whereas Listeria counts in the controls remained constant throughout the juice shelf life.

This study presents a polymeric drug delivery platform designed to address the limitations of conventional therapies for ocular surface and corneal disorders, such as dry eye disease (DED). Conventional treatments typically require frequent administration of eye drops, leading to poor bioavailability and patient adherence. We investigated the use of two random poly-(butylene succinate/diglycolate) copolymers, namely, P-(BS x BDG y ) at varying molar ratios (x, y) as vehicles for conjunctival drug delivery. Copolymers were synthesized and extensively characterized by their molecular structure, thermal and mechanical properties, and surface wettability. Prototype cylindrical devices (2 × 3 mm) were fabricated by microinjection molding. Lysozyme (Lys) and lactoferrin (Lf), two endogenous tear proteins with therapeutic relevance, were loaded into the polymer matrices, and their release profiles were evaluated. In vitro cytotoxicity assays confirmed the biocompatibility of the materials, supporting cell viability over 24 h. Protein release studies demonstrated a sustained release from the copolymeric matrices, with both proteins retaining structural integrity throughout the release period. These findings indicate that P-(BS50BDG50) and P-(BS20BDG80) based devices exhibit key features suitable for ocular surface drug delivery: structural adaptability, controlled release kinetics, and compatibility with biologically active macromolecules. These platforms may represent a promising tool for targeted and prolonged drug administration in ocular diseases requiring frequent and localized treatment.

ABSTRACT This work explored the industrial potential of an alternative green synthetic route to obtain 2,5‐furandicarboxylic acid (2,5‐FDCA) via a Henkel‐type disproportionation reaction developed by Thiyagarajan et al., meant to produce furan, and up to 30% of 2,4‐furandicarboxylic acid (2,4‐FDCA), a structural isomer of 2,5‐FDCA. Linear glycols were combined with FDCA isomers from the Henkel‐type reaction to synthesize three fully biobased random copolymers: 2,5‐2,4‐PTF, 2,5‐2,4‐PBF, 2,5‐2,4‐PHF. These copolymers were compression molded and subjected to NMR, viscometry, WAXS, DSC, and TGA analyses. Evidence suggested the formation of a partially ordered phase in 2,5‐2,4‐PHF. Mechanical and gas barrier properties of the synthesized copolymers were remarkably superior to the ones of both the reference homopolymers, with increased toughness, elongation at break and resistance to humidity. Interestingly, humidity improved the gas barrier performance of 2,5‐2,4‐PBF, making it impermeable to CO2. These findings highlighted the potential of these furan‐based copolyesters for the production of mono‐material, potentially recyclable, and sustainable food packaging. These achievements represented promising proof of concept for an integrated biorefinery and polymerization process, designed to: 1) Completely avoid the use of solvents; 2) Start from second‐generation biomass; 3) Have high carbon efficiency and few purification steps.

Fabrication of small-diameter vascular grafts remains a major clinical challenge due to thrombosis and poor long-term patency of existing synthetic materials. In this study, a family of aromatic homo- and copolyesters based on poly(butylene 2,5-furanoate) (PBF) and poly(butylene isophthalate) (PBI) was processed into electrospun scaffolds for vascular tissue engineering. The electrospinning process enabled the fabrication of defect-free flat and tubular scaffolds with tunable fiber morphology and alignment closely resembling native vascular architecture. Thermal analysis confirmed the preservation of the polymers' intrinsic semicrystalline structure and stability, with PBI and PBI-rich copolymers showing enhanced thermal resistance. Mechanical testing revealed elastic modulus, burst pressure, and strain at failure values comparable to those of the saphenous vein, indicating their suitability for vascular replacement. From the biological point of view, PBF scaffolds promoted endothelial cell adhesion and proliferation, favoring endothelialization, while PBI-rich materials reduced platelet adhesion and maintained normal coagulation parameters, highlighting their favorable intrinsic hemocompatibility. Overall, these aromatic polyesters combine mechanical robustness, endothelial compatibility, and antithrombotic behavior, demonstrating strong potential as next-generation biobased materials for small-diameter vascular grafts.

This work describes the design and characterization of nanocomposites based on multi-walled carbon nanotubes (MWCNTs) and commercial polymer matrices for innovative electronic applications. This work addresses the need for advanced materials for flexible electronics, sensing, and electromagnetic shielding. Sipolprene® 25170-W, a flexible and durable polyester-polyether block copolymer, was used as the matrix. For filler incorporation, the commercial masterbatch Plasticyl™ PBT-1501 (15 wt% of MWCNTs in PBT, polybutylene terephthalate) was employed, ensuring operational safety and ease of dispersion. The samples were produced as films (with masterbatch contents ranging from 10% to 30% corresponding to a MWCNT content ranging from 1.5 wt% to 4.5 wt%) via twin-screw extrusion with a flat die. Characterization included SEM, FT-IR, TGA, DSC, tensile testing, surface wettability, volume resistivity measurements, and electro-mechanical tests. All the results confirmed good dispersion of the filler within the matrix: from a mechanical point of view, the addition of MWCNTs increased the Young's modulus from 25 MPa of the neat material to 122 MPa of the material containing 4.5 wt% of MWCNTs, enhancing stiffness while maintaining good film handleability. Thermal analysis revealed the high stability of the obtained system and allowed us to identify the appropriate processing temperature parameters to guarantee the thermal stability of the materials during processing. Finally, electrical tests demonstrated a significant reduction in volume resistivity with increasing filler content: the volume resistivity decreased by about eleven orders of magnitude, from approximately 108 Ohm × cm of the unmodified material to 10-3 Ohm × cm for the material containing 4.5 wt% of MWCNTs. the sample with 30% of filler exhibited the typical behavior of a conductive material, and it was demonstrated that it could be used as an in situ strain sensor. All these findings confirm the potential of the developed materials for advanced technological applications.

Nowadays, interventions in ophthalmic surgery, in particular corneal ones, are countless. Regardless of the type, the success of each intervention is largely due to the correct positioning and tightness of the suture. The achievement of these goals is particularly challenging, although extensive research has been carried out to design new materials with suitable features, including shape memory ones. Among all synthetic polymers, aliphatic polyesters are credible solutions for the realization of biocompatible sutures, as they are easy to process and show a very high degree of customization. Accordingly, in the present study, poly(butylene succinate) (PBS), a biocompatible and biodegradable aliphatic polyester, was chosen as the reference homopolymer. In order to lower its high rigidity and improve the low degradation rate, it was physically and chemically mixed with poly(hexamethylene diglycolate) (PHDG), another aliphatic polyester containing ether oxygens in its main chain. The new materials obtained showed intermediate properties, especially from a thermal and mechanical point of view, depending on the molecular architecture. The introduction of PHDG, in addition to not interfering with the biocompatibility of PBS, also allowed for an increase in its degradation rate. Last, but not least, the obtained materials showed qualitative shape memory features.

Films from bio-based poly(trimethylene 2,5-furandicarboxylate-co-trimethylene sebacate) (PTFcoPTSeb) random copolymers were deeply characterized from the gas permeability point of view in order to evaluate their possible use for food packaging under different conditions of temperature and humidity. From previous studies of the same authors, such films appeared very promising, showing smart gas permeability properties under standard testing conditions (23 degrees C) to oxygen (O2) and carbon dioxide (CO2), the primary gases of interest in food packaging applications. In detail, in the present paper, the influence of temperature on gas permeability was assessed at 5 degrees C, 15 degrees C, and 38 degrees C, with the lowest value mimicking refrigeration conditions and the highest value the temperature of tropical countries. Furthermore, the films were subjected to food simulant exposure, specifically 10% v/v ethanol (to mimic fatty foods) and 3% w/v acetic acid (to represent aqueous foods). Last but not least, to evaluate the impact of humidity, the samples were conditioned in two distinct relative humidity (RH) environments: a temperate climate (23 degrees C, 85% RH, using saturated KCl) and a tropical climate (38 degrees C, 90% RH, using saturated KNO3). The films after contact with food simulants were analyzed with respect to gas permeability performance, thermal behavior, mechanical properties, and optical characteristics (including color and transparency). Comparative analysis with untreated films revealed a strong correlation between the copolymer composition, treatment conditions, and resultant performance. While each treatment exhibited a distinct influence depending on the chemical structure of the material, all copolymers demonstrated excellent permeability properties against O2 and CO2. Among the investigated materials, the copolymer containing 15 mol% PTSeb exhibited the most balanced performance under dry conditions, while showing limitations under high humidity conditions. Thermal analysis confirmed the chemical stability of the copolymer films post-treatment, and mechanical testing indicated the preservation of their structural integrity. The films remained transparent, exhibiting a slight yellowing, which intensified marginally according to the various treatments.

In order to envisage new solutions for complications associated with cardiovascular diseases, including the occlusion of small vessels, a family of random copolymers of poly(butylene trans-1,4-ciclohexanedicarboxylate) (PBCE), containing Pripol moiety, namely, poly(butylene trans-1,4-ciclohexaendicarboxylate/Pripol), were successfully synthesized. The copolymers display reduced crystallinity and stiffness compared with PBCE, exhibiting elastic modulus values that are comparable to those of materials previously investigated for similar applications. The stability of the materials under physiological conditions was demonstrated over an extended time. Cytotoxicity was confirmed by a direct contact assay with human umbilical vein endothelial cells (HUVECs), and blood compatibility was established by the absence of any change in the values of activated prothrombin time and activated partial thromboplastin time, in addition to the low adhesion of blood components. The results demonstrated that the ad hoc design is pivotal in regulating solid state and functional properties, thereby facilitating the development of innovative materials for vascular tissue engineering.

Cardiovascular diseases are responsible for a large number of severe disability cases and deaths worldwide. Strong research in this field has been extensively carried out, in particular for the associated complications, such as the occlusion of small-diameter (<6 mm) vessels. Accordingly, in the present research, two random copolyesters of poly(butylene 2,5-furandicarboxylate) (PBF) and poly(butylene isophthalate) (PBI), were successfully synthesized via two-step melt polycondensation and were thoroughly characterized from molecular, thermal, and mechanical perspectives. The copolymeric films displayed a peculiar thermal behavior, being easily processable in the form of films, although amorphous, with Tg close to room temperature. Their thermal stability was high in all cases, and from the mechanical point of view, the materials exhibited a high ultimate strength, together with values of elastic moduli tunable with the chemical composition. The long-term stability of these materials under physiological conditions was also demonstrated. Cytotoxicity was assessed using a direct contact assay with human umbilical vein endothelial cells (HUVECs). In addition, hemocompatibility was tested by evaluating the adhesion of blood components (such as the adsorption of human platelets and fibrinogen). As a result, a proper chemical design and, in turn, both the solid-state and functional properties, are pivotal in regulating cell behavior and opening new frontiers in the tissue engineering of soft tissues, including vascular tissues.

Here, 100% bio-based aliphatic/aromatic copolyesters of 2,5-furandicarboxylic acid (FDCA) were synthesized via two-stage melt polycondensation combining different ratios of FDCA and suberic acid with 1,3-propanediol. The prepared copolymers were characterized from the molecular point of view and processed into free-standing thin films. Afterward, the films were subjected to structural and thermal characterization. The mechanical response and barrier properties to O2 and CO2 were evaluated. PALS measurements were also performed to estimate free volume fraction in the samples. Then composting experiments at lab scale were carried out. The results indicated that the tuning of aliphatic co-unit content is an effective tool to modulate the chain mobility and, in turn, the kind and fraction of ordered phases developed in the samples. In addition to the usual amorphous and 3D crystalline phase, a further phase, characterized by a lower degree of order than the crystalline one, is present, whose amount is strictly related to copolymer composition. The relative fraction of all these phases is responsible for the different mechanical and barrier performances and biodegradation kinetics. Last but not least, a comparison between the copolymers under study and poly(trimethylene furanoate/sebacate) copolyesters previously investigated by the Authors was carried out.

Aims/Purpose: The treatment of ocular surface diseases (OSD) requires the administration of therapeutic agents in sufficient quantities for the proper time to reach therapeutic efficacy and relieve from subjective symptoms. Delivery systems avoid systemic routes which may require undesirable concentrations of the agents to reach appropriate levels at the target site. The aim of this work was to standardize two polyester‐based co‐polymers for ophthalmic application.Methods: The cytotoxicity, the morphological changes, and the adhesion behaviour of the copolymers in study were assessed by Human Conjunctival Fibroblasts (HConF) and Epithelial (HCjECs) cell‐culture‐based tests (ISO 10993.5). The controlled release of two model proteins presents in tear fluid, (Human Lactoferrin–LF, and Lysozyme C‐LYS‐C, Sigma) was estimated by uploading both proteins for 24h in a solution with a physiological concentration, and the released kinetic was monitored over time with the Bioanalyzer 2100 (Agilent). The structure of the proteins was monitored by circular dichroism analysis on pure and released proteins.Results: Both copolymers were demonstrated to be non‐cytotoxic, cell viability was preserved after the contact with both materials or their extracts, growth and proliferation of HConF and HCjECs on the wells were also supported, cells failed to adhere to both materials. The release analysis showed a gradual time dependance, reaching a plateau at 180 minutes for LF and 75 min for LYS‐C. The native structures of released LF and LYS were unchanged as compared to their pre‐loaded structure.Conclusions: Data from this study suggest that the copolymers under study might represent a versatile, safe and effective treatment option for chronic OSD, to ensure patient's compliance, and effective treatment.

New biobased aliphatic-aromatic flexible copolymers based on 2,5-furandicarboxylic acid, 1,3-propanediol and long aliphatic dicarboxylic acid (dodecanedioic acid) were synthesized by melt polycondensation. The structure of poly(trimethylene 2,5-furanoate-co-trimethylene dodecanedioate) (PTFcoDod), as well as their thermal, mechanical and barrier properties were examined. Selected copolymers were also tested for thermally induced shape memory properties. Gas barrier tests displayed that the prepared copolymers had satisfactory barrier properties, comparable or even better than polymers like PET, PLA and PBAT. Tensile testing confirmed the excellent mechanical properties of PTFcoDod films that, depending on the composition, are characterized by either high tensile strength and stiffness or great flexibility, with an elongation at break exceeding 300 %. Last, lab-scale degradation tests in compost showed that the PTFcoDod copolymers were biodegradable, with a rate in line with their composition. The obtained results are a continuation of research on bio-based random aliphatic-aromatic copolymers and indicate the wide potential of the obtained materials, especially for applications as both rigid and flexible environmentally friendly packaging.

The rapid development of ophthalmic surgery in recent years has made big steps forward, making interventions such as penetrating and lamellar keratoplasty or trabeculectomy widely practiced. However, the use of non-absorbable sutures in these procedures poses significant challenges. Indeed, unequal tension between the various stitches can lead to deformations of the cornea or lens and consequently to problems such as post-operative astigmatism or anisometropia. To overcome these problems, sutures with improved closure via a highly stretchable behaviour together with an excellent elastic return are a credible solution. Accordingly, to widen the plethora of superelastic polymeric materials, in the present study a novel solution deriving from two furan-based polyesters, poly(pentamethylene furanoate), PPeF, and poly(hexamethylene furanoate), PHF, was successfully obtained. Of note, these homopolymers are also entirely derived from sustainable sources. The two homopolymers were physically and chemically mixed to obtain copolymers with different block lengths, which were characterised from molecular, thermal, mechanical, and surface wettability points of view, showing interesting properties which were easily modulated as a function of block length. Lastly, all the materials showed good stability over time and cell viability and, for some of them, a great mechanical recovery upon deformation was also observed.

In the present study, bio-based polymeric blends have been prepared for applications in the field of sustainable food packaging, starting from two furan-based homopolymers, poly(hexamethylene 2,5-furanoate) (PHF) and poly(pentamethylene 2,5-furanoate) (PPeF). PHF and PPeF were synthesized by two-step melt polycondensation—a solvent-free synthetic strategy—and then binary physical mixtures, PHF/PPeF, with different weight compositions were prepared by dissolution in a common solvent. The blends were processed into compression-moulded films, and molecular, morphological, structural, thermal, and mechanical characterizations were subsequently carried out. Blending did not negatively affect the thermal stability of the parent homopolymers, and good compatibility between them was observed. This strategy also allowed for the modulation of the chain rigidity as well as of the crystallinity, simply by acting on the relative weight amount of the homopolymers. From a mechanical point of view, the presence of PPeF led to a reduction in stiffness and an increase in the elongation at break, obtaining materials with an elastomeric behaviour. Evaluation of the gas barrier properties confirmed that the good barrier properties of PHF were preserved by blending. Finally, lab-scale composting tests confirmed a greater weight loss of the mixtures with respect to the PHF homopolymer.

This work explores one of the numerous playgrounds offered by polyesters. A series of poly (alkylene trans-1,4-cyclohexanedicarboxylate)s were synthesized combining trans-1,4-cyclohexane dicarboxylic acid with four diols containing an increasing number of methylene groups (nCH2 = 3, 4, 5 and 6). The resulting polyesters are fully aliphatic. Their backbones contain cyclic aliphatic moieties and linear aliphatic segments in different relative contents depending on nCH2. The flexibility of these polyesters can be finely tuned (Tg decreases proportionally to the increase in nCH2), however the microstructure dramatically changes depending on whether nCH2 is an odd or an even number (odd-even effect). On one hand, the odd-numbered samples are easier to melt-quench to a fully amorphous glassy state; on the other hand, the even-numbered samples are prone to crystallization and crystallize very fast. The developed microstructure is complex because of the probable coexistence of different crystalline structures, mesophases, and molecular arrangements depending on the cis/trans isomerism of the cyclohexane moiety. Preliminary tests provided mechanical and barrier properties that could make these polyesters suitable for packaging applications. Composting tests showed that increasing nCH2 could eventually improve the biodegradation rate of these polyesters, although crystallinity remains the most influencing parameter.

Controlling the cooling rate experienced by a material during a manufacturing process is a challenge and a major issue. Industrial processing techniques are very diverse and may involve a whole range of cooling rates, which are sometimes extremely high for small and/or thin manufactured parts. For polymers, the cooling rate has consequences on both the microstructure and the time-dependent properties. The common cooling rates associated with conventional calorimetric measurements are generally limited to a few tens of degrees per minute. This work combines several calorimetric techniques (DSC, modulated-temperature DSC, stochastically-modulated DSC and Fast Scanning Calorimetry) to estimate the critical cooling rate required to melt-quench fast-crystallizing polyesters to their fully amorphous state, based on the example of a series of poly(alkylene trans-1,4-cyclohexanedicarboxylate) (PCHs) with a number of methylene groups in the main structure of the repeating unit nCH2 varying from 3 to 6. The even-numbered ones require faster cooling rates (about 3000 K s−1 for nCH2 = 4, between 500 and 1000 K s−1 for nCH2 = 6) compared to the odd-numbered ones (between 50 K min−1 and 100 K s−1 for nCH2 = 3, between 10 and 30 K min−1 for nCH2 = 5).