The use of biodegradable or biobased materials in the packaging sector represents one of the main solutions for reducing plastic pollution. Polybutylene Succinate (PBS) is among the most promising biopolymers for food packaging due to its easy processability, good thermal stability, ductility, and flexibility, which make it suitable for film production. However, it has poor barrier properties, similar to those of Polylactic Acid (PLA). Polyvinyl Alcohol (PVOH), on the other hand, is a biodegradable polymer with excellent gas, odour, and aroma barrier properties, high mechanical strength, and chemical resistance, but it is highly water-sensitive and difficult to process. Melt blending may offer a valid strategy to combine the advantages of both materials.

In this study, PBS/PVOH blends at different weight ratios (100/0, 80/20, 60/40, 40/60, 20/80, 0/100 wt%) were prepared via melt-compounding and characterized in terms of their rheological and structural properties. Subsequently, the blends were processed into blown films, which were evaluated for their mechanical, morphological, and barrier properties, as these are critical for food packaging applications. The results showed that PBS exhibited higher viscosity and more pronounced shear-thinning behavior compared to PVOH. Furthermore, incompatibility between the two polymer phases was observed. The blends demonstrated increased stiffness, evidenced by an increase in elastic modulus and a decrease in elongation at break. The incorporation of PVOH significantly improved the barrier performance of the films, with reductions in oxygen and water vapor permeability of up to 53% and 42%, respectively. These findings underscore the potential of PBS/PVOH blends as sustainable materials for food packaging applications requiring enhanced gas barrier properties.

Introduction:
Covalent adaptable networks (CANs) have recently emerged as a transformative class of polymeric materials that combine structural robustness with dynamic functionality. Unlike conventional thermosets, CANs incorporate reversible covalent linkages that enable reprocessability, repairability, and recyclability. In particular, the development of bio-based CANs is of significant interest, as they align with global sustainability goals while simultaneously delivering advanced performance in shape-memory and shape-shifting applications.

Methods:
In this work, we designed and synthesized bio-derived polyester-based CANs incorporating dynamic β-keto carboxylate linkages under catalyst-free conditions. The polymers were fabricated from carbohydrate- and renewable-based precursors, and their structural characteristics were confirmed using FTIR and NMR spectroscopy. Thermal and mechanical properties were evaluated through DSC, DMA, and UTM testing, while stress relaxation experiments were performed to probe the adaptability of the network under thermal stimuli.

Results:
The synthesized CANs exhibited excellent tensile strength and notable dynamic malleability, with efficient stress relaxation observed at elevated temperatures. The materials demonstrated rapid self-healing at 150 °C and could be fully reprocessed multiple times without significant loss of performance or deterioration in structural integrity.

Conclusions:
This study highlights the potential of fully bio-based CANs as multifunctional, recyclable, and programmable materials. Their combination of mechanical resilience, environmental sustainability, and advanced responsive behaviors provides a highly promising platform for next-generation polymer systems, including applications in self-healing coatings, recyclable plastics, smart functional devices, and sustainable material technologies.

The growing demand for eco-friendly packaging solutions has intensified due to increasing environmental concerns and stringent regulatory measures. Biodegradable polymers have emerged as a promising alternative to traditional plastics, offering a sustainable solution that decomposes into benign byproducts and reduces ecological harm. Recent advancements in biodegradable polymers for packaging applications have demonstrated significant potential, particularly with biopolymers such as polylactic acid (PLA), polyhydroxyalkanoates (PHAs), and starch-based composites. These biopolymers have been investigated for their potential to enhance performance and sustainability through advanced strategies, including nanomaterial reinforcement, multilayer composite structures, and biodegradable polymer blending. This study reveals that biodegradable polymers can significantly reduce environmental impact, with life cycle assessments indicating potential reductions in carbon footprint and plastic waste. The adoption of biodegradable polymers can minimize the environmental footprint associated with traditional plastics, contributing to a more sustainable packaging industry. Furthermore, the potential for recycling these polymers in a circular economy context is substantial, with mechanical and chemical recycling techniques like enzymatic biocatalysis offering opportunities to optimize end-of-life scenarios. By harnessing the power of biodegradable and recyclable polymer systems, the packaging industry can reduce its environmental footprint, minimize waste, and promote a circular economy. This approach aligns with global sustainability goals, supporting a more sustainable future for the packaging industry. The development and implementation of biodegradable polymers can pave the way for significant strides towards sustainable development, enabling the industry to reduce its reliance on fossil-based plastics and mitigate its environmental impact. With continued innovation and investment, biodegradable polymers can play a vital role in shaping a more sustainable packaging industry.

The growing concerns about the extensive use of polymers and their environmental impact have driven research into developing renewable resource-based alternatives, such as those derived from furan building blocks. Beyond the biobased origin of monomers, adopting more ecofriendly polymer synthesis strategies is critical for addressing green chemistry principles. Ring-Opening Polymerization (ROP) of cyclic esters emerges as a greener approach, offering advantages such as atom economy and milder reaction conditions compared to conventional bulk polyesterification approach [1]. In this study, the synergy between ROP as a green synthesis pathway and the biobased furanic building blocks was explored. Specifically, furanic macrocycles, macrocyclic hexamethylene 2,5-furandicarboxylate (CHF), were obtained through cyclodepolymerization of the corresponding low-molecular-weight linear polyester species under high-dilution conditions. The ROP of these macrocycles was systematically investigated under various reaction conditions to produce high-molecular-weight polyesters which were characterized in-depth by 1H-NMR, FTIR, viscosimetry, XRD, DSC, ATG and DMTA methods. As part of the end-of-life strategy of these polymers, they were subjected to cyclodepolymerization under high-dilution conditions to regenerate the original macrocycles. This approach demonstrates a potential pathway for polymer recyclability, aligning with the principles of sustainability and circular economy. The regenerated macrocycles were then characterized to confirm their structural integrity and suitability for reuse in further repolymerization processes.

Introduction:

The crossover time (tc) between the storage modulus (G′) and loss modulus (G″) is a key rheological parameter used to characterize the sol–gel transition in hydrogel systems. This metric provides valuable insight into gelation kinetics and is directly associated with the processability of polymeric materials. In this study, bio-based hydrogels were prepared from chitosan (Ch), a natural polysaccharide, and crosslinked with two different agents: glutaraldehyde (GA), a synthetic dialdehyde, and genipin (GNP), a natural crosslinker derived from Gardenia jasminoides.

Methods:

Hydrogels were prepared by dissolving 4%w/v Ch in 2%v/v acetic acid, and then mixing in a 4:1 ratio with aqueous solutions containing GA or GNP at concentrations of 1, 5, and 10% relative to Ch weight. Rheological oscillatory measurements were performed during the crosslinking reaction.

Results:

Time sweep rheological tests were used to determine tc, which marks the transition from a liquid-like to a solid-like state. At the lowest concentration (1%w/w), GA was insufficient to induce gelation, whereas GNP at the same concentration produced a tc of 269 min. At 5%w/w, both crosslinkers successfully formed solid-like gels with tc values of 18.6 min for GA and 91.2 min for GNP. Increasing the crosslinker concentration to 10% w/w further decreased tc to 4.2 min for GA and 57.6 min for GNP. As expected, higher crosslinker concentrations led to faster gelation (lower tc values). These results show that GA promotes faster crosslinking but requires higher concentrations, while GNP enables gel formation at lower dosages but with slower kinetics.

Conclusion:

Both the chemical nature and concentration of the crosslinker significantly affect the gelation time and mechanical evolution of bio-based chitosan hydrogels. Moreover, genipin represents a suitable substitute for glutaraldehyde in the development of aldehyde-free hydrogels, allowing longer processing times.

The encapsulation of phenolic compounds is a promising strategy to improve the stability and bioactivity of plant-based extracts for application in functional foods. This study aimed to encapsulate bioactive compounds extracted from Moringa oleifera leaves using gum arabic (GA) and maltodextrin (MDX), both food-grade carriers, via freeze-drying technique. These biopolymers were selected due to their non-toxic nature, emulsifying properties, and thermal resistance. The encapsulation performance was evaluated in terms of process yield, encapsulation efficiency, total phenolic compounds (TPC) and total flavonoid content (TFC), antioxidant activity, and physicochemical characteristics such as microscopical, FTIR and thermal analysis. The freeze-drying process resulted in a high yield (83 ± 3%) and encapsulation efficiency for TPC (78 ± 2%). The resulting microcapsules exhibited fine particle size (D₅₀ = 1.6 ± 0.1 µm). TPC and TFC were 21 ± 4 GAE mg/g and 12 ± 2 CE mg/g (dry basis), respectively. Antioxidant activity, assessed through DPPH and ABTS assays, showed IC₅₀ values of 171 ± 9 µg/mL and 102 ± 5 µg/mL, respectively, indicating strong radical scavenging potential. Microscopic analysis revealed irregular but compact particle morphology. FTIR spectra confirmed the presence of phenolic compounds, with characteristic O–H and C=O stretching bands, as well as evidence of hydrogen bonding interactions between the core and wall materials. Thermogravimetric analysis demonstrated good thermal stability, with major decomposition events above 220°C and structural integrity maintained below 180°C. In conclusion, freeze-drying with GA and MDX proved effective in preserving the chemical and thermal stability of M. oleifera leaf phenolics, supporting their potential use in thermosensitive functional food formulations.

The reuse of soybean oil reduces environmental impacts, prevents sewage system clogging, promotes sustainability, and adds value to a waste material. In this study, post-consumer epoxidized soybean oil (RESO) was cured with fumaric acid to develop green composites reinforced with sugarcane bagasse (F). The natural reinforcement underwent chemical modification to improve its interaction with RESO, aiming to evaluate impact strength, tensile strength, Shore D hardness, and contact angle. Additionally, scanning electron microscopy (SEM) was used to analyze the interfacial interaction between the RESO matrix and the sugarcane bagasse before (F) and after treatment (TF). The RESO/F composites with 10 and 20 parts per hundred resin (phr) did not exhibit a reinforcement effect; they acted only as traditional fillers, improving only the elastic modulus and Shore D hardness compared to pure RESO. In contrast, the treatment of sugarcane bagasse contributed to the production of RESO/TF composites with improved mechanical performance. The RESO/TF (20 phr) formulation showed increases of 230.7% in elastic modulus, 64.2% in tensile strength, and 114.7% in Shore D hardness compared to pure RESO, suggesting a reinforcement filler effect. SEM analysis revealed that the RESO/TF (20 phr) composite exhibited improved interfacial interaction between the phases, which enhanced stress transfer as observed in the mechanical tests. The contact angle of approximately 95.4° and the impact resistance of 38.3 J/m were similar to those of the RESO matrix, reinforcing that the chemical treatment of the sugarcane bagasse contributed to a synergistic effect on the material properties. The reuse of RESO for composite production aligns with circular economy principles and sustainability.

The growing impact of fossil‑based plastics on the environment has driven interest in bioplastics such as polylactic acid (PLA), a biobased and compostable polyester widely used in food packaging but with limited properties. Although designed for composting, preventing the contamination of traditional recycling streams is essential¹. In industrial production, defective parts and burrs discarded can be reprocessed into pellets from a controlled source, avoiding complex washing². Studies have evaluated performance after reprocessing cycles³; however, for food contact applications, the potential migration of substances, including non‑intentionally added substances, remains a challenge.

This study evaluates the reuse of industrial discarded PLA parts for food contact. Films were produced from virgin and reprocessed PLA through melt extrusion and hot pressing, with reprocessing simulated by one additional extrusion cycle to the virgin material. Melt flow index (MFI), tensile properties, overall migration (ethanol 50 % v/v, 10  days, 40 °C), and water vapor transmission rate (WVTR) were assessed. Volatile (VOCs), semi‑volatile (SVOCs) and non‑volatile (NVOCs) compounds were identified through chromatographic/mass‑spectrometric techniques. The migration of metals (Ba, Co, Mn, Zn, Cu, Fe, Li, Al, Ni, Eu, Gd, La, Tb, As, Cd, Cr, Pb, Hg, Sb) was tested in 3 % acetic acid (60 °C, 10  days).

Results showed a slight rise in MFI, indicating minimal degradation. Tensile strength and modulus decreased slightly but not significantly. WVTR remained comparable. Overall and metal migration increased marginally but stayed well below the legal limits. The reprocessed PLA exhibited more VOCs and NVOCs absent in the virgin sample. Aldehydes and oligomers predominated, though most showed low migration, underscoring the importance of clean equipment. Metal migration stayed below specific limits. Overall, the reprocessed PLA retained functional properties and kept the migration of key substances within established limits.

1. Regulation (EU) 2025/40.
2. Silva, T. et al. J. Polym. Sci. 63, 2043–2054 (2025).
3. Agüero, Á. et al. Polymers. 15, 285 (2023).

Introduction.

The separation of propene/propane is among the most energy-intensive industrial processes because of the massive scale and the high energy demanded by the traditional cryogenic distillation method [1]. In this work, we report the preparation of MMMs consisting of cellulose acetate, 30% wt. [BMIM]⁺[Tf₂N]^‑, and 20% wt. of a series of ZIFs (ZIF-8, ZIF-67, and ZIF-8-67). The aim is to surpass the current state-of-the-art by incorporating bimetallic ZIF-8-67, supported by an ionic liquid as both a compatibiliser and a promoter of permeability.

Experimental/methodology.

Thin film composites were fabricated by spin-coating on PAN support. X-Ray diffraction, FT-IR, and SEM were performed. Single-gas and mixed-gas permeation measurements were applied [2].

Results and discussion.

The addition of 30%[BMIM]⁺[Tf₂N]^‑, by showing the trade-off behaviour, led to an increase in Propene permeability, compared to the neat CA membrane. The contribution of a series of ZIFs in ZIF/IL-CA MMMs increased the C₃H₆/C₃H₈ selectivity as well as the C₃H₆ permeability, with ZIF-8-67 outperforming its parent ZIFs. C₃H₆/C₃H₈ Mixed-gas measurements confirmed a selective performance of ZIF-8-67/IL-CA MMM.

Conclusion

Overall, this study highlights the significant role of bimetallic ZIF-8-67 in enhancing gas separation performance when incorporated into IL-CA membranes. The synergistic properties of Zn²⁺ and Co²⁺ in ZIF-8-67, combined with the role of [BMIM]⁺[Tf₂N]^- in addressing interfacial inconsistency, contributed to its superior gas transport properties and selectivity.

[1] A.C.C. Campos, et al., Ind. Eng. Chem. Res. 2018, 57, 10071–10085.

[2] S. C. Fraga, et al., J. Membr. Sci. 2018, 561, 39.

In vascular surgery, polymer materials, both natural and synthetic, are widely used for grafting, stenting, and tissue engineering. In this review, we focus on evaluating materials science and engineering, including biocompatibility and clinical outcomes, to aid in biomedical decisions and material selection.
Following the PRISMA guidelines, we searched PubMed, ScienceDirect, Scopus, and the Persian databases Magiran and SID from 2000 to 2024. Inclusion criteria were the use of the specific terms “natural polymers” and “synthetic polymers” alongside “vascular surgery” and “biomechanical properties” and experimental and clinical studies with quantitative biomechanical data. We performed a qualitative assessment of all included studies.
From 2847 articles, 156 studies were selected, which included 89 experimental studies, 45 clinical trials, and 22 reviews. Natural polymers such as collagen and chitosan had better biocompatibility compared to that of synthetic polymers (92.3% vs 78.1%, p<0.001), although they had lower mechanical strength (28.9±6.3 vs 45.2±8.7 MPa, p<0.001). In comparison, synthetic polymers had high tensile strength, with PET at 72.4±12.1 MPa and PU showing 650-800% elongation. Clinically, natural polymers led to better 5-year success rates in natural coronary grafts (85.3% vs 78.9%), while synthetic polymers outperformed in peripheral grafts (89.2% vs 76.4% at 3 years). Natural polymers caused decreased inflammatory responses (8.7% vs 15.2%) but higher rates of complications due to degradation (12.4% vs 3.8%).
Synthetic polymers had higher mechanical strength, while natural polymers had better soft tissue integration and biocompatibility. There is additional flexibility in the design with hybrid systems. Further studies of clinical outcomes are needed with smart polymers and uniform methods of testing.