Polymers

19 pages, 5545 KB

Open AccessEditor’s ChoiceArticle

Novel NTA-Ni²⁺ Agarose-Based Microspheres: Structural Features and Chromatographic Capacity

by Min Zhao, Chen Liang, Boheng Liu, Ahsan Javed, Ran Zhou, Xiaozhen Diao, Chuanyun Ren and Wenhui Wu

Polymers 2026, 18(5), 566; https://doi.org/10.3390/polym18050566 - 26 Feb 2026

Viewed by 235

Abstract

The design and optimization of immobilized metal affinity chromatography (IMAC) media are crucial to enhancing the purification efficiency of recombinant proteins. In this study, the agarose-based microspheres are prepared by using a three-factorial Box–Behnken design followed by NTA-Ni²⁺ agarose-based microspheres (ABM) preparation [...] Read more.

The design and optimization of immobilized metal affinity chromatography (IMAC) media are crucial to enhancing the purification efficiency of recombinant proteins. In this study, the agarose-based microspheres are prepared by using a three-factorial Box–Behnken design followed by NTA-Ni²⁺ agarose-based microspheres (ABM) preparation by the “one-step” crosslinking of epichlorohydrin (ECH)–nitrilotriacetic acid (NTA) to efficiently couple the NTA ligand to the surface of the matrix. After preparation, various sophisticated techniques, including SEM, AFM, DSC, FTIR, and SDS-PAGE, were used to analyze the morphological structure, thermal stability, and chemical composition of NTA-Ni²⁺ ABM. The optimal conditions are identified as an emulsifier PP concentration of 8.12 wt%, a stirring speed of 1624.46 rpm, and an oil-phase temperature of 53.86 °C, giving a span value (Y) of 0.50684. SEM, AFM, DSC, and FTIR results showed that the fabricated NTA-Ni²⁺ ABM were structurally stable and had a uniform cross-linking network for up to 8 h of coupling reaction time. The performance results showed that the beads had a high binding capacity for His-tagged proteins (15.2 ± 0.8 mg/mL), and SDS-PAGE results demonstrated the efficient purification ability for target proteins. These findings provide the theoretical basis and a practical solution for the rational design and application of IMAC medium. Full article

(This article belongs to the Section Biobased and Biodegradable Polymers)

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15 pages, 1414 KB

Open AccessEditor’s ChoiceArticle

Graphoepitaxial Control of Lamellar Block Copolymer Alignment in Wide Trenches: Effects of Trench Width and Sidewall Tilt

by June Huh

Polymers 2026, 18(5), 557; https://doi.org/10.3390/polym18050557 - 25 Feb 2026

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Abstract

Graphoepitaxy provides a robust route to align lamellar block copolymers in topographic trenches, yet alignment often degrades rapidly as the trench width increases into the wide-trench regime. Here, mesoscale density functional simulations under thermal annealing are used to quantify width- and geometry-dependent ordering [...] Read more.

Graphoepitaxy provides a robust route to align lamellar block copolymers in topographic trenches, yet alignment often degrades rapidly as the trench width increases into the wide-trench regime. Here, mesoscale density functional simulations under thermal annealing are used to quantify width- and geometry-dependent ordering of symmetric lamella-forming block copolymers confined in trenches. A Fourier-based alignment metric reveals a sharp, sigmoidal decay of alignment with trench width normalized by the natural lamellar period, indicating a crossover between (i) a globally aligned state established by wall-guided propagation and (ii) a misoriented, kinetically trapped state produced by bulk-like interior nucleation followed by domain impingement. This width dependence is well captured by a logistic form, yielding a characteristic crossover width and transition sharpness that compactly describe the accessible alignment window. Parameter sweeps show that increasing incompatibility shifts the crossover to smaller widths, whereas stronger sidewall surface fields extend the accessible width range with diminishing returns at large fields; in the range examined, film thickness has little influence on the crossover. Finally, simulations in trapezoidal trenches demonstrate that high alignment persists for moderate sidewall taper, while larger taper promotes lamellar bending and defects. A geometric criterion based on the variation in trench width across the film thickness, using a numerical threshold derived from strong-segregation theory, rationalizes the observed onset of degradation when this variation approaches approximately 1.4 lamellar periods. These results provide a mechanistic framework and quantitative guidelines for extending graphoepitaxial lamellar alignment beyond the narrow-confinement regime. Full article

(This article belongs to the Special Issue New Advances in Theory and Simulation of Block Copolymers)

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31 pages, 2314 KB

Open AccessEditor’s ChoiceReview

Recent Trends in the Chemical Modification of Polysaccharides for Food Packaging: A Review

by Paramabhorn Tosuwan, Hannah S. Leese and Christopher J. Chuck

Polymers 2026, 18(4), 529; https://doi.org/10.3390/polym18040529 - 21 Feb 2026

Viewed by 337

Abstract

The environmental impact of petroplastics that do not readily biodegrade has intensified the search for sustainable packaging materials. Polysaccharides derived from plant and marine sources are biodegradable and renewable, but their hydrophilicity and weak mechanical and barrier properties limit their use in high-performance [...] Read more.

The environmental impact of petroplastics that do not readily biodegrade has intensified the search for sustainable packaging materials. Polysaccharides derived from plant and marine sources are biodegradable and renewable, but their hydrophilicity and weak mechanical and barrier properties limit their use in high-performance packaging. Chemical modification offers an effective solution by introducing hydrophobic or functional groups that enhance physicochemical performance, making modified polysaccharides strong candidates for sustainable packaging applications. This review provides a comprehensive overview of recent advances in the chemical modification and development of plant-based polysaccharides (starch, cellulose and its derivatives, and pectin) and marine-based polysaccharides (agar, carrageenan, alginate, and chitosan) for food packaging applications. Emphasis on how chemical modifications influence key functional properties relevant to sustainable packaging, including barrier performance, biological activities, and freshness-monitoring capabilities. Film fabrication techniques such as solution casting, extrusion, coating, and electrospraying are also discussed regarding their impact on material performance. Overall, the reviewed studies demonstrate that chemical modification can substantially enhance the functional properties of polysaccharides and enable active and intelligent packaging functionalities. While challenges related to food safety, scalable production, environmental impact, and real-world performance remain, chemically modified polysaccharides show strong potential as sustainable and functional materials for the next generation of food packaging. Full article

(This article belongs to the Special Issue Modification of Natural Biodegradable Polymers)

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13 pages, 3254 KB

Open AccessEditor’s ChoiceArticle

Surface-Treated MDI-Compatibilized PPC-P/PPC-ECH Film with PVA/Tannic Acid Complex for High-Gas-Barrier Application

by Shuangshuang Yue, Jiangtao Deng, Guoshan He, Wanjuan Wang, Min Xiao, Sheng Huang, Shuanjin Wang, Dongmei Han and Yuezhong Meng

Polymers 2026, 18(4), 520; https://doi.org/10.3390/polym18040520 - 20 Feb 2026

Viewed by 329

Abstract

A novel low-cost poly(propylene carbonate-co-epichlorohydrin) (PPC-ECH) with mechanical properties similar to those of poly (butylene adipate-co-terephthalate) (PBAT) was developed and incorporated into a poly(propylene carbonate-co-phthalate) (PPC-P) matrix. Meanwhile, 4, 4′-diphenylmethane diisocyanate (MDI) was employed as a reactive compatibilizer and mixed with PPC-P and [...] Read more.

A novel low-cost poly(propylene carbonate-co-epichlorohydrin) (PPC-ECH) with mechanical properties similar to those of poly (butylene adipate-co-terephthalate) (PBAT) was developed and incorporated into a poly(propylene carbonate-co-phthalate) (PPC-P) matrix. Meanwhile, 4, 4′-diphenylmethane diisocyanate (MDI) was employed as a reactive compatibilizer and mixed with PPC-P and PPC-ECH to create a variety of PPC-P/PPC-ECH/MDI blends. The effects of PPC-ECH and MDI content on the mechanical, optical, thermal, morphological, and gas barrier properties of the blends were systematically investigated. Results demonstrated that MDI reacts with both PPC-P and PPC-ECH, forming a chemically bonded interface that significantly improves their compatibility. Notably, when 2 phr of MDI was incorporated, the elongation at break of the PPC-P/PPC-ECH/2MDI blend increased dramatically from 71% to 502%, while maintaining good tensile strength (~23 MPa) and light transmittance (~80%). To further enhance the gas barrier performance, a high-oxygen-barrier poly(vinyl alcohol) (PVA)/tannic acid (TA) complex coating was applied to the surface of the PPC-P/PPC-ECH/2MDI film. This coating synergistically leveraged the abundant hydroxyl groups in PVA and TA to form a dense hydrogen-bonded network, reducing oxygen permeability to an ultra-low value of 0.1 cm³·mm/(m²·day). This outstanding performance highlights the strong potential of PPC-P/PPC-ECH-based films for advanced packaging applications. Full article

(This article belongs to the Section Biobased and Biodegradable Polymers)

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16 pages, 10128 KB

Open AccessEditor’s ChoiceArticle

Spatial Tribological Properties of PI/PTFE Based Self-Stratifying Composite Coatings Grafted by Amino-POSS

by Chuanyong Yu, Min Wei, Qiwei Wang and Wei Zhang

Polymers 2026, 18(4), 521; https://doi.org/10.3390/polym18040521 - 20 Feb 2026

Viewed by 301

Abstract

In low Earth orbit (LEO), special environments such as atomic oxygen (AO), alternating high and low temperatures, and high vacuum can seriously affect the reliability and service lifetime of moving parts of space equipment. Therefore, there is an increasingly urgent demand for long-life, [...] Read more.

In low Earth orbit (LEO), special environments such as atomic oxygen (AO), alternating high and low temperatures, and high vacuum can seriously affect the reliability and service lifetime of moving parts of space equipment. Therefore, there is an increasingly urgent demand for long-life, high-performance lubricating protective coatings with the rapid evolution of astronautical technology. In this study, polyimide (PI) was modified by polyhedral oligomeric silsesquioxane (POSS) with different numbers of functional groups to fabricate PI-based self-stratifying gradient composite lubricating coatings. The coating exhibited significantly enhanced AO resistance, and its vacuum tribological properties under alternating high and low temperature conditions were investigated. Results show that the mass loss of the gradient coating under AO exposure was significantly reduced by 78%, and the tribological properties of the coating under high and low temperature alternating conditions were significantly different. The friction coefficient was more stable and was smaller than that at high temperatures, and the wear rates of the POSS-modified coating also decreased by 77.5% and 50% for both high and low temperatures compared with that of the PI/PTFE coating. Full article

(This article belongs to the Special Issue Polymers for Protective Coatings)

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21 pages, 3905 KB

Open AccessEditor’s ChoiceReview

Molecular Doping Mechanisms and Rational Molecular Design Strategies for High Doping Efficiency

by Hyojin Kye, Min Seon Kim and Bong-Gi Kim

Polymers 2026, 18(4), 501; https://doi.org/10.3390/polym18040501 - 17 Feb 2026

Viewed by 334

Abstract

This review provides a comprehensive overview of molecular doping in organic semiconductors (OSCs), with particular emphasis on the mechanistic understanding of doping processes, rational material design strategies, and processing approaches for achieving high doping efficiency and stability. We discuss fundamental doping mechanisms, including [...] Read more.

This review provides a comprehensive overview of molecular doping in organic semiconductors (OSCs), with particular emphasis on the mechanistic understanding of doping processes, rational material design strategies, and processing approaches for achieving high doping efficiency and stability. We discuss fundamental doping mechanisms, including integer charge transfer and orbital hybridization models, and highlight how molecular structure, polymer design, and dopant–host interactions influence electrical performance. Recent advances in processing strategies—such as sequential, vapor-phase, and hybrid doping methods—are also summarized in relation to microstructural control and charge transport optimization. In addition, the implications of molecular doping for emerging organic thermoelectric applications are addressed, emphasizing the interplay between dopant distribution, morphology, and device performance. By integrating mechanistic insights, material design principles, and application perspectives, this review aims to provide a unified framework for researchers in organic electronics, materials science, and thermoelectric device engineering seeking to develop highly efficient and stable molecularly doped organic conductors. Full article

(This article belongs to the Special Issue Advanced Polymers for Harnessing Power and Energy)

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16 pages, 2643 KB

Open AccessEditor’s ChoiceArticle

Hydrophobic Fibers with Hydrophilic Domains for Enhanced Fog Water Harvesting

by Joanna Knapczyk-Korczak, Katarzyna Marszalik, Marcin Gajek and Urszula Stachewicz

Polymers 2026, 18(3), 425; https://doi.org/10.3390/polym18030425 - 6 Feb 2026

Viewed by 431

Abstract

Fog water collectors (FWCs) present a sustainable solution for arid regions where fog is a primary water source. To improve their efficiency, we developed a durable and high-performance mesh composed of electrospun hydrophobic thermoplastic polyurethane (TPU) fibers combined with hydrophilic cellulose acetate (CA) [...] Read more.

Fog water collectors (FWCs) present a sustainable solution for arid regions where fog is a primary water source. To improve their efficiency, we developed a durable and high-performance mesh composed of electrospun hydrophobic thermoplastic polyurethane (TPU) fibers combined with hydrophilic cellulose acetate (CA) microbeads. This hybrid design represents a novel biomimetic strategy, mimicking natural fog-harvesting mechanisms by optimizing wetting and drainage. Despite the significant reduction in average fiber diameter, the TPU-CA mesh maintained mechanical strength close to 1 MPa, comparable to pristine TPU. The introduction of hydrophilic domains into a hydrophobic fibrous network is a unique architectural approach that enhanced fog collection performance, achieving a high water harvesting rate of 127 ± 12 mg·cm⁻²·h⁻¹. Remarkably, although the mesh remained predominantly hydrophobic, droplets shed completely from its vertical surface, exhibiting near-zero contact angle hysteresis. This synergistic wetting concept enables performance unattainable with conventional single-wettability meshes. Compared to single-material meshes, the TPU-CA hybrid showed nearly double the water collection efficiency. The innovative interplay between surface chemistry, microscale heterogeneity, and mechanical robustness is key to maximizing water capture and transport, offering a promising path for scalable, efficient FWCs in poor water-stressed regions. Full article

(This article belongs to the Special Issue Synthesis, Production and Applications of Cellulose)

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16 pages, 3370 KB

Open AccessEditor’s ChoiceArticle

Numerical Investigation of Dynamic Wrinkling Behaviors in Stiff-Film/PDMS-Substrate Structure

by Haohao Bi, Wenjie Li, Liuyun Wang and Bo Wang

Polymers 2026, 18(2), 292; https://doi.org/10.3390/polym18020292 - 21 Jan 2026

Viewed by 253

Abstract

Thin film/substrate structures based on the principle of buckling mechanics exhibit both excellent stretchability and mechanical stability, and they have been recognized as a critical configuration in the design of flexible electronic devices. During application, flexible electronic devices are usually subjected to complex [...] Read more.

Thin film/substrate structures based on the principle of buckling mechanics exhibit both excellent stretchability and mechanical stability, and they have been recognized as a critical configuration in the design of flexible electronic devices. During application, flexible electronic devices are usually subjected to complex dynamic environments. Therefore, it is of great significance to investigate the dynamic behavior of thin film/substrate structures for the design of flexible electronic devices. The bending energy, membrane energy, and kinetic energy of the thin film and the elastic energy of the substrate were calculated. On this basis, the dynamic equation of the thin film/substrate structure with a checkerboard wrinkled pattern was derived by applying the principle of minimum energy combined with the Lagrangian function. Numerical simulations were conducted on the system to analyze the effect of pre-strain and the Young’s modulus of substrate on the system’s potential energy function, simulate the temporal response of the system’s dynamic behavior, and investigate the influences of pre-strain and the Young’s modulus of substrate on system stability and the chaos critical value. Theoretical support is expected to be provided for the design of two-dimensional (2D) thin film/substrate structures through this research. Full article

(This article belongs to the Special Issue Dynamic Behavior of Polymer Composite Materials and Structures, 2nd Edition)

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11 pages, 1238 KB

Open AccessEditor’s ChoiceArticle

Advanced Green Materials: Sustainable Cellulose–Lignin Composite Films Prepared via Ionic Liquid Processing

by Witold Madaj, Michał Puchalski, Konrad Sulak, Dariusz Wawro and Ewelina Pabjańczyk-Wlazło

Polymers 2026, 18(2), 211; https://doi.org/10.3390/polym18020211 - 13 Jan 2026

Viewed by 579

Abstract

The article presents the preparation method of a green composite material composed of cellulose and lignin using an ionic liquid as a solvent. In the process, cellulose and lignin are dissolved in the ionic liquid and subsequently regenerated into a composite film via [...] Read more.

The article presents the preparation method of a green composite material composed of cellulose and lignin using an ionic liquid as a solvent. In the process, cellulose and lignin are dissolved in the ionic liquid and subsequently regenerated into a composite film via coagulation in ethanol/water bath. The research focused on evaluating the mechanical properties of the resulting composite, which exhibited a high tensile strength exceeding 100 MPa, demonstrating its robustness and potential for various applications. Importantly, the simultaneous integration of lignin enabled a favorable balance between high mechanical strength and enhanced biodegradability, addressing a common trade-off in sustainable materials. Additionally, the biodegradation behavior of the composite in soil was investigated, showing that it gradually decomposes, making it environmentally friendly. Toxicity tests on soil bacteria indicated that the composite does not adversely affect microbial activity, supporting its suitability for ecological use. Furthermore, the gas permeability and water vapor transmission of the composite film was assessed, providing insight into its barrier properties. Overall, the study highlights the potential of cellulose-lignin composites produced via ionic liquids as sustainable and biodegradable materials with promising mechanical and environmental properties. Full article

(This article belongs to the Special Issue Cellulose and Its Composites: Preparation and Applications)

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21 pages, 974 KB

Open AccessEditor’s ChoiceReview

Natural Deep Eutectic Solvents for PHB Recovery: Mechanistic Insights and Implications for Sustainable Downstream Processing

by Antonio Zuorro, Roberto Lavecchia, Jefferson E. Contreras-Ropero, Janet B. García-Martínez and Andrés F. Barajas-Solano

Polymers 2026, 18(2), 169; https://doi.org/10.3390/polym18020169 - 8 Jan 2026

Viewed by 813

Abstract

The growing concern over plastic pollution and the widespread presence of micro- and nanoplastics has renewed interest in polyhydroxybutyrate (PHB) as a biodegradable alternative; however, its industrial deployment remains constrained by costly recovery operations with a high environmental burden. This study examines how [...] Read more.

The growing concern over plastic pollution and the widespread presence of micro- and nanoplastics has renewed interest in polyhydroxybutyrate (PHB) as a biodegradable alternative; however, its industrial deployment remains constrained by costly recovery operations with a high environmental burden. This study examines how PHB biosynthesis and intracellular organization, physicochemical properties, and the characteristics of the producing microorganism influence the performance of conventional recovery routes, including extraction with organic solvents, alkaline/oxidative chemical digestion, and enzymatic–physical schemes coupled with mechanical disruption. Based on this foundation, quantitative data are analyzed for PHB content in bacteria, mixed microbial cultures, cyanobacteria, and microalgae, along with extraction yields, polymer purity, and solvent recyclability in processes employing chlorine-free solvents, green solvents, and hydrophobic natural deep eutectic solvents (NaDESs) formulated with terpenes and organic acids. The analysis integrates mechanistic perspectives on NaDES–cell and NaDES–PHB interactions with solvent design criteria, biorefinery configurations, and preliminary evidence from technoeconomic and life cycle assessments. The findings identify NaDES as an up-and-coming platform capable of reconciling biopolymer quality with the principles of green chemistry while delineating critical gaps in recovery efficiency, viscosity management, solvent recycling, and pilot-scale validation. Full article

(This article belongs to the Section Biobased and Biodegradable Polymers)

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20 pages, 5622 KB

Open AccessEditor’s ChoiceArticle

Kraft Lignin-Based Polyurethane with GVL: A Sustainable Coating Alternative for Recycled Linerboard

by Julia C. Figueiredo, Roberto C. C. Lelis, Rosane N. Castro, Fernando J. B. Gomes, Ericka F. A. Redmond and Biljana M. Bujanovic

Polymers 2026, 18(1), 118; https://doi.org/10.3390/polym18010118 - 31 Dec 2025

Viewed by 492

Abstract

Food packaging is the largest segment of the global plastics market, yet its low degradability and limited performance in preserving perishable goods highlight the need for more sustainable alternatives. This study investigates the use of industrial softwood kraft lignin, a renewable polyol, and [...] Read more.

Food packaging is the largest segment of the global plastics market, yet its low degradability and limited performance in preserving perishable goods highlight the need for more sustainable alternatives. This study investigates the use of industrial softwood kraft lignin, a renewable polyol, and γ-valerolactone (GVL), an excellent green lignin solvent, to synthesize bio-based polyurethane (PU) coatings for recycled linerboard. PU was synthesized with hexamethylene diisocyanate (HDI), GVL, and 1,4-diazabicyclo[2.2.2]octane (DABCO) as a catalyst and applied to recycled linerboard (166.6 g/m²) at three coating weights: 13.5, 16.5, and 23.5 g/m². The coating enhanced water resistance, as shown by the reduced water vapor transmission rate (WVTR) and Cobb₁₈₀₀ values. Oil resistance was also significantly improved, reaching a Kit rating of 11 at the highest coating weight. Mechanical performance was maintained or enhanced, with increases in ring crush strength (RCT) and tensile index. These findings confirm the effectiveness of lignin-based PU in improving both the barrier and mechanical properties of packaging paper. Additionally, this approach presents an environmentally responsible alternative to petroleum-based coatings, adding value to lignin as a byproduct of the pulp and paper industry and supporting the transition toward more circular and sustainable packaging materials. Full article

(This article belongs to the Special Issue Lignin-Based Polymers)

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12 pages, 2410 KB

Open AccessEditor’s ChoiceArticle

Modulating Cell–Scaffold Interaction via dECM-Decorated Melt Electrowriting PCL Scaffolds

by Wenchao Li, Xiang Gao and Peng Zhang

Polymers 2025, 17(23), 3133; https://doi.org/10.3390/polym17233133 - 25 Nov 2025

Viewed by 2496

Abstract

Aligned fibrous scaffolds are essential for directing soft-tissue regeneration, yet synthetic polymers lack native biochemical cues. To bridge this gap, bioactive and anisotropic scaffolds were developed by combining melt electrowriting (MEW) with decellularized extracellular matrix (dECM) decoration to enhance cell–scaffold interactions for soft [...] Read more.

Aligned fibrous scaffolds are essential for directing soft-tissue regeneration, yet synthetic polymers lack native biochemical cues. To bridge this gap, bioactive and anisotropic scaffolds were developed by combining melt electrowriting (MEW) with decellularized extracellular matrix (dECM) decoration to enhance cell–scaffold interactions for soft tissue engineering. Porous polycaprolactone (PCL) scaffolds with aligned microfibers and tunable pore architectures (aspect ratios 1:1, 1:2, and 1:3) were fabricated via MEW and subsequently coated with porcine skeletal muscle dECM using a dip-gelation method. Comprehensive surface characterization confirmed the presence and robust adhesion of the dECM coating on the PCL scaffolds, which concurrently enhanced surface hydrophilicity. Furthermore, mechanical testing demonstrated that the resulting composite scaffold retained the structural integrity required to meet the mechanical demands of tissue regeneration. In vitro studies using L929 fibroblasts demonstrated that dECM decoration significantly improved cell adhesion, proliferation, and alignment along the fiber direction. Notably, scaffolds with 1:1 and 1:2 aspect ratios supported the highest cell density and guided morphological elongation most effectively. These findings highlight the synergistic potential of topographical cues and biochemical signaling in scaffold design for functional tissue regeneration. Full article

(This article belongs to the Special Issue Advanced Polymeric Composites in Dentistry: Synthesis, Properties and Applications)

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15 pages, 604 KB

Open AccessEditor’s ChoiceArticle

Influence of the Resin Matrix Phase on the Fatigue Resistance of Model Dental Composite Resins

by Diana Leyva del Rio and Robert R. Seghi

Polymers 2025, 17(23), 3118; https://doi.org/10.3390/polym17233118 - 24 Nov 2025

Viewed by 759

Abstract

This study aimed to assess how different resin matrix formulations affect the fatigue resistance of resin dental composites. Model dental composites were formulated using six distinct monomer mixtures: two Bis-GMA (bisphenol A-glycidyl methacrylate):TEGDMA (triethylene glycol dimethacrylate) (60:40 and 80:20 mole%), two UDMA (urethane [...] Read more.

This study aimed to assess how different resin matrix formulations affect the fatigue resistance of resin dental composites. Model dental composites were formulated using six distinct monomer mixtures: two Bis-GMA (bisphenol A-glycidyl methacrylate):TEGDMA (triethylene glycol dimethacrylate) (60:40 and 80:20 mole%), two UDMA (urethane dimethacrylate):TEGDMA (60:40 and 80:20 mole%), one Bis-GMA:UDMA:TEGDMA (35:35:30 mole%), and one Fit852:UDMA:TEGDMA (35:35:30 mole%). Cyclic fatigue resistance (CFR) of the resin composites was measured in a biaxial test mode using staircase analysis. Additional evaluations included biaxial flexural strength (BFS), degree of conversion (DC), water sorption (WS), and viscoelastic properties of the unfilled resins, such as the storage modulus (E′), loss modulus (E″), tan δ (E″/E′), and stiffness (k′). Data were subjected to one-way ANOVA with Tukey post hoc analyses. Pearson correlation and stepwise regression analyses were conducted to examine the relationships among variables. The UT6040 model composite exhibited the highest CFR (82.61 ± 8.83 MPa), significantly outperforming other formulations. Tan δ of the resin matrix showed the strongest correlation with CFR (r = 0.974), and was also shown to be the most influential predictor for the CFR of the particulate composites. The composition of the resin matrix has a significant impact on the CFR of dental composites. Among the properties evaluated, the viscoelastic parameter tan δ emerged as a strong and reliable predictor of CFR, emphasizing the importance of targeting viscoelastic behavior in the design of dental composite formulations. Full article

(This article belongs to the Section Polymer Analysis and Characterization)

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19 pages, 6379 KB

Open AccessEditor’s ChoiceArticle

Ionic Conductive Hydrogels with Choline Salt for Potential Use in Electrochemical Capacitors

by Jan Malczak, Wiktoria Żyła, Piotr Gajewski, Katarzyna Szcześniak, Łukasz Popenda and Agnieszka Marcinkowska

Polymers 2025, 17(22), 3030; https://doi.org/10.3390/polym17223030 - 14 Nov 2025

Viewed by 1190

Abstract

Choline salts represent sustainable and safe electrolyte systems. In this study, an aqueous 1 M choline nitrate solution was employed to prepare hydrogel polymer electrolytes (HPE) via in situ photopolymerization. To enhance compatibility between the electrolyte and polymer matrix, choline methacrylate was synthesized [...] Read more.

Choline salts represent sustainable and safe electrolyte systems. In this study, an aqueous 1 M choline nitrate solution was employed to prepare hydrogel polymer electrolytes (HPE) via in situ photopolymerization. To enhance compatibility between the electrolyte and polymer matrix, choline methacrylate was synthesized and used as a functional monomer alongside HEMA and PEGDA. The photocurable formulation contained 70 wt.% electrolyte and 30 wt.% monomer mixture. Subsequent electrolyte uptake increased the electrolyte fraction in the HPE to 87 wt.%. The use of choline methacrylate enabled the formation of transparent HPE with favorable mechanical performance, showing puncture resistance of 0.33 N and 0.28 N at elongations of 7.9 mm and 4.4 mm for samples with 70 and 87 wt.% electrolyte, respectively. High ionic conductivity was achieved, reaching ~18 mS/cm and ~34 mS/cm for HPE with 70 and 87 wt.% electrolyte. Finally, a capacitor assembled with HPE containing 87 wt.% electrolyte demonstrated good operational parameters, confirming the applicability of this system in energy storage devices. This work highlights the potential of choline-based electrolytes and polymerizable choline derivatives as functional components for the design of efficient, safe, and environmentally friendly gel polymer electrolytes. Full article

(This article belongs to the Special Issue Active Polymeric Materials for Electrochemical Applications)

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24 pages, 8615 KB

Open AccessEditor’s ChoiceArticle

Xylitol Modification of Electrospun Polymer Scaffolds: Impact on Physicochemical and Antibacterial Properties

by Francesco Boschetto, Matteo Zanocco, Kaeko Kamei, Huaizhong Xu and Elia Marin

Polymers 2025, 17(22), 3024; https://doi.org/10.3390/polym17223024 - 14 Nov 2025

Viewed by 1018

Abstract

Electrospun fibrous scaffolds based on cellulose acetate (CA), polycaprolactone (PCL), and poly (L-lactic acid) (PLLA) are versatile materials with applications spanning diverse fields, but in their pristine form, they typically lack significant inherent antibacterial properties. To address this limitation and expand their utility, [...] Read more.

Electrospun fibrous scaffolds based on cellulose acetate (CA), polycaprolactone (PCL), and poly (L-lactic acid) (PLLA) are versatile materials with applications spanning diverse fields, but in their pristine form, they typically lack significant inherent antibacterial properties. To address this limitation and expand their utility, this study explored the incorporation of xylitol, a natural antibacterial sugar alcohol, into these polymer matrices to enhance their physicochemical and antimicrobial properties. Electrospinning was employed to fabricate pristine and xylitol-loaded scaffolds with varying xylitol concentrations. Morphological analysis revealed polymer-dependent changes in fiber diameter and porosity. Mechanical testing assessed the impact of xylitol on tensile properties, while thermal analysis investigated alterations in melting temperature and crystallinity. The antibacterial efficacy against Staphylococcus aureus and Escherichia coli was evaluated using WST assay and live/dead staining. Notably, xylitol significantly enhanced the antibacterial activity against both bacterial species, with a more pronounced and rapid effect observed against S. aureus. The tailored scaffold properties and imparted antimicrobial characteristics highlight the potential of these xylitol-modified electrospun materials: they are easily produced, low-cost, and appropriate for a range of applications (dental applications, filters, masks, wound dressing, and packaging) where preventing bacterial contamination is crucial. Full article

(This article belongs to the Section Polymer Composites and Nanocomposites)

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15 pages, 4576 KB

Open AccessEditor’s ChoiceArticle

Impedance-Matched Iron-Added Polymeric Composite Film Incorporated with Iron Nanowire for Electromagnetic Absorption Application

by Yuh-Jing Chiou, Pei-Jung Chang, Pei-Ru Su, Sheng-Jung Tsou and Chung-Kwei Lin

Polymers 2025, 17(21), 2965; https://doi.org/10.3390/polym17212965 - 6 Nov 2025

Viewed by 917

Abstract

Salisbury screen-type radar absorption structures (RASs) consisting of a resistance sheet, a spacer, and a conductive base provide an efficient method for microwave absorption. An impedance-matched resistance sheet allows microwaves to enter, whereas superior microwave absorbers enhance their performance further. In the present [...] Read more.

Salisbury screen-type radar absorption structures (RASs) consisting of a resistance sheet, a spacer, and a conductive base provide an efficient method for microwave absorption. An impedance-matched resistance sheet allows microwaves to enter, whereas superior microwave absorbers enhance their performance further. In the present work, an impedance matching composite film was prepared by using polymer/iron/iron nanowires. By varying the polymer, poly (methyl methacrylate) (PMMA), poly (vinylidene fluoride) (PVDF), and poly (vinyl alcohol) (PVA), to iron powder ratios (1:1, 2:1, and 4:1), composite films were synthesized and examined by scanning electron microscopy, X-ray diffraction, and the four-point probe method to determine the materials’ characteristics. An impedance-matched composite film was prepared based on the selected composition with 1–10 wt.% iron nanowire additions. Experimental results showed that the polymeric composite film prepared by a ratio of iron-PVA of 4:1 exhibited a sheet resistance of 49 ± 9.7 Ω/sq due to well dispersion of iron powder in PVA. With 1 wt.% Fe nanowire addition, the optimal composite sheet resistance was 329.7 ± 45.3 Ω/sq, which corresponded to an impedance matching degree (i.e., |Z_in/Z₀| value) of 0.88 ± 0.12 and can be used as a resistance sheet for a Salisbury screen-type absorber in RAS applications. Full article

(This article belongs to the Section Polymer Composites and Nanocomposites)

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17 pages, 10249 KB

Open AccessEditor’s ChoiceArticle

Mater-Bi-Based Biocomposites Reinforced with Lemongrass: A Comparison Between Leaf- and Culm-Derived Particles

by Manuela Ceraulo, Luigi Botta, Carmelo Sanfilippo, Sanjay Mavinkere Rangappa, Suchart Siengchin and Vincenzo Fiore

Polymers 2025, 17(21), 2909; https://doi.org/10.3390/polym17212909 - 30 Oct 2025

Viewed by 665

Abstract

In this study, aiming to develop novel biocomposites that offer competitive properties while retaining their renewable and biodegradable characteristics, a biodegradable polymer matrix (Mater-Bi^® HF51L2) was reinforced with natural particles extracted from the culm and leaf of Cymbopogon flexuosus (lemongrass). Particles (<500 [...] Read more.

In this study, aiming to develop novel biocomposites that offer competitive properties while retaining their renewable and biodegradable characteristics, a biodegradable polymer matrix (Mater-Bi^® HF51L2) was reinforced with natural particles extracted from the culm and leaf of Cymbopogon flexuosus (lemongrass). Particles (<500 µm) were incorporated at 10 and 20 wt.% via twin-screw extrusion followed by compression moulding. Morphological analysis via SEM revealed distinct structural differences between culm- and leaf-derived particles, with the latter exhibiting smoother surfaces, higher density, and better dispersion in the matrix, resulting in lower void content. Quasi-static mechanical tests showed increased stiffness with filler content, particularly for leaf-based composites. This material, at 20 wt.% filler loadings, enhanced the tensile and flexural moduli of the neat Mater-Bi approximately three and two times, respectively, a result attributed to enhanced interfacial adhesion. Rheological measurements (rotational and capillary) indicated significant increases in complex viscosity, particularly for leaf-filled systems, confirming restricted polymer chain mobility and good matrix–filler interaction. Dynamic mechanical thermal tests (DMTA) results showed an increased storage modulus and a shift in glass transition temperature (T_g) for all biocomposites in comparison to Mater-Bi matrix. Specifically, the neat matrix had a T_g of −28 °C, which increased to −24 °C and −18 °C for the 20 wt.% culm-reinforced and leaf-reinforced biocomposites, respectively. Overall, the leaf-derived particles demonstrated superior reinforcing potential, effectively improving the mechanical, rheological, and thermal properties of Mater-Bi-based biocomposites. Full article

(This article belongs to the Section Polymer Composites and Nanocomposites)

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17 pages, 2578 KB

Open AccessEditor’s ChoiceArticle

Comparing the Printability, Biological and Physicochemical Properties of Bio-Based Photo-Crosslinkable Hydrogels

by Ane García-García, Unai Silván, Leyre Pérez-Álvarez and Senentxu Lanceros

Polymers 2025, 17(21), 2867; https://doi.org/10.3390/polym17212867 - 28 Oct 2025

Cited by 1 | Viewed by 968

Abstract

Bio-based photo-crosslinkable hydrogels are used in tissue engineering as three-dimensional printable scaffolds due to their functional and biological similarities with the extracellular matrix (ECM). In this work, emerging bioink candidates such as chitosan, alginate and gelatin-based photo-crosslinkable hydrogel were developed using extrusion-based 3D [...] Read more.

Bio-based photo-crosslinkable hydrogels are used in tissue engineering as three-dimensional printable scaffolds due to their functional and biological similarities with the extracellular matrix (ECM). In this work, emerging bioink candidates such as chitosan, alginate and gelatin-based photo-crosslinkable hydrogel were developed using extrusion-based 3D printing to establish a better understanding of their applicability. The polymers were methacrylated by the same methacrylation reaction pathway, which enabled successful light-induced 3D printing. Morphology, swelling (6–40%), mechanical (Young’s modulus, 0.1–0.5 KPa) and rheological properties (300–1000 Pa), degradation kinetics (10->60 days) and printability of the gels were also characterized in identical conditions for the first time. 3D-printability results indicated that methacrylated gelatin enhanced printability, shape fidelity and integrity of printed structures compared to methacrylated alginate, which presents structural instability and poorer printing control due to its low crosslink density. Moreover, cell attachment and Live/Dead assays using bone marrow-derived mesenchymal stem cells (BM-MSCs) showed that all formulations have good biocompatibility for use as scaffolds. Specifically, gelatin-based hydrogels showed a higher level of BM-MSCs attachment and spreading than the other types of hydrogels. Overall, our results suggest that the hydrogels based on these three biopolymers present good potential as a biomaterial for light-induced extrusion-based 3D printing. Full article

(This article belongs to the Special Issue Advances in Sustainable Polymeric Materials, 3rd Edition)

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14 pages, 5797 KB

Open AccessEditor’s ChoiceArticle

Investigation of Blade Printing Technique for Nano-Structuring Piezoelectric Polymer Ink in a Porous Anodic Aluminum Oxide

by Tsvetozar Tsanev and Mariya Aleksandrova

Polymers 2025, 17(21), 2839; https://doi.org/10.3390/polym17212839 - 24 Oct 2025

Viewed by 647

Abstract

In this work, we investigated the use of a piezoelectric flexible device for energy harvesting. The main goal of the study was to fill the nanostructured pores of anodic aluminum oxide (AAO) films with piezoelectric polymer (PVDF-TrFE) via a modified conventional screen printing [...] Read more.

In this work, we investigated the use of a piezoelectric flexible device for energy harvesting. The main goal of the study was to fill the nanostructured pores of anodic aluminum oxide (AAO) films with piezoelectric polymer (PVDF-TrFE) via a modified conventional screen printing technique using blade printing. In this way, it is possible to obtain a composite from nanostructured thin films of polymer nanorods that shows improved charge generation ability compared to other non-nanostructured composites or pure (non-composite) aluminum with similar dimensions. This behavior is due to the effect of the highly developed surface of the material used to fill in the AAO nanopore template and its ability to withstand the application of higher mechanical loads to the structured piezoelectric material during deformation. The contact blade print filling technique can produce nanostructured piezoelectric polymer films with precise geometric parameters in terms of thickness and nanorod diameters, at around 200 nm, and a length of 12 μm. At a low frequency of 17 Hz, the highest root-mean-square (RMS) voltage generated using the nanostructured AAO/PVDF-TrFE sample with aluminum electrodes was around 395 mV. At high frequencies above 1700 Hz, the highest RMS voltage generated using the nanostructured AAO/PVDF-TrFE sample with gold electrodes was around 680 mV. The RMS voltage generated using a uniform (non-nanostructured) layer of PVDF-TrFE was 15% lower across the whole frequency range. Full article

(This article belongs to the Special Issue Advanced Polymers for Harnessing Power and Energy)

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25 pages, 1716 KB

Open AccessEditor’s ChoiceReview

Sustainable Valorisation of End-of-Life Tyres Through Pyrolysis-Derived Recovered Carbon Black in Polymer Composites

by Dharanija Banala, Ylias Sabri, Namita Roy Choudhury and Rajarathinam Parthasarathy

Polymers 2025, 17(20), 2771; https://doi.org/10.3390/polym17202771 - 16 Oct 2025

Viewed by 3171

Abstract

More than one billion end-of-life tyres (EOLTs) are produced worldwide every year, and this is continuously increasing and has become an issue in sustainable development. This review discusses recent developments in the management of EOLTs and focuses on pyrolysis, which produces valuable tyre-derived [...] Read more.

More than one billion end-of-life tyres (EOLTs) are produced worldwide every year, and this is continuously increasing and has become an issue in sustainable development. This review discusses recent developments in the management of EOLTs and focuses on pyrolysis, which produces valuable tyre-derived products (TDPs) like steel, gas, oil, and char. This review focuses on recovered carbon black (rCB), a refined char with great potential as a sustainable alternative to commercial carbon black (CB). The review introduces a novel classification system for CB, virgin carbon black (vCB), recovered carbon black (rCB), and sustainable carbon black (sCB) to guide the transition toward environmentally friendly materials. It also examines how rCB enhances polymer properties for addressing price volatility and reducing carbon footprint. Additionally, a SWOT analysis evaluates the strengths (cost-effectiveness, reduced environmental impact), weaknesses (quality consistency), opportunities (emerging markets, circular economy integration), and threats (competition from virgin materials) of using rCB as a polymer reinforcement. By positioning rCB as a key material, this review outlines pathways for addressing the EOLT crisis and advancing a circular economy. Full article

(This article belongs to the Special Issue Polymer Recycling and Upcycling: Toward a Circular Materials Economy)

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17 pages, 4400 KB

Open AccessEditor’s ChoiceArticle

Advanced Polyamidoamine Hydrogels for the Selective Cleaning of Artifacts in Heritage Conservation

by Elisabetta Ranucci and Jenny Alongi

Polymers 2025, 17(19), 2680; https://doi.org/10.3390/polym17192680 - 3 Oct 2025

Viewed by 838

Abstract

A polyamidoamine-based hydrogel (H-M-GLY) and its montmorillonite-based composite (H-M-GLY/MMT) were studied as selective cleaning materials for cultural heritage conservation. H-M-GLY was synthesized from a glycine-based polyamidoamine oligomer with acrylamide terminals (M-GLY) through radical polymerization at pH 7.3 and had a basic character. The [...] Read more.

A polyamidoamine-based hydrogel (H-M-GLY) and its montmorillonite-based composite (H-M-GLY/MMT) were studied as selective cleaning materials for cultural heritage conservation. H-M-GLY was synthesized from a glycine-based polyamidoamine oligomer with acrylamide terminals (M-GLY) through radical polymerization at pH 7.3 and had a basic character. The M-GLY oligomer was in turn synthesized from N,N′-methylenebisacrylamide and glycine in a 1:0.85 molar ratio. H-M-GLY/MMT was obtained by cross-linking a 1:0.1—weight ratio—M-GLY/MMT mixture at pH 4.0, to promote polyamidoamine-MMT interaction. The composite hydrogel absorbed less water than the plain hydrogel and proved tougher, due to montmorillonite’s electrostatic interactions with the positively charged M-GLY units. Scanning electron microscopic analysis showed that MMT was uniformly dispersed throughout the hydrogel. Both hydrogels were subjected to ink bleeding tests on papers written with either iron gall or India ink. Microscopic observation revealed neither bleeding nor release of hydrogel fragments. Being basic, H-M-GLY successfully deacidified the surface of aged paper. H-M-GLY/MMT, swollen in a 1:9 ethanol/water solution, was found to be effective in removing wax, known to trap carbonaceous particles and form dark stains on artistic artifacts. This study demonstrates the great potential of polyamidoamine-based hydrogels as versatile selective cleaning systems for cellulosic and other cultural heritage materials. Full article

(This article belongs to the Section Polymer Chemistry)

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14 pages, 1429 KB

Open AccessEditor’s ChoiceArticle

Diffusion Behavior of Polyethylene Furanoate (PEF) and Tritan as Sustainable Polyester Packaging Materials

by Frank Welle

Polymers 2025, 17(19), 2674; https://doi.org/10.3390/polym17192674 - 2 Oct 2025

Viewed by 1742

Abstract

Polyethylene furanoate (PEF) and Tritan^TM copolyester are sustainable polyester polymers. PEF is made from biobased resources, whereas Tritan is mainly used for reusable food contact articles. Both polyesters are alternatives for polyethylene terephthalate (PET), which is currently the most used polyester in [...] Read more.

Polyethylene furanoate (PEF) and Tritan^TM copolyester are sustainable polyester polymers. PEF is made from biobased resources, whereas Tritan is mainly used for reusable food contact articles. Both polyesters are alternatives for polyethylene terephthalate (PET), which is currently the most used polyester in food packaging. Like all packaging polymers, sustainable alternatives to fossil-based PET must also comply with food law requirements. Prediction of the migration can be used as an alternative to complex and time-consuming experimental migration measurements. Since there are no such predictive models for either PEF or Tritan, the modelling parameters for PEF and Tritan were determined in this study from experimentally determined diffusion coefficients and activation energies. The diffusivity of PEF and Tritan was compared with PET and polyethylene naphthalate (PEN). Of the four polyester polymers, PEF shows the lowest diffusion, followed by PEN, PET, and Tritan. Overall, the results show that the investigated polyesters are low-diffusivity polymers. Full article

(This article belongs to the Section Polymer Applications)

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12 pages, 717 KB

Open AccessEditor’s ChoiceArticle

Molecular Properties of Starch–Water Interactions in the Presence of Bioactive Compounds from Barley and Buckwheat—LF NMR Preliminary Study

by Greta Adamczyk, Łukasz Masewicz, Krzysztof Przybył, Aleksandra Zaryczniak, Przemysław Łukasz Kowalczewski, Monika Beszterda-Buszczak, Wojciech Cichocki and Hanna Maria Baranowska

Polymers 2025, 17(19), 2606; https://doi.org/10.3390/polym17192606 - 26 Sep 2025

Viewed by 912

Abstract

The retrogradation of starch strongly influences the texture and stability of starchy foods. This study applied low-field nuclear magnetic resonance (LF NMR) to examine the effect of buckwheat hull (BH) fiber and green barley (GB) on water dynamics in normal (NPS) and waxy [...] Read more.

The retrogradation of starch strongly influences the texture and stability of starchy foods. This study applied low-field nuclear magnetic resonance (LF NMR) to examine the effect of buckwheat hull (BH) fiber and green barley (GB) on water dynamics in normal (NPS) and waxy (WPS) potato starch gels. Relaxation times (T₁, T₂) and mean correlation times (τ_c) were monitored during 15 days of storage to evaluate changes in water mobility and starch–polymer interactions. Results showed that WPS, with its high amylopectin content, retrograded earlier than NPS. The addition of BH inhibited conformational changes associated with water binding in WPS gels, indicating that insoluble fiber entrapped water within the amylopectin network. Conversely, GB promoted higher τ_c values in WPS, reflecting enhanced ordering and reduced water mobility, while its impact on NPS was minor. In NPS systems, BH decreased τ_c, suggesting disruption of amylose-driven structural reorganization. These findings demonstrate that BH and GB exert opposite effects on starch retrogradation and highlight their potential as functional additives for tailoring texture and stability in starch-based food systems. Full article

(This article belongs to the Special Issue Advanced Spectroscopy for Polymers: Design and Characterization)

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17 pages, 3397 KB

Open AccessEditor’s ChoiceArticle

Preparation and Performance of Poly(Butylene Succinate) (PBS) Composites Reinforced with Taxus Residue and Compatibilized with Branched PBS

by Shiwanyi Chen, Shufeng Li, Bing Wang, Chen Chen and Liuchun Zheng

Polymers 2025, 17(19), 2597; https://doi.org/10.3390/polym17192597 - 25 Sep 2025

Viewed by 1853

Abstract

In response to the escalating plastic pollution crisis, the development of high-performance biodegradable materials is critical. Poly(butylene succinate) (PBS) is an important biodegradable polymer as it possesses excellent biodegradability and processability. But it suffers from limitations such as low mechanical strength, poor thermal [...] Read more.

In response to the escalating plastic pollution crisis, the development of high-performance biodegradable materials is critical. Poly(butylene succinate) (PBS) is an important biodegradable polymer as it possesses excellent biodegradability and processability. But it suffers from limitations such as low mechanical strength, poor thermal stability, and high production costs. In this study, taxus residue (TF), a waste by-product, was utilized as a reinforcing filler to reduce PBS costs while enhancing its overall performance. To address the interfacial incompatibility between TF and PBS, branched PBS (T-PBS) was introduced as a compatibilizer. The TF was surface-modified via alkali treatment and silane coupling (KH550), and a series of PBS/TF/T-PBS composites with varying T-PBS viscosity grades were prepared by melt blending. The compatibilization mechanism of T-PBS and its influence on the composite structure, crystallization behavior, thermal stability, rheological, and mechanical properties were systematically investigated. Results show that the branched structure significantly enhanced T-PBS melt strength and reactivity. The introduction of T-PBS effectively improved interfacial compatibility between TF and PBS matrix, reducing phase separation and interfacial defects. Compared to uncompatibilized PBS/TF composites, those with appropriately viscous T-PBS exhibited improved tensile strength (increased by 19.7%) and elongation at break (increased by 78.8%), while flexural strength was also maintained at an enhanced level. The branched points acted as nucleating agents, increasing the onset temperature and degree of crystallinity. In the high-temperature region, the synergistic barrier effect from TF and char residue improved thermal stability (T_85% reached 408.19 °C). Rheological analysis revealed enhanced viscosity and elasticity of the system. This study provides a promising strategy and theoretical foundation for the high-value utilization of taxus waste and the development of high-performance biodegradable PBS-based composites. Full article

(This article belongs to the Special Issue Advancing Polyester: Novel Approaches and Applications in Materials Science)

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19 pages, 3468 KB

Open AccessEditor’s ChoiceArticle

Density-Based Topology-Optimized 3D-Printed Fixtures for Cyclic Mechanical Testing of Lattice Structures

by Josué Castro, Rodrigo Valle, Jorge Leiva, Angelo Oñate, Enrico Saggionetto, Anne Mertens and Víctor Tuninetti

Polymers 2025, 17(18), 2468; https://doi.org/10.3390/polym17182468 - 12 Sep 2025

Cited by 5 | Viewed by 1603

Abstract

The reliable experimental characterization of architected lattice materials under cyclic loading requires accurate fixture systems that ensure proper load transfer without introducing parasitic effects. This study presents the design and validation of testing fixtures optimized using density-based topological optimization techniques for performing cyclic [...] Read more.

The reliable experimental characterization of architected lattice materials under cyclic loading requires accurate fixture systems that ensure proper load transfer without introducing parasitic effects. This study presents the design and validation of testing fixtures optimized using density-based topological optimization techniques for performing cyclic load tests on lattice structures. The supports were manufactured with PLA filaments and evaluated using finite element simulation and experimental testing. The results show that the final design achieved a safety factor of 4.25, significantly improving on the initial value of 2.08. Likewise, the optimized supports showed reduced deformations by around 80% compared to the machine clamps, ensuring rigid and reliable stress transfer. In particular, while the metal structure of the test system showed deformations of several millimeters, the optimized PLA supports recorded displacements around 0.73 mm, confirming that they remain virtually rigid and ensure correct transmission of forces to the Kelvin-type structure. These findings confirm the viability of using PLA as an alternative to conventional metal devices in fixtures for mechanical testing of lattice materials. Full article

(This article belongs to the Special Issue High-Performance Polymer Materials and Fiber-Reinforced Composites for Engineering Applications)

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14 pages, 4453 KB

Open AccessEditor’s ChoiceArticle

Two-Component Response Regulators CitT, YvcP, and YycI Differentially Control Pectin and Hemicellulose Degradation in Degumming of Ramie Fibers by Bacillus subtilis Strain 168

by Qi Yang, Shihang Ma, Lifeng Cheng, Xiang Zhou, Guoguo Xi, Chen Chen, Zhenghong Peng, Yuqin Hu, Si Tan and Shengwen Duan

Polymers 2025, 17(18), 2473; https://doi.org/10.3390/polym17182473 - 12 Sep 2025

Cited by 1 | Viewed by 702

Abstract

Exploring the metabolic regulatory mechanisms of bacteria for ramie degumming and constructing more efficient engineered strains are preferred strategies to solve the technical bottleneck of high residual gum content in fibers. Bacillus subtilis strain 168, an advantageous bacterium for microbial degumming, was previously [...] Read more.

Exploring the metabolic regulatory mechanisms of bacteria for ramie degumming and constructing more efficient engineered strains are preferred strategies to solve the technical bottleneck of high residual gum content in fibers. Bacillus subtilis strain 168, an advantageous bacterium for microbial degumming, was previously found to significantly up-regulate the expression of bast two-component system (TCS) response regulators CitT, YvcP, and YycI when using ramie as the sole carbon source. In this study, the genes encoding CitT, YvcP, and YycI proteins were knocked out and compared the effects between these gene knockouts and the original strain on the degumming efficiency. The aim was to identify the key TCS response regulators that significantly affect degumming efficiency and to explore the functions of these different response regulators. The results demonstrated that knockout of citT, yvcP, or yycI genes significantly reduced degumming efficiency. Specifically, CitT protein primarily regulated the degradation of pectin, YvcP protein mainly regulated the degradation of hemicellulose, and YycI protein was involved in the regulation of both pectin and hemicellulose degradation. Notably, the absence of CitT protein caused the most significant reduction in degumming efficiency. These findings provide valuable insights into the construction of engineered strains with high degumming efficiency for ramie fibers. Full article

(This article belongs to the Special Issue Application and Characterization of Cellulose-Based Polymers)

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19 pages, 3530 KB

Open AccessEditor’s ChoiceReview

Direct Analysis of Solid-Phase Carbohydrate Polymers by Infrared Multiphoton Dissociation Reaction Combined with Synchrotron Radiation Infrared Microscopy and Electrospray Ionization Mass Spectrometry

by Takayasu Kawasaki, Heishun Zen, Kyoko Nogami, Ken Hayakawa, Takeshi Sakai and Yasushi Hayakawa

Polymers 2025, 17(17), 2273; https://doi.org/10.3390/polym17172273 - 22 Aug 2025

Viewed by 1341

Abstract

To determine the structure of carbohydrate polymers using conventional analytical technology, several complicated steps are required. We instead adopted a direct approach without the need for pretreatments, using an intense infrared (IR) laser for carbohydrate analysis. IR free-electron lasers (FELs) driven by a [...] Read more.

To determine the structure of carbohydrate polymers using conventional analytical technology, several complicated steps are required. We instead adopted a direct approach without the need for pretreatments, using an intense infrared (IR) laser for carbohydrate analysis. IR free-electron lasers (FELs) driven by a linear accelerator possess unique spectroscopic features, including extensive wavelength tunability and high laser energy in the IR region from 1000 cm⁻¹ (10 μm) to 4000 cm⁻¹ (2.5 μm). FELs can induce IR multiphoton dissociation reactions against various molecules by supplying vibrational excitation energy to the corresponding chemical bonds. Chitin from crayfish and cellulose fiber were irradiated by FELs tuned to νC–O (9.1–9.8 μm), νC–H (3.5 μm), and δH–C–O (7.2 μm) in glycosidic bonds, and their low-molecular-weight sugars were separated, which were revealed by combining synchrotron radiation IR spectroscopy and electrospray ionization mass spectrometry. An intense IR laser can be viewed as a “molecular scalpel” for dissecting and directly analyzing the internal components in rigid biopolymers. This method is simple and rapid compared with general analytical techniques. Full article

(This article belongs to the Special Issue Advanced Spectroscopy for Polymers: Design and Characterization)

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24 pages, 4305 KB

Open AccessEditor’s ChoiceArticle

Driving the Green Transition: Innovative Tyre Formulation Using Agricultural and Pyrolysed Tyres Waste

by Carlo Di Bernardo, Francesca Demichelis, Mehran Dadkhah, Debora Fino, Massimo Messori and Camilla Noè

Polymers 2025, 17(17), 2275; https://doi.org/10.3390/polym17172275 - 22 Aug 2025

Viewed by 1463

Abstract

The rubber industry is facing increasing pressure to adopt sustainable practices due to environmental concerns associated with the use of non-renewable resources and the growing accumulation of waste tyres and agricultural byproducts. This study explores the potential of partially replacing conventional carbon black [...] Read more.

The rubber industry is facing increasing pressure to adopt sustainable practices due to environmental concerns associated with the use of non-renewable resources and the growing accumulation of waste tyres and agricultural byproducts. This study explores the potential of partially replacing conventional carbon black (CB) with sustainable alternatives derived from agricultural waste (wine by-products) and pyrolysed waste tyres in natural rubber/styrene-butadiene rubber (NR/SBR) composites for tyre applications. A series of NR/SBR composites were formulated with varying ratios of CB to agricultural waste and pyrolysed tyre waste, while maintaining consistent levels of other additives. The resulting composites were then subjected to a comprehensive suite of analyses, including scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) surface area measurements, Fourier transform infrared spectroscopy (FTIR), bound rubber content determination, Payne effect analysis, thermogravimetric analysis (TGA), dynamic mechanical thermal analysis (DMTA), and mechanical property testing. Furthermore, a Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) analysis were conducted to evaluate the environmental and economic viability of the proposed CB replacements. The results reveal that the incorporation of agricultural waste and pyrolysed tyre waste can significantly impact the curing behaviour, mechanical properties, and thermal stability of rubber composites. Importantly, some of the formulations demonstrate comparable tensile strength, elongation at break, and hardness compared to traditional CB-filled composites. The LCA and LCC analyses further highlight the potential for substantial reductions in greenhouse gas emissions, fossil resource depletion, and overall production costs, thereby supporting the transition toward more sustainable tyre manufacturing practices. Full article

(This article belongs to the Special Issue Sustainable Bio-Based and Circular Polymers and Composites)

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27 pages, 4903 KB

Open AccessEditor’s ChoiceArticle

Biodegradation in Freshwater: Comparison Between Compostable Plastics and Their Biopolymer Matrices

by Valerio Bocci, Martina De Vivo, Sara Alfano, Simona Rossetti, Francesca Di Pippo, Loris Pietrelli and Andrea Martinelli

Polymers 2025, 17(16), 2236; https://doi.org/10.3390/polym17162236 - 17 Aug 2025

Cited by 2 | Viewed by 2121

Abstract

Plastic pollution in freshwater ecosystems is an increasing environmental concern, prompting the search for biodegradable polymer (BP) alternatives. However, their degradation in natural aquatic environments remains poorly investigated and understood. This four-month in situ study compared the degradation in a lentic freshwater ecosystem [...] Read more.

Plastic pollution in freshwater ecosystems is an increasing environmental concern, prompting the search for biodegradable polymer (BP) alternatives. However, their degradation in natural aquatic environments remains poorly investigated and understood. This four-month in situ study compared the degradation in a lentic freshwater ecosystem of two compostable items, Mater-Bi^® shopping bag and disposable dish, with their respective pure polymer matrices, poly(butylene adipate-co-terephthalate) (PBAT) and polylactic acid (PLA). Additionally, biodegradable poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and oil-based polypropylene (PP) were also tested. Changes in morphology, chemical composition and thermal and mechanical properties, as well as microbial colonization, were analyzed over time. A validated cleaning protocol was employed to ensure accurate surface analysis. Results showed detectable but limited degradation of pure polymers and their matrices in commercial products after 120 days of immersion with variations observed among polymer materials. Compostable materials exhibited significant leaching of fillers (starch, inorganic particles), leading to morphological changes and fragmentation. PHBV showed the fastest degradation among tested polyesters. PP exhibited only minor surface changes. Microbial colonization varied with polymer structure and degradability, but long-term degradation was limited by polymer properties and the gradual development of the plastisphere. This study highlights that standard laboratory tests may overestimate the environmental degradability of BPs and emphasizes the importance of in situ assessments, careful cleaning procedures and property characterizations to accurately assess polymer degradation in freshwater systems. Full article

(This article belongs to the Special Issue Natural Degradation of Polymers)

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14 pages, 3778 KB

Open AccessEditor’s ChoiceArticle

A New Recycling Technology to Produce Premixed Thermal Insulating Mortars from Polyurethane Waste Foams

by Antonis Kountouris, Kypros Efstathiou, Nikolaos Kostoglou, Dimitrios Manolakos and Claus Rebholz

Polymers 2025, 17(16), 2233; https://doi.org/10.3390/polym17162233 - 17 Aug 2025

Viewed by 1472

Abstract

The increasing demand for sustainable construction materials has driven research into the reuse of plastic waste for renewable building applications. This study introduces a new lightweight insulating mortar for floor and roof systems, utilizing recycled rigid polyurethane (PU) foam as the primary aggregate. [...] Read more.

The increasing demand for sustainable construction materials has driven research into the reuse of plastic waste for renewable building applications. This study introduces a new lightweight insulating mortar for floor and roof systems, utilizing recycled rigid polyurethane (PU) foam as the primary aggregate. The binder mainly consists of Portland cement, with no added sand, and includes minor additives to enhance mechanical, physical, and thermal properties. Initial tests demonstrated that key performance metrics—density, compressive strength, and thermal conductivity—are significantly influenced by the PU content. As the proportion of PU increased, all three parameters decreased. The optimized formulation, comprising 92.25 vol.% PU foam, 6.75 vol.% cement, and 1 vol.% additives, achieved a low bulk density of 420 kg/m³, a compressive strength of 1 MPa, and a thermal conductivity of 0.07 W/m·K. A pilot-scale production system with a capacity of 1500 L/h (equivalent to 20 bags of 75 L) was subsequently designed, implemented, and validated. These findings underscore the potential of PU-based lightweight insulating mortars to reduce environmental impact and support the development of sustainable construction practices globally. Full article

(This article belongs to the Special Issue Sustainable Polymeric Materials in Building and Construction)

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26 pages, 7957 KB

Open AccessEditor’s ChoiceArticle

Elastoplastic Modeling of Kevlar^® Composite Laminates: A Cyclic Loading Approach for In-Plane Characterization

by Rene Alejandro Canceco de la Cruz, Luis Adrián Zúñiga Avilés, Gabriel Plascencia Barrera, Alberto Díaz Díaz and José Martin Herrera Ramírez

Polymers 2025, 17(16), 2235; https://doi.org/10.3390/polym17162235 - 17 Aug 2025

Viewed by 1207

Abstract

This study investigates the elastoplastic behavior of phenol formaldehyde/polyvinyl butyral matrix (70% PF/30% PVB) reinforced with Kevlar^® fibers through comprehensive in-plane tensile testing. Cyclic loading–unloading tests were conducted at a 100%/min strain rate using a universal testing system at room temperature on [...] Read more.

This study investigates the elastoplastic behavior of phenol formaldehyde/polyvinyl butyral matrix (70% PF/30% PVB) reinforced with Kevlar^® fibers through comprehensive in-plane tensile testing. Cyclic loading–unloading tests were conducted at a 100%/min strain rate using a universal testing system at room temperature on

(0_{4})

,

(90_{4})

, and

{(\pm 45)}_{s}

laminates. The experimental results revealed significant nonlinear hardening behavior beyond yield stress, accompanied by yarn stiffening effects during loading cycles. A novel elastoplastic constitutive model was developed, incorporating Hill’s yield criterion adapted for orthotropic materials and an isotropic hardening function that accounts for equivalent plastic strains and progressive yarn stiffening. Laminates with other stacking sequences were also tested and the accuracy of the predictions of the nonlinear behavior was assessed. In these laminates, delaminations took place and the model provided an overestimation of the stress–strain response. Since the model could not predict delamination onset and propagation, an adaptation of the model considering fully delaminated interfaces brought a lower bound of this response. Despite the limitations of the model, it can be used to provide reasonable limits to the stress–strain response of laminates accounting for plastic strains within plies. This study provides essential mechanical properties and constitutive relationships for designing Kevlar^® composite structures with tailored stiffness characteristics for impact-resistant applications. Full article

(This article belongs to the Special Issue Constitutive Modeling of Polymer Matrix Composites)

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21 pages, 1652 KB

Open AccessEditor’s ChoiceArticle

Antimicrobial and Physicochemical Properties of Hemicellulose-Based Films Incorporating Carvacrol

by Syed Ammar Hussain, Brajendra K. Sharma, Phoebe X. Qi, Madhav P. Yadav and Tony Z. Jin

Polymers 2025, 17(15), 2073; https://doi.org/10.3390/polym17152073 - 29 Jul 2025

Cited by 4 | Viewed by 1379

Abstract

Antimicrobial food packaging with natural antimicrobials and biodegradable polymers presents an innovative solution to mitigate microbial contamination, prolong freshness, reduce food waste, and alleviate environmental burden. This study developed antimicrobial hemicellulose-based films by incorporating carvacrol (1% and 2%) as a natural antimicrobial agent [...] Read more.

Antimicrobial food packaging with natural antimicrobials and biodegradable polymers presents an innovative solution to mitigate microbial contamination, prolong freshness, reduce food waste, and alleviate environmental burden. This study developed antimicrobial hemicellulose-based films by incorporating carvacrol (1% and 2%) as a natural antimicrobial agent through micro-emulsification produced by high-pressure homogenization (M-films). For comparison, films with the same formula were constructed using coarse emulsions (C-films) without high-pressure homogenization. These films were investigated for their antimicrobial efficacy, mechanical and barrier properties, and physicochemical attributes to explore their potential as sustainable antimicrobial packaging solutions. The M-films demonstrated superior antimicrobial activity, achieving reductions exceeding 4 Log CFU/mL against Listeria monocytogenes, Escherichia coli, and Salmonella enterica, compared to the C-films. High-pressure homogenization significantly reduced the emulsion’s particle size, from 11.59 to 2.55 μm, and considerably enhanced the M-film’s uniformity, hydrophobicity, and structural quality. Most importantly, the M-films exhibited lower oxygen transmission (35.14 cc/m²/day) and water vapor transmission rates (52.12 g/m²/day) than the C-films at 45.1 and 65.5 cc/m²/day, respectively, indicating superior protection against gas and moisture diffusion. Markedly improved mechanical properties, including foldability, toughness, and bubble-free surfaces, were also observed, making the M-films suitable for practical applications. This study highlights the potential of high-pressure homogenization as a method for enhancing the functional properties of hemicellulose-based films (i.e., M-films). The fabricated films offer a viable alternative to conventional plastic packaging, paving the way for safer and greener solutions tailored to modern industry needs. Full article

(This article belongs to the Special Issue Polymer-Based Coatings: Principles, Development and Applications)

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13 pages, 4630 KB

Open AccessEditor’s ChoiceArticle

Electrospun Polymeric Composite Fibers Containing Te-Doped Bioactive Glass Powders

by Marta Miola, Elisa Piatti, Francesco Iorio, Aldo R. Boccaccini and Enrica Verné

Polymers 2025, 17(15), 2057; https://doi.org/10.3390/polym17152057 - 28 Jul 2025

Viewed by 871

Abstract

In this work, the electrospinning technique was used to prepare novel polymeric composite fibers containing Te-doped bioactive glass powders. Bioactive glass powders containing tellurium (STe5 glass) were chosen as fillers for the composites, owing to their bioactive, antibacterial, and antioxidant properties. The biopolymer [...] Read more.

In this work, the electrospinning technique was used to prepare novel polymeric composite fibers containing Te-doped bioactive glass powders. Bioactive glass powders containing tellurium (STe5 glass) were chosen as fillers for the composites, owing to their bioactive, antibacterial, and antioxidant properties. The biopolymer poly (ϵ-caprolactone) (PCL) and acetic acid (AA) were used as raw materials for the preparation of the polymeric matrix. FESEM analysis confirmed a good incorporation of the glass powders in the polymeric fibers, of up to 20% by weight. Wettability, mechanical, in vitro stability and preliminary antibacterial tests were also performed. The results showed that the treatment in AA did not affect the bioactivity of the glass powders, the presence of STe5 powders in PCL enhanced the wettability of the fibers, and mechanical properties improved by increasing the amount of STe5 powders, as well as the antibacterial effect. Therefore, the obtained materials appear promising for developing multifunctional composite materials for applications in tissue engineering. Full article

(This article belongs to the Section Polymer Composites and Nanocomposites)

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17 pages, 2025 KB

Open AccessEditor’s ChoiceArticle

Retainment of Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) Properties from Oil-Fermented Cupriavidus necator Using Additional Ethanol-Based Defatting Process

by Tae-Rim Choi, Gaeun Lim, Yebin Han, Jong-Min Jeon, Shashi Kant Bhatia, Hyun June Park, Jeong Chan Joo, Hee Taek Kim, Jeong-Jun Yoon and Yung-Hun Yang

Polymers 2025, 17(15), 2058; https://doi.org/10.3390/polym17152058 - 28 Jul 2025

Cited by 1 | Viewed by 1121

Abstract

Engineering of Cupriavidus necator could enable the production of various polyhydroxyalkanoates (PHAs); particularly, poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (P(3HB-co-3HH)), a biopolymer with enhanced mechanical and thermal properties compared to poly(3-hydroxybutyrate) (PHB), can be efficiently produced from vegetable oils. However, challenges remain in the [...] Read more.

Engineering of Cupriavidus necator could enable the production of various polyhydroxyalkanoates (PHAs); particularly, poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (P(3HB-co-3HH)), a biopolymer with enhanced mechanical and thermal properties compared to poly(3-hydroxybutyrate) (PHB), can be efficiently produced from vegetable oils. However, challenges remain in the recovery process, particularly in removing residual oil and minimizing degradation of the polymer structure during extraction steps. This study investigated the effects of ethanol-based defatting on the recovery and polymeric properties of P(3HB-co-3HH). The proposed method involves the addition of ethanol to the cell broth to effectively remove residual oil. Ethanol improved the separation of microbial cells from the broth, thereby streamlining the downstream recovery process. Using ethanol in the washing step increased the recovery yield and purity to 95.7% and 83.4%, respectively (compared to 87.4% and 76.2% for distilled water washing), representing improvements of 8.3% and 7.2%. Ethanol washing also resulted in a 19% higher molecular weight compared to water washing, indicating reduced polymer degradation. In terms of physical properties, the elongation at break showed a significant difference: 241.9 ± 27.0% with ethanol washing compared to water (177.7 ± 10.3%), indicating ethanol washing retains flexibility. Overall, an ethanol washing step for defatting could simplify the recovery steps, increase yield and purity, and retain mechanical properties, especially for P(3HB-co-3HH) from oils. Full article

(This article belongs to the Special Issue The Development of Polymeric Biomaterials Using Agro-Industrial Residues)

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18 pages, 4008 KB

Open AccessEditor’s ChoiceArticle

Carboxymethyl Chitosan Cinnamaldehyde Coated SilverNanocomposites for Antifungal Seed Priming in Wheat: A Dual-Action Approach Toward Sustainable Crop Protection

by María Mondéjar-López, María Paz García-Simarro, Lourdes Gómez-Gómez, Oussama Ahrazem and Enrique Niza

Polymers 2025, 17(15), 2031; https://doi.org/10.3390/polym17152031 - 25 Jul 2025

Cited by 1 | Viewed by 1057

Abstract

Biogenic silver nanoparticles (AgNPs) were synthesized via a green chemistry strategy using wheat extract and subsequently functionalized with a carboxymethyl chitosan–cinnamaldehyde (CMC=CIN) conjugate through covalent imine bonding. The resulting nanohybrid (AgNP–CMC=CIN) was extensively characterized to confirm successful biofunctionalization: UV–Vis spectroscopy revealed characteristic cinnamaldehyde [...] Read more.

Biogenic silver nanoparticles (AgNPs) were synthesized via a green chemistry strategy using wheat extract and subsequently functionalized with a carboxymethyl chitosan–cinnamaldehyde (CMC=CIN) conjugate through covalent imine bonding. The resulting nanohybrid (AgNP–CMC=CIN) was extensively characterized to confirm successful biofunctionalization: UV–Vis spectroscopy revealed characteristic cinnamaldehyde absorption peaks; ATR-FTIR spectra confirmed polymer–terpene bonding; and TEM analysis evidenced uniform nanoparticle morphology. Dynamic light scattering (DLS) measurements indicated an increase in hydrodynamic size upon coating (from 59.46 ± 12.63 nm to 110.17 ± 4.74 nm), while maintaining low polydispersity (PDI: 0.29 to 0.27) and stable surface charge (zeta potential ~ −30 mV), suggesting colloidal stability and homogeneous polymer encapsulation. Antifungal activity was evaluated against Fusarium oxysporum, Penicillium citrinum, Aspergillus niger, and Aspergillus brasiliensis. The minimum inhibitory concentration (MIC) against F. oxysporum was significantly reduced to 83 μg/mL with AgNP–CMC=CIN, compared to 708 μg/mL for uncoated AgNPs, and was comparable to the reference fungicide tebuconazole (52 μg/mL). Seed priming with AgNP–CMC=CIN led to improved germination (85%) and markedly reduced fungal colonization, while maintaining a favorable phytotoxicity profile. These findings highlight the potential of polysaccharide-terpene-functionalized biogenic AgNPs as a sustainable alternative to conventional fungicides, supporting their application in precision agriculture and integrated crop protection strategies. Full article

(This article belongs to the Special Issue Polymer Materials for Environmental Applications)

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61 pages, 2268 KB

Open AccessEditor’s ChoiceReview

Biodegradable Polymers: Properties, Applications, and Environmental Impact

by Rashid Dallaev, Nikola Papež, Mohammad M. Allaham and Vladimír Holcman

Polymers 2025, 17(14), 1981; https://doi.org/10.3390/polym17141981 - 18 Jul 2025

Cited by 29 | Viewed by 11747

Abstract

The accelerating global demand for sustainable materials has brought biodegradable polymers to the forefront of scientific and industrial innovation. These polymers, capable of decomposing through biological processes into environmentally benign byproducts, are increasingly seen as viable alternatives to conventional plastics in sectors such [...] Read more.

The accelerating global demand for sustainable materials has brought biodegradable polymers to the forefront of scientific and industrial innovation. These polymers, capable of decomposing through biological processes into environmentally benign byproducts, are increasingly seen as viable alternatives to conventional plastics in sectors such as packaging, agriculture, and biomedicine. However, despite significant advancements, the field remains fragmented due to the diversity of raw materials, synthesis methods, degradation mechanisms, and application requirements. This review aims to provide a comprehensive synthesis of the current state of biodegradable polymer development, including their classifications, sources (natural, synthetic, and microbially derived), degradation pathways, material properties, and commercial applications. It highlights critical scientific and technological challenges—such as optimizing degradation rates, ensuring mechanical performance, and scaling up production from renewable feedstocks. By consolidating recent research findings and regulatory considerations, this review serves as a crucial reference point for researchers, material scientists, and policymakers. It strives to bridge knowledge gaps in order to accelerate the deployment of biodegradable polymers as integral components of a circular and low-impact material economy. Full article

(This article belongs to the Special Issue Biodegradable Polymers for Sustainable Solutions: Innovations and Applications)

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23 pages, 5750 KB

Open AccessEditor’s ChoiceArticle

Effect of Irradiated Nanocellulose on Enhancing the Functionality of Polylactic Acid-Based Composite Films for Packaging Applications

by Ilaria Improta, Mariamelia Stanzione, Elena Orlo, Fabiana Tescione, Marino Lavorgna, Xavier Coqueret and Giovanna G. Buonocore

Polymers 2025, 17(14), 1939; https://doi.org/10.3390/polym17141939 - 15 Jul 2025

Cited by 1 | Viewed by 1619

Abstract

This study investigates the combined use of electron beam irradiation (EBI) and nanotechnology to develop improved food packaging films. EBI, commonly applied for sterilization, can alter polymer microstructure, while irradiated cellulose nanocrystals (CNCs) offer enhanced functionality when incorporated into biopolymer matrices. Here, CNCs [...] Read more.

This study investigates the combined use of electron beam irradiation (EBI) and nanotechnology to develop improved food packaging films. EBI, commonly applied for sterilization, can alter polymer microstructure, while irradiated cellulose nanocrystals (CNCs) offer enhanced functionality when incorporated into biopolymer matrices. Here, CNCs were irradiated with doses up to 50 kGy, leading to the formation of carboxyl and aldehyde groups, confirmed by FTIR analysis, as a consequence of the initial formation of free radicals and peroxides that may subsist in that original form or be converted into various carbonyl groups. Flexible films were obtained by incorporating pristine and EB-irradiated CNCs in an internal mixer, using minute amounts of poly(ethylene oxide) (PEO) to facilitate the dispersion of the filler within the polymer matrix. The resulting PLA/PEO/CNC films were evaluated for their mechanical, thermal, barrier, and antioxidant properties. The results showed that structural modifications of CNCs led to significant enhancements in the performance of the composite films, including a 30% improvement in water barrier properties and a 50% increase in antioxidant activity. These findings underscore the potential of irradiated CNCs as effective additives in biopolymer-based active packaging, offering a sustainable approach to reduce dependence on synthetic preservatives and potentially extend the shelf life of food products. Full article

(This article belongs to the Special Issue Sustainable Polymers for Value Added and Functional Packaging)

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21 pages, 4000 KB

Open AccessEditor’s ChoiceArticle

Structure-Properties Correlations of PVA-Cellulose Based Nanocomposite Films for Food Packaging Applications

by Konstantinos Papapetros, Georgios N. Mathioudakis, Dionysios Vroulias, Nikolaos Koutroumanis, George A. Voyiatzis and Konstantinos S. Andrikopoulos

Polymers 2025, 17(14), 1911; https://doi.org/10.3390/polym17141911 - 10 Jul 2025

Cited by 6 | Viewed by 2385

Abstract

Bio-nanocomposites based on poly (vinyl alcohol) (PVA) and cellulosic nanostructures are favorable for active food packaging applications. The current study systematically investigates the mechanical properties, gas permeation, and swelling parameters of PVA composites with cellulose nanocrystals (CNC) or nano lignocellulose (NLC) fibers. Alterations [...] Read more.

Bio-nanocomposites based on poly (vinyl alcohol) (PVA) and cellulosic nanostructures are favorable for active food packaging applications. The current study systematically investigates the mechanical properties, gas permeation, and swelling parameters of PVA composites with cellulose nanocrystals (CNC) or nano lignocellulose (NLC) fibers. Alterations in these macroscopic properties, which are critical for food packaging applications, are correlated with structural information at the molecular level. Strong interactions between the fillers and polymer host matrix were observed, while the PVA crystallinity exhibited a maximum at ~1% loading. Finally, the orientation of the PVA nanocrystals in the uniaxially stretched samples was found to depend non-monotonically on the CNC loading and draw ratio. Concerning the macroscopic properties of the composites, the swelling properties were reduced for the D1 food simulant, while for water, a considerable decrease was observed only when high NLC loadings were involved. Furthermore, although the water vapor transmission rates are roughly similar for all samples, the CO₂, N₂, and O₂ gas permeabilities are low, exhibiting further decrease in the 1% and 1–5% loading for CNC and NLC composites, respectively. The mechanical properties were considerably altered as a consequence of the good dispersion of the filler, increased crystallinity of the polymer matrix, and morphology of the filler. Thus, up to ~50%/~170% enhancement of the Young’s modulus and up to ~20%/~50% enhancement of the tensile strength are observed for the CNC/NLC composites. Interestingly, the elongation at break is also increased by ~20% for CNC composites, while it is reduced by ~40% for the NLC composites, signifying the favorable/unfavorable interactions of cellulose/lignin with the matrix. Full article

(This article belongs to the Special Issue Cellulose and Its Composites: Preparation and Applications)

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18 pages, 5009 KB

Open AccessEditor’s ChoiceArticle

Preparation of Glass Fiber Reinforced Polypropylene Bending Plate and Its Long-Term Performance Exposed in Alkaline Solution Environment

by Zhan Peng, Anji Wang, Chen Wang and Chenggao Li

Polymers 2025, 17(13), 1844; https://doi.org/10.3390/polym17131844 - 30 Jun 2025

Viewed by 1133

Abstract

Glass fiber reinforced polypropylene composite plates have gradually attracted more attention because of their repeated molding, higher toughness, higher durability, and fatigue resistance compared to glass fiber reinforced thermosetting composites. In practical engineering applications, composite plates have to undergo bending effect at different [...] Read more.

Glass fiber reinforced polypropylene composite plates have gradually attracted more attention because of their repeated molding, higher toughness, higher durability, and fatigue resistance compared to glass fiber reinforced thermosetting composites. In practical engineering applications, composite plates have to undergo bending effect at different angles in corrosive environment of concrete, including bending bars from 0~90°, and stirrups of 90°, which may lead to long-term performance degradation. Therefore, it is important to evaluate the long-term performance of glass fiber reinforced polypropylene composite bending plates in an alkali environment. In the current paper, a new bending device is developed to prepare glass fiber reinforced polypropylene bending plates with the bending angles of 60° and 90°. It should be pointed out that the above two bending angles are simulated typical bending bars and stirrups, respectively. The plate is immersed in the alkali solution environment for up to 90 days for long-term exposure. Mechanical properties (tensile properties and shear properties), thermal properties (dynamic mechanical properties and thermogravimetric analysis) and micro-morphology analysis (surface morphology analysis) were systematically designed to evaluate the influence mechanism of bending angle and alkali solution immersion on the long-term mechanical properties. The results show the bending effect leads to the continuous failure of fibers, and the outer fibers break under tension, and the inner fibers buckle under compression, resulting in debonding of the fiber–matrix interface. Alkali solution (OH⁻ ions) corrode the surface of glass fiber to form soluble silicate, which is proved by the mass fraction of glass fiber decreased obviously from 79.9% to 73.65% from thermogravimetric analysis. This contributes to the highest degradation ratio of tensile strength was 71.6% (60° bending) and 65.6% (90° bending), respectively, compared to the plate with bending angles of 0°. A high curvature bending angle (such as 90°) leads to local buckling of fibers and plastic deformation of the matrix, forming microcracks and fiber–resin interface bonding at the bending area, which accelerates the chemical erosion and debonding process in the interface area, bringing about an additional maximum 10.56% degradation rate of the shear strength. In addition, the alkali immersion leads to the obvious degradation of storage modulus and thermal decomposition temperature of composite plate. Compared with the other works on the long-term mechanical properties of glass fiber reinforced polypropylene, it can be found that the long-term performance of glass fiber reinforced polypropylene composites is controlled by the corrosive media type, bending angle and immersion time. The research results will provide durability data for glass fiber reinforced polypropylene composites used in concrete as stirrups. Full article

(This article belongs to the Section Polymer Composites and Nanocomposites)

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33 pages, 11174 KB

Open AccessEditor’s ChoiceReview

Photopolymer Flexographic Printing Plate Mold for PDMS Microfluidic Manufacture

by Ana Belén Peñaherrera-Pazmiño, Gustavo Iván Rosero, Maximiliano Pérez and Betiana Lerner

Polymers 2025, 17(13), 1723; https://doi.org/10.3390/polym17131723 - 20 Jun 2025

Cited by 1 | Viewed by 2863

Abstract

Flexographic printing, traditionally used in the packaging industry, has emerged as a promising technology for microfluidic device fabrication due to enabling high resolution and being commercially available at a low cost compared to conventional techniques. This review explores the adaptation of a photopolymer [...] Read more.

Flexographic printing, traditionally used in the packaging industry, has emerged as a promising technology for microfluidic device fabrication due to enabling high resolution and being commercially available at a low cost compared to conventional techniques. This review explores the adaptation of a photopolymer flexographic printing plate mold (FMold) for microfluidics, examining its advantages, challenges, and applications. It offers a state-of-the-art view of the application of FMold for microfluidic systems, which offers a unique opportunity in terms of cost-effectiveness, scalability, and rapid prototyping. Applications are diverse: FMold has enabled the fabrication of microfluidic devices used in enhanced oil recovery to prepare rock-on-a-chip models, droplet generation and storage, suspension cell culture, monoclonal antibody production, complex cell differentiation pattern creation, phage screening, drug screening, cell detection, and cancer stem cell culture. Since its first appearance in 2018, FMold has been utilized in 50 publications in different laboratories around the world. Key advancements, current research trends, and future prospects are discussed to provide a comprehensive overview of this evolving tool. Full article

(This article belongs to the Special Issue Advances in Functional Polymer Materials for Biomedical Applications)

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17 pages, 3390 KB

Open AccessEditor’s ChoiceArticle

Controlled Formation of Au Nanonetworks via Discrete BTA-Oligo(Acrylic Acid)₃ Supramolecular Templates

by Sadaf Aiman, Soonyoung Choi, Hyosun Lee, Sang-Ho Lee and Eunyong Seo

Polymers 2025, 17(12), 1662; https://doi.org/10.3390/polym17121662 - 15 Jun 2025

Viewed by 1005

Abstract

Precise control over molecular dispersity and supramolecular assembly is essential for designing nanostructures with targeted properties and functionalities. In this study, we explore the impact of molecular dispersity in BTA-oligo(AA)₃ oligomers on the formation and structural organization of Au nanomaterials in an [...] Read more.

Precise control over molecular dispersity and supramolecular assembly is essential for designing nanostructures with targeted properties and functionalities. In this study, we explore the impact of molecular dispersity in BTA-oligo(AA)₃ oligomers on the formation and structural organization of Au nanomaterials in an aqueous system. Discrete and polydisperse BTA-oligo(AA)₃ samples are systematically synthesized and characterized to evaluate their role as templates for nanostructure formation. UV-vis spectroscopy and TEM analyses reveal distinct differences in the resulting nanostructures. Specifically, discrete oligomers facilitate the formation of well-defined, interconnected Au nanonetworks with high structural uniformity, even at elevated concentrations. In contrast, polydisperse oligomers facilitated the formation of isolated Au nanoparticles with limited control over morphology and connectivity. These differences are attributed to the greater molecular uniformity and enhanced self-assembly capabilities of the discrete oligomers, which serve as effective templates for directing Au precursor organization and reduction into ordered nanostructures. This study provides mechanistic insight into how molecular dispersity affects the templating and assembly of gold nanomaterials. The findings offer a promising strategy for developing tailored nanostructures with interconnected morphologies and controlled optical and structural properties, paving the way for advanced applications. Full article

(This article belongs to the Special Issue Advanced Polymer Structures: Chemistry for Engineering Applications)

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18 pages, 8613 KB

Open AccessEditor’s ChoiceReview

Sensitive Chemical and Biological Sensors Based on Phosphorus Dendrimers

by Anne-Marie Caminade

Polymers 2025, 17(12), 1591; https://doi.org/10.3390/polym17121591 - 6 Jun 2025

Cited by 1 | Viewed by 1401

Abstract

Dendrimers are a special type of ball-shaped hyperbranched polymers consisting of branched monomers organized stepwise around a multifunctional core. They possess many reactive functions, and they are easily accessible as they are located on the surface of the dendrimers. By modifying their terminal [...] Read more.

Dendrimers are a special type of ball-shaped hyperbranched polymers consisting of branched monomers organized stepwise around a multifunctional core. They possess many reactive functions, and they are easily accessible as they are located on the surface of the dendrimers. By modifying their terminal functions, it is possible to change the specificities of dendrimers to give them the desired properties. Dendrimers have been used as catalysts, in diverse fields of nanomedicine, and for the elaboration or modification of materials. The internal structure of dendrimers should be carefully chosen depending on the sought-after properties. Poly(phosphorhydrazone) (PPH) dendrimers possess a relatively rigid and hydrophobic internal structure and an easily functionalized surface, which make them appealing in the field of materials. Indeed, they can be used as a matrix, as glue for stabilizing multilayers, or as multifunctional tools. This review describes the use of PPH dendrimers and dendrons (dendritic wedges) for elaborating sensitive chemical, electrochemical, and biological sensors. Full article

(This article belongs to the Special Issue Development of Applications of Polymer-Based Sensors and Actuators)

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14 pages, 1694 KB

Open AccessEditor’s ChoiceArticle

An Assessment of Anion Exchange Membranes for CO₂ Capture Processes: A Focus on Fumasep^® and Sustainion^®

by Kseniya Papchenko, Sandra Kentish and Maria Grazia De Angelis

Polymers 2025, 17(11), 1581; https://doi.org/10.3390/polym17111581 - 5 Jun 2025

Viewed by 2481

Abstract

Anion exchange membranes are utilised in cutting-edge energy technologies including electrolysers and fuel cells. Recently, these membranes have also emerged as a promising tool in CO₂ capture techniques, such as moisture-driven direct air capture and the separation of CO₂ from other [...] Read more.

Anion exchange membranes are utilised in cutting-edge energy technologies including electrolysers and fuel cells. Recently, these membranes have also emerged as a promising tool in CO₂ capture techniques, such as moisture-driven direct air capture and the separation of CO₂ from other gases, leveraging the moisture-induced sorption/desorption and diffusion of CO₂ in its ionic forms. In this study, we examine the absorption and permeation of CO₂ and CH₄ in two commercially available anion exchange membranes, Fumasep^® and Sustainion^®, under dry conditions. With the exception of CO₂ sorption in Fumasep^®, these measurements have not been previously reported. These new data points are crucial for evaluating the fundamental separation capabilities of these materials and for devising innovative CO₂ capture strategies, as well as for the simulation of novel combined processes. In a dry state, both materials demonstrate similar CO₂ absorption levels, with a higher value for Sustainion^®. The CO₂ solubility coefficient decreases with pressure, as is typical for glassy polymers. Fumasep^® exhibits higher CO₂/CH₄ ideal solubility selectivity, equal to ~10 at sub-ambient pressures, and higher diffusivity. The CO₂ diffusion coefficient increases with the CO₂ concentration in both membranes due to swelling of the matrix, varying between 0.7 and 2.2 × 10⁻⁸ cm²/s for Fumasep^® and between 1.6 and 9.0 × 10⁻⁹ cm²/s for Sustainion^®. CO₂ permeability exhibits a minimum at a pressure of approximately 2–3 bar. The CO₂ permeability in the dry state is higher in Fumasep^® than in Sustainion^®: 3.43 and 0.72 Barrer at a 2-bar transmembrane pressure, respectively. The estimated perm-selectivity was found to reach values of up to 40 at sub-ambient pressures. The CO₂ permeability and CO₂/CH₄ estimated perm-selectivity in both polymers are of a similar order of magnitude to those measured in fluorinated ion exchange membranes such as Nafion^®. Full article

(This article belongs to the Special Issue Recent Trends in Polymer Membranes: Fabrication Technique, Characterization, Functionalization, and Applications in Environmental Science, 2nd Edition)

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13 pages, 2036 KB

Open AccessEditor’s ChoiceArticle

Oxidative Decomposition of Poly(phenylene sulfide) Composites Under Fast Elevation of Temperature

by Aurélie Bourdet, Yann Carpier, Eric Dargent, Benoit Vieille and Nicolas Delpouve

Polymers 2025, 17(11), 1560; https://doi.org/10.3390/polym17111560 - 3 Jun 2025

Cited by 1 | Viewed by 2003

Abstract

The thermal resistance of carbon fiber–reinforced poly(phenylene sulfide) to harsh oxidative conditions is investigated through thermogravimetric experiments performed in an oxygen atmosphere. While these materials usually show great resistance against thermal decomposition in a nitrogen atmosphere, the experiments in oxygen reveal the total [...] Read more.

The thermal resistance of carbon fiber–reinforced poly(phenylene sulfide) to harsh oxidative conditions is investigated through thermogravimetric experiments performed in an oxygen atmosphere. While these materials usually show great resistance against thermal decomposition in a nitrogen atmosphere, the experiments in oxygen reveal the total decomposition of both the matrix and the carbon fibers. The Gram–Schmidt signal, obtained by coupling thermogravimetric analysis in standard conditions with Fourier-transform infrared spectroscopy, exhibits multiple events, evidencing that the decomposition proceeds through distinct stages. The first step characterizes the char formation, while the second relates to its oxidative decomposition. A third step, only observed for composites, is interpreted as the signature of the oxidative decomposition of carbon fibers. To mimic the sudden elevation of temperature encountered during a fire, the analyses are performed at rates of up to 500 K min⁻¹. These specific experimental conditions reveal a complex dependence of the thermogravimetric signature on the heating rate. Independent of the atmosphere, nitrogen or oxygen, the characteristic temperature of decomposition follows a bell-shape trend, resulting from the combination of lag effects and thermal-conductivity limitations. Additionally, the increase of the heating rate causes the Gram–Schmidt signal to evolve toward a broad peak with indistinct events. To investigate whether these changes affect the decomposition products, the infrared spectra, continuously recorded to probe the whole decomposition, are compared with those from the database. The char formation is characterized by the production of sulfur dioxide, while carbon dioxide is the main product emitted during both char and fiber oxidative decomposition. Owing to the merging of the decomposition stages, sulfur-dioxide detection is partly supplanted by that of carbon dioxide under fast elevations of temperature. Full article

(This article belongs to the Special Issue Advances in the Thermal Characterization of Polymers and Plastic Waste)

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11 pages, 1479 KB

Open AccessEditor’s ChoiceArticle

Cashmere Blended with Calcium Alginate Fibers: Eco-Friendly Improvement of Flame Retardancy and Maintenance of Hygroscopicity

by Yujie Cai, Zewen Li, Bin Wang, Chao Xu, Xing Tian and Fengyu Quan

Polymers 2025, 17(11), 1497; https://doi.org/10.3390/polym17111497 - 28 May 2025

Cited by 1 | Viewed by 1189

Abstract

As a natural fiber, cashmere is favored for its softness, finesse, and warmth. However, its poor flame-retardant properties seriously affect the safety of cashmere. Current flame-retardant treatments for cashmere tend to lead to heavy metal pollution and significantly reduce wearer comfort. In this [...] Read more.

As a natural fiber, cashmere is favored for its softness, finesse, and warmth. However, its poor flame-retardant properties seriously affect the safety of cashmere. Current flame-retardant treatments for cashmere tend to lead to heavy metal pollution and significantly reduce wearer comfort. In this work, natural and environmentally friendly calcium alginate fibers were blended with cashmere to obtain blended fibers. The blended fibers exhibited good hygroscopicity and softness. The incorporation of calcium alginate fibers enhanced the flame retardancy of the blends, and the LOI of the blended fibers reached 40.2 without smoldering. It was due to a stable CaO protective layer formed by Ca²⁺ during combustion and the dense carbon layer with the decomposition intermediates of cashmere, which exerted a flame-retardant effect in the condensed phase. This study provided an eco-friendly approach to producing high-quality flame-retardant cashmere products. Full article

(This article belongs to the Special Issue Environmentally Friendly Textiles, Fibers and Their Composites)

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23 pages, 1540 KB

Open AccessEditor’s ChoiceArticle

Polymeric Membrane Contactors for CO₂ Separation: A Systematic Literature Analysis of the Impact of Absorbent Temperature

by Edoardo Magnone, Min Chang Shin and Jung Hoon Park

Polymers 2025, 17(10), 1387; https://doi.org/10.3390/polym17101387 - 18 May 2025

Viewed by 1155

Abstract

Global warming, driven significantly by carbon dioxide (CO₂) emissions, necessitates immediate climate action. Consequently, CO₂ capture is essential for mitigating carbon output from industrial and power generation processes. This study investigates the effect of absorbent temperature on CO₂ separation [...] Read more.

Global warming, driven significantly by carbon dioxide (CO₂) emissions, necessitates immediate climate action. Consequently, CO₂ capture is essential for mitigating carbon output from industrial and power generation processes. This study investigates the effect of absorbent temperature on CO₂ separation performance using gas–liquid polymeric hollow fiber membrane (HFM) contactors. It summarizes the relationship between liquid-phase temperature and CO₂ capture efficiency across various physical and chemical absorption processes. Twelve relevant studies (nine experimental, three mathematical), providing a comprehensive database of 104 individual measurements, were rigorously analyzed. Liquid-phase temperature significantly influences CO₂ separation performance in HFM contactors. In particular, the present analysis reveals that, overall, for every 10 °C temperature increase, physical absorption performance decreases by approximately 3%, while chemical absorption performance improves by 3%, regardless of other parameters. This empirical law was confirmed by direct comparisons with additional experimental results. Strategies for further development of these processes are also proposed. Full article

(This article belongs to the Special Issue Polymer Materials for Environmental Applications)

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16 pages, 10309 KB

Open AccessEditor’s ChoiceArticle

Chemical Recycling of PLA and Its Copolyesters with Poly(Ethylene Azelate) via Microwave-Assisted Alkaline Hydrolysis and Enzymatic Hydrolysis

by Rafail O. Ioannidis, Nikolaos D. Bikiaris, Evangelia Vouvoudi, Alexandra Zamboulis, Nikolaos Nikolaidis and Dimitrios N. Bikiaris

Polymers 2025, 17(10), 1374; https://doi.org/10.3390/polym17101374 - 16 May 2025

Cited by 4 | Viewed by 2921

Abstract

Poly(lactic acid) (PLA) is a widely used biobased polyester which can be derived from renewable resources. Due to its excellent properties, it has already been adopted in various industrial sectors. While PLA is compostable, its degradation to the environment is very slow, necessitating [...] Read more.

Poly(lactic acid) (PLA) is a widely used biobased polyester which can be derived from renewable resources. Due to its excellent properties, it has already been adopted in various industrial sectors. While PLA is compostable, its degradation to the environment is very slow, necessitating the development of efficient recycling methods. This study focuses on the chemical recycling via microwave-assisted alkaline hydrolysis of PLA and its copolymers with poly(ethylene azelate) (PEAz), aiming to recover both carboxylic acid monomers: lactic acid and azelaic acid. Moreover, our method tunes the degradation of PLA via the synthesis of the novel aliphatic PLA-based copolyesters, targeting engineering-like applications, specifically in the field of printed electronics. Various process parameters were analyzed, including the temperature and the duration of the experiments as well as different phase transfer catalysts. Complete degradation was achieved at low temperatures (110–125 °C) and short times (12–15 min) for the PLA-based copolyesters, offering significant environmental benefits, as considerably less energy is consumed compared to chemical conventional methods. So, by changing the composition of the copolyesters through the incorporation of PEAz blocky segments, the ester bonds became more susceptible to hydrolysis under alkaline conditions assisted with microwave irradiation. Additionally, enzymatic hydrolysis was also studied in parallel for comparative purposes, revealing low degradation rates, thus establishing the microwave-assisted alkaline hydrolysis as a solid and reliable method for tuning the degradation of PLA-based materials. Full article

(This article belongs to the Special Issue Advances in the Thermal Characterization of Polymers and Plastic Waste)

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17 pages, 9487 KB

Open AccessEditor’s ChoiceArticle

Polymer Composite Sandwich Panels Composed of Hemp and Plastic Skins and Composite Wood, Recycled Plastic, and Styrofoam Cores

by Ashiqul Islam, Wahid Ferdous, Paulomi (Polly) Burey, Kamrun Nahar, Libo Yan and Allan Manalo

Polymers 2025, 17(10), 1359; https://doi.org/10.3390/polym17101359 - 15 May 2025

Cited by 2 | Viewed by 2112

Abstract

This paper presents an experimental investigation of six different types of composite sandwich panels manufactured from waste-based materials, which are comprised of two different types of skins (made from hemp and recycled PET (Polyethylene terephthalate) fabrics with bio-epoxy resin) and three different cores [...] Read more.

This paper presents an experimental investigation of six different types of composite sandwich panels manufactured from waste-based materials, which are comprised of two different types of skins (made from hemp and recycled PET (Polyethylene terephthalate) fabrics with bio-epoxy resin) and three different cores (composite wood, recycled plastic, and styrofoam) materials. The skins of these sandwich panels were investigated under five different environmental conditions (normal air, water, hygrothermal, saline solution, and 80 °C elevated temperature) over seven months to evaluate their durability performance. In addition, the tensile and dynamic mechanical properties of those sandwich panels were studied. The bending behavior of cores and sandwich panels was also investigated and compared. The results indicated that elevated temperatures are 30% more detrimental to fiber composite laminates than normal water. Composite laminates made of hemp are more sensitive to environmental conditions than composite laminates made of recycled PET. A higher-density core makes panels more rigid and less susceptible to indentation failure. The flexible plastic cores are found to be up to 25% more effective at increasing the strength of sandwich panels than brittle wood cores. Full article

(This article belongs to the Special Issue Sustainable Polymeric Materials in Building and Construction)

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20 pages, 4862 KB

Open AccessEditor’s ChoiceArticle

Fabrication of PVDF Membranes with a PVA Layer for the Effective Removal of Volatile Organic Compounds in Semiconductor Wastewater

by Youngmin Choi and Changwoo Nam

Polymers 2025, 17(10), 1332; https://doi.org/10.3390/polym17101332 - 14 May 2025

Cited by 6 | Viewed by 2551

Abstract

Through the application of advanced membrane modification strategies, high-performance membranes have been developed to effectively remove organic contaminants such as toluene and xylene from wastewater. These membranes demonstrate superior antifouling resistance and long-term operational stability, offering a competitive advantage for semiconductor wastewater treatment. [...] Read more.

Through the application of advanced membrane modification strategies, high-performance membranes have been developed to effectively remove organic contaminants such as toluene and xylene from wastewater. These membranes demonstrate superior antifouling resistance and long-term operational stability, offering a competitive advantage for semiconductor wastewater treatment. This study introduces a novel approach to membrane fabrication using polyvinylidene fluoride (PVDF), recognized for its cost-effectiveness and distinct antifouling properties in contaminant removal. To enhance the performance of the membrane, the solvent (DMA, DMF, NMP) that dissolves PVDF and the immersion time (30 min, 60 min, 90 min) at which phase separation occurs were identified. Additionally, the membranes were treated with polyvinyl alcohol (PVA) through multiple dip coatings to enhance their hydrophilicity before a comparative analysis was conducted. The resulting optimized membranes demonstrated high emulsion fluxes (4412

L m^{- 2} h^{- 1} {bar}^{- 1}

for toluene) and achieved oil-removal efficiencies exceeding 90% when tested with various organic solvents, including toluene, cyclohexane, xylene, benzene, and chloroform. The resulting optimized membranes prove to be a reliable means of producing clean water and of efficiently separating organic contaminants from wastewater. Showcasing remarkable antifouling capabilities and suitability for repeated use without significant efficiency loss, this solution effectively addresses cost and fouling challenges, presenting it as a sustainable and efficient wastewater treatment method for the semiconductor industry. Full article

(This article belongs to the Special Issue Advanced Polymers for Wastewater Treatment and Toxicant Removal, 2nd Edition)

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19 pages, 6080 KB

Open AccessEditor’s ChoiceReview

Current Status and Future Trends for Modification Technology of Flame Retardant Nylon 66

by Bingtao Feng, Senlong Yu, Hengxue Xiang, Lili Li and Meifang Zhu

Polymers 2025, 17(8), 1074; https://doi.org/10.3390/polym17081074 - 16 Apr 2025

Cited by 7 | Viewed by 3275

Abstract

Nylon 66 (PA66) has been widely used in automotive, electronics, textiles and other fields due to its excellent mechanical properties, chemical corrosion resistance and thermal stability. However, the fire hazard caused by its flammability severely limits its further application in high–end and high–risk [...] Read more.

Nylon 66 (PA66) has been widely used in automotive, electronics, textiles and other fields due to its excellent mechanical properties, chemical corrosion resistance and thermal stability. However, the fire hazard caused by its flammability severely limits its further application in high–end and high–risk fields. Therefore, improving the flame retardancy of PA66 to enhance its safety has become the focus of current research. This review aims to better understand the research status and development trends of flame retardant PA66. Firstly, the combustion process and flame retardant mechanism of PA66 were described. Secondly, the latest research progress of flame retardant PA66 was comprehensively reviewed, including blending, copolymerization and post–finishing flame retardant modification methods. Meanwhile, the research status of blending flame retardant PA66 was emphatically introduced, and the advantages and disadvantages of different additive flame retardants were analyzed. Finally, the future development direction of flame retardant PA66 is proposed, which provides an important reference for its follow-up study. Full article

(This article belongs to the Special Issue Polymer Manufacturing Processes)

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