Polymers

20 pages, 4782 KB

Open AccessArticle

Porous Organosilica Films: Is It Possible to Enhance Hydrophobicity While Maintaining Elastic Stiffness?

by Alexey S. Vishnevskiy, Dmitry A. Vorotyntsev, Dmitry S. Seregin, Konstantin A. Vorotilov and Alexander S. Sigov

Polymers 2025, 17(17), 2433; https://doi.org/10.3390/polym17172433 - 8 Sep 2025

Abstract

Organosilica films, composed of a silicon oxide network with terminal methyl groups, are widely utilized in various applications, including microelectronics. Many of these applications require high hydrophobicity and good mechanical properties, which pose a significant challenge because the Si–CH₃ groups disrupt the [...] Read more.

Organosilica films, composed of a silicon oxide network with terminal methyl groups, are widely utilized in various applications, including microelectronics. Many of these applications require high hydrophobicity and good mechanical properties, which pose a significant challenge because the Si–CH₃ groups disrupt the Si–O–Si network. This issue becomes particularly pronounced in porous films. Here, we investigate whether material properties can be tuned by simply altering the spatial arrangement of methyl groups. To achieve this, we prepared copolymer films with one or two methyl groups bonded to a silicon atom, while maintaining a constant total amount of methyl groups. The films were deposited using a sol–gel technique combined with template self-assembly. The precursor content was varied to compare films with different proportions of Si–CH₃ and Si(–CH₃)₂. Film characterization included FTIR, ellipsometric porosimetry, AFM, and WCA measurements and dielectric constant evaluations. Our findings indicate that precursors containing dimethyl groups enhance the connectivity of the Si–O–Si network, resulting in a higher Young’s modulus and smaller pore size compared to films with an equivalent amount of methyl groups. However, the lower thermal stability of dimethyl bonds limits the thermal budget of these films. Thus, the spatial arrangement of organic groups within the polymer structure can be employed to tune material properties. These results expand the understanding of organic–inorganic hybrid materials and offer novel approaches for their applications. Full article

(This article belongs to the Special Issue Silicon-Based Polymers: From Synthesis to Applications)

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31 pages, 2951 KB

Open AccessArticle

Mechanical, Durability, and Environmental Impact Properties of Natural and Recycled Fiber Geopolymer with Zero Waste Approach: Alternative to Traditional Building Materials

by Haluk Görkem Alcan

Polymers 2025, 17(17), 2432; https://doi.org/10.3390/polym17172432 - 8 Sep 2025

Abstract

This study evaluates the physical, mechanical, durability, and environmental properties of geopolymer mortars (GMs) produced using waste tire steel fibers (WTSFs), hemp fibers (HFs), waste marble powder (WMP), and recycled fine aggregates (RFAs). Within the scope of this study, fibers were incorporated as [...] Read more.

This study evaluates the physical, mechanical, durability, and environmental properties of geopolymer mortars (GMs) produced using waste tire steel fibers (WTSFs), hemp fibers (HFs), waste marble powder (WMP), and recycled fine aggregates (RFAs). Within the scope of this study, fibers were incorporated as single and hybrid types at 0.5% and 1% by volume. The addition of HFs generally reduced dry unit weight, as well as compressive and flexural strength but increased fracture energy by nearly three times. The addition of WTSFs improved compressive and flexural strengths by up to 42% and enhanced fracture energy by 840%. Hybrid fibers increased the strength values by 21% and the fracture energy by up to four times, demonstrating a clear synergistic effect between HFs and WTSFs in enhancing crack resistance and structural stability. In the durability tests conducted within the scope of this study, HFs burnt at 600 °C, while WTSFs showed signs of corrosion under freeze–thaw and acid conditions; however, hybrid fibers combined the benefits of both materials, resulting in an effective preservation of internal structure. The fact that the materials used in the production of GM samples were waste or recycled products reduced the total cost to 188 USD/m³, and thanks to these materials and the carbon-negative properties of HFs, CO₂ emissions were reduced to 338 kg CO₂/m³. The presented study demonstrates the potential of using recycled and waste materials to create sustainable building materials in the construction industry. Full article

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

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15 pages, 1249 KB

Open AccessArticle

Investigation of the Variants of Independent Elastic Constants of Rigid Polyurethane Foams with Symmetry Elements

by Aivars Lagzdiņš, Ilze Beverte, Vilis Skruls and Jānis Andersons

Polymers 2025, 17(17), 2431; https://doi.org/10.3390/polym17172431 - 8 Sep 2025

Abstract

Rigid PU foams have wide practical applications, and their mathematical modelling would benefit from deeper knowledge about the variants of independent elastic constants of symmetric PU foams. Therefore, in this study, various symmetry elements of rigid PU foams were analysed in relation to [...] Read more.

Rigid PU foams have wide practical applications, and their mathematical modelling would benefit from deeper knowledge about the variants of independent elastic constants of symmetric PU foams. Therefore, in this study, various symmetry elements of rigid PU foams were analysed in relation to the characteristics of production moulds and technologies. The generalised Hooke’s law was considered together with additional relationships valid for certain types of symmetry. Variants of independent elastic constants were determined for orthotropic, orthotropic with a rotational symmetry, and isotropic PU foams. For transtropic PU foams, nine variants of independent elastic constants were identified and corresponding equations for the components of response strain tensor were derived. Then, in order to investigate the results provided by the 9 variants, 12 elastic constants were determined experimentally in compression and shear for free-rise, rigid, and quasi-transtropic PU foams with average densities of 34 kg/m³, 55 kg/m³, and 75 kg/m³. Based on the analysis of (a) measurement uncertainties and (b) satisfying of the transtropy equations, an assessment was made of the correspondence of the experimentally determined elastic constants to the constants of a perfectly transtropic material. This made it possible to identify variants of independent constants that ensure the best correspondence between the calculated strains and the set of average strains. Full article

(This article belongs to the Special Issue Advances in the Preparation, Properties and Application of Polyurethane, Cellulose and Their Composites (3rd Edition))

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24 pages, 10004 KB

Open AccessArticle

Deposition-Induced Thermo-Mechanical Strain Behaviour of Magnetite-Filled PLA Filament in Fused Filament Fabrication Under Varying Printing Conditions

by Boubakeur Mecheri and Sofiane Guessasma

Polymers 2025, 17(17), 2430; https://doi.org/10.3390/polym17172430 - 8 Sep 2025

Abstract

Residual stresses and internal strains in 3D printing can lead to issues such as cracking, warping, and delamination—challenges that are amplified when using functional composite materials like magnetic PLA filaments. This study investigates the thermo-mechanical strain evolution during fused filament fabrication (FFF) of [...] Read more.

Residual stresses and internal strains in 3D printing can lead to issues such as cracking, warping, and delamination—challenges that are amplified when using functional composite materials like magnetic PLA filaments. This study investigates the thermo-mechanical strain evolution during fused filament fabrication (FFF) of magnetite-filled PLA using an integrated methodology combining strain gauge sensors, high-resolution infrared thermal imaging, and synchrotron X-ray microtomography. Printing parameters, including nozzle temperature (190–220 °C), build platform temperature (30–100 °C), printing speed (30–60 mm/s), and cooling strategy (fan on/off) were systematically varied to evaluate their influence. Results reveal steep thermal gradients along the build direction (up to −1 °C/µm), residual strain magnitudes reaching 0.1 µε, and enhanced viscoelastic creep at elevated platform temperatures. The addition of magnetic particles modifies heat distribution and strain evolution, leading to strong sensitivity to process conditions. These findings provide valuable insight into the complex thermo-mechanical interactions governing the structural integrity of magnetically functionalized PLA composites in additive manufacturing. Full article

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15 pages, 818 KB

Open AccessArticle

Screening of Wood Raw Materials for Low-Odor Fiberboard and Particleboard Production: Analysis and Evaluation Based on Volatile Odor Compounds

by Bo Liu, Fang Yang, Lina Tang, Xianwu Zou, Liming Zhu, Qian Chen, Bin Lv and Yuejin Fu

Polymers 2025, 17(17), 2429; https://doi.org/10.3390/polym17172429 - 8 Sep 2025

Abstract

Woody raw materials of wood-based panels like fiberboard and particleboard are one of the primary sources of product odor and one of the indicators affecting the comprehensive health risk assessment of wood-based panel products. This study employed Gas Chromatography-Mass Spectrometry-Olfactometry (GC-MS-O) to investigate [...] Read more.

Woody raw materials of wood-based panels like fiberboard and particleboard are one of the primary sources of product odor and one of the indicators affecting the comprehensive health risk assessment of wood-based panel products. This study employed Gas Chromatography-Mass Spectrometry-Olfactometry (GC-MS-O) to investigate the odorant composition and odor characteristics, including Total Odor Concentration (TOC), odor intensity (OI), odor activity value (OAV), and risk value (RV), of 22 wood species commonly used in fiberboard and particleboard production in China. This research identified the major odor-active compounds in wood and provided recommendations for selecting wood raw materials suitable for low-odor fiberboards and particleboards produced by integrating RV and toxicity classification data. The results showed that the main compound types influencing wood odor in 22 wood species were predominantly terpenes, aldehydes, and alcohols. Woods of Cinnamomum, Machilus, and Pinus contained a higher number of dominant odor compounds (OAV > 1 and OI ≥ 3). Wood with stronger odor intensity included Cinnamomum, Pinus, Machilus, Bischofia, and Saurauia. The total RV of Cinnamomum, Pinus, Machilus, Cunninghamia, and Bombax wood exceeded one, necessitating special attention when used as raw materials for wood-based panels. Camphor in Cinnamomum and Machilus wood was the most concentrated odorant, followed by 3-Carene in Pinus wood. Odorants with high OAV included Longifolene, δ-Cadinene, Terpinen-4-ol, 2-Nonenal, γ-Terpinene, d-Limonene, 3-methyl-Butanal, Octanal, α-Pinene, Hexanal, D-Camphor, and trans-Calamenene. Odorants with high RV included terpenes, alcohols, aldehydes, and ketones, such as Camphor, 3-Carene, Eucalyptol, α-Terpineol, β-Pinene, α-Santalene, δ-Cadinene, Safrole, Longifolene, and d-Limonene. Focusing on the reduction and control of these odor-active compounds represents a primary approach to mitigating odors in fiberboard and particleboard products. However, addressing health risks associated with product odors requires additional attention to four specific substances: Safrole, Camphor, Eucalyptol, and α-Terpineol. Although the total RV for the five wood species exceeds one, this does not necessarily mean the final wood-based panel product’s RV exceeds one, as it also depends on the influence of the production process. Therefore, further research should be conducted to investigate the effects of various process parameters in wood-based panel production on the odor compounds present in the final panels. From a comprehensive perspective, considering the overall odor characteristics of wood volatiles, all 18 wood species (Salix, Populus, Rhaphiolepis, Ligustrum, Prunus, Fagus, Pterocarya, Firmiana, Celtis, Cunninghamia, Bombax, Bischofia, Ficus, Saurauia, Eucalyptus, Aleurites, Melia, Bridelia) are suitable for the production of low-odor fiberboards and particleboards. Full article

(This article belongs to the Special Issue Eco-Friendly Supramolecular Polymeric Materials, 2nd Edition)

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27 pages, 11310 KB

Open AccessArticle

Functionalisation Effects on Mechanical, Electrical and Thermal Properties of 3D-Printed MWCNT/ABS Nanocomposites

by Nima Zohdi, Phan Quoc Khang Nguyen, Yixia (Sarah) Zhang and Richard (Chunhui) Yang

Polymers 2025, 17(17), 2428; https://doi.org/10.3390/polym17172428 - 8 Sep 2025

Abstract

While fused filament fabrication (FFF) has gained widespread popularity in additive manufacturing, its prevalent limitation in mechanical properties has prompted researchers to explore innovative solutions, with the creation of nanocomposites emerging as a promising solution. In this study, the effect of multi-walled carbon [...] Read more.

While fused filament fabrication (FFF) has gained widespread popularity in additive manufacturing, its prevalent limitation in mechanical properties has prompted researchers to explore innovative solutions, with the creation of nanocomposites emerging as a promising solution. In this study, the effect of multi-walled carbon nanotubes (MWCNTs) on the material properties and morphology of acrylonitrile butadiene styrene (ABS)-based nanocomposites at various MWCNT concentrations of 0.1–1.5% is investigated. A 0.5% MWCNT addition was found to be the optimal content for mechanical, electrical, and thermal properties for FFF-printed specimens printed at longitudinal and transverse build orientations with profound improvement compared to pure ABS. Morphological analysis confirms the significant influence of air voids, low interlayer bonding and the agglomeration of additives on the properties of FFF-printed parts. Then, functionalisation methods are developed in this study for the effective modification of nanoadditives, and their influences on mechanical, electrical and thermal properties of FFF-printed nanocomposite parts are investigated. Both the covalent and non-covalent methods of functionalisation result in a uniform dispersion of nanoadditives with a positive impact on the material properties of those parts, especially for those printed at transverse build orientations. Full article

(This article belongs to the Special Issue New Progress of Polymeric Materials in Advanced Manufacturing, 2nd Edition)

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33 pages, 4874 KB

Open AccessReview

Rheology Modifying Reagents for Clay-Rich Mineral Suspensions: A Review

by Williams Leiva, Norman Toro, Pedro Robles, Gonzalo R. Quezada, Iván Salazar, Javier Flores-Badillo and Ricardo I. Jeldres

Polymers 2025, 17(17), 2427; https://doi.org/10.3390/polym17172427 - 8 Sep 2025

Viewed by 82

Abstract

In the mining industry, key unit operations such as grinding, flotation, thickening, and tailings transport are negatively affected by the presence of clay minerals, which impart complex rheological behaviors to mineral suspensions by increasing their rheological properties. This deterioration arises from specific physicochemical [...] Read more.

In the mining industry, key unit operations such as grinding, flotation, thickening, and tailings transport are negatively affected by the presence of clay minerals, which impart complex rheological behaviors to mineral suspensions by increasing their rheological properties. This deterioration arises from specific physicochemical characteristics of clay minerals such as fine particle size, anisotropic character, laminar morphology, and swelling capacity. This work reviews the effects of various rheology-modifying reagents on clay suspensions including kaolinite, illite, and montmorillonite. The reviewed reagents include inorganic salts, pH modifiers, polymers, surfactants, and nanoparticles. Their mechanisms of interaction with solid particles are analyzed, highlighting their influence on the degree of dispersion or aggregation. Furthermore, this review proposes research opportunities focused on the formulation of hybrid reagents, modified biopolymers, and the development of reagents effective under adverse conditions such as high salinity or elevated temperatures. This review provides a comprehensive basis for optimizing the use of rheological additives through more efficient and sustainable strategies for managing clay-rich suspensions in the mining industry. Full article

(This article belongs to the Special Issue Synthesis and Processing of Functional Polymer Materials–2nd Edition)

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34 pages, 19025 KB

Open AccessArticle

Development of Filaments for 3D Printing from Poly(Lactic Acid) Polymeric Nanocomposites and Carbon Nanotubes

by Sanches Ismael de Oliveira, João Carlos Martins da Costa, Nayra Reis do Nascimento, Gilberto Garcia del Pino, José Luis Valin Rivera, Meylí Valin Fernández and José Costa de Macedo Neto

Polymers 2025, 17(17), 2426; https://doi.org/10.3390/polym17172426 - 8 Sep 2025

Viewed by 105

Abstract

The aim of this study is to obtain poly(lactic acid) polymeric nanocomposites and carbon nanotubes for application in drone propellers produced through 3D printing. In this work, a filament based on poly(lactic acid)—PLA/functionalized carbon nanotube (CNT) composites was prepared for the fused deposition [...] Read more.

The aim of this study is to obtain poly(lactic acid) polymeric nanocomposites and carbon nanotubes for application in drone propellers produced through 3D printing. In this work, a filament based on poly(lactic acid)—PLA/functionalized carbon nanotube (CNT) composites was prepared for the fused deposition modeling (FDM) process. The effects of CNT content (0.2–1.0%), temperature variation, and extruder screw rotation variation were applied in the Design of Experiments (DOE) tool, where the main factors contributing to filament quality, focusing on mechanical strength, were identified. Through this tool, an optimum point for the material’s mechanical strength was reached, showing a value of 48.87 MPa, 43.17% above the initial value of 27.77 MPa. The response surface curve revealed a region where new filaments with similar mechanical strength values to those found in this work could be obtained. The results demonstrate that CNT content, extruder screw rotation, and extruder temperature directly influence filament quality. The data obtained from Thermogravimetry (TG) and Derivative Thermogravimetry (DTG) curves show that the addition of 0.6% CNT by weight does not significantly modify PLA degradation resistance, despite slight differences in temperatures. The main reason for these alterations is the dispersion of CNTs in the PLA matrix and CNT agglomeration. Through the demonstrated simulation, it is possible to confirm the application of the developed material in drone propeller manufacturing, facilitating access and providing new opportunities for users. Full article

(This article belongs to the Section Polymer Processing and Engineering)

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27 pages, 4764 KB

Open AccessArticle

Development and Characterization of PVA/KGM-Based Bioactive Films Incorporating Natural Extracts and Thyme Oil

by Ayşenur Yeşilyurt

Polymers 2025, 17(17), 2425; https://doi.org/10.3390/polym17172425 - 8 Sep 2025

Viewed by 333

Abstract

This study focused on the development and characterization of polyvinyl alcohol (PVA)- and konjac glucomannan (KGM)-based composite films enriched with natural bioactive additives. A PK (PVA/KGM) matrix with the optimum tensile strength was selected, and five film formulations were prepared by incorporating Aronia [...] Read more.

This study focused on the development and characterization of polyvinyl alcohol (PVA)- and konjac glucomannan (KGM)-based composite films enriched with natural bioactive additives. A PK (PVA/KGM) matrix with the optimum tensile strength was selected, and five film formulations were prepared by incorporating Aronia melanocarpa extract (AME), red dragon fruit extract (DFE), and thyme essential oil (TEO). TEO was also introduced via a Pickering emulsion (PE) technique. The total phenolic content (TPC) and free radical scavenging activity (FRSA) of extracts and films were determined, where AME exhibited the highest antioxidant activity (TPC: 243 mg GAE/g; FRSA: 81.7%). The additive-free PK film displayed limited antioxidant activity (18%), while antioxidant capacity significantly improved with extract and EO incorporation. The PK-A film (AME-added) demonstrated the highest tensile strength and lowest water vapor permeability, supported by increased local crystallinity detected in XRD. Color analysis indicated dominant red-violet tones in AME films and greenish-yellow tones in DFE films. FTIR confirmed that no new chemical bonds were formed between active compounds and the polymer matrix. DSC thermograms revealed consistent melting peaks (~150 °C) for all films, while Tg varied from 37 to 73 °C depending on additive type, reflecting plasticization effects of extracts and the counterbalancing effect of essential oil. The most hydrophobic (76.8°) and opaque sample was PK-ADO, prepared via the PE technique. Overall, natural extracts improved the structural, thermal, barrier, and antioxidant properties of PK films. Full article

(This article belongs to the Special Issue Functionalized Bio-Based Polymers for Environmental Applications)

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14 pages, 3103 KB

Open AccessArticle

Engineering Thermo-Responsive Hydrogels with Tailored Mechanics for Biomedical Integration

by Sungmo Choi, Minkyeong Pyo, Sangmin Lee, Yunseo Jeong, Yuri Nam, Seonghyeon Park, Yoon-A Jang, Kisung Kim and Chan Ho Park

Polymers 2025, 17(17), 2424; https://doi.org/10.3390/polym17172424 - 8 Sep 2025

Viewed by 303

Abstract

Poly(N-isopropylacrylamide) (PNIPAAm) hydrogels exhibit temperature-responsive volume changes near physiological temperature, but their low mechanical strength in the swollen state limits use in structurally demanding biomedical applications. In this study, we systematically investigated poly(NIPAAm-co-acrylamide), P(NIPAAm-co-AAm), hydrogels with varying AAm-to-NIPAAm ratios to explore the compositional [...] Read more.

Poly(N-isopropylacrylamide) (PNIPAAm) hydrogels exhibit temperature-responsive volume changes near physiological temperature, but their low mechanical strength in the swollen state limits use in structurally demanding biomedical applications. In this study, we systematically investigated poly(NIPAAm-co-acrylamide), P(NIPAAm-co-AAm), hydrogels with varying AAm-to-NIPAAm ratios to explore the compositional trade-offs between thermal responsiveness and mechanical performance. Hydrogels were synthesized under fixed crosslinker and water content conditions, and evaluated through compressive mechanical testing, thermal swelling analysis, and crosslinking density estimation. Our results show that increasing AAm content enhances mechanical strength and stiffness but reduces the magnitude of temperature-induced volumetric shrinkage. An intermediate comonomer formulation demonstrated an optimal balance, maintaining both sufficient mechanical integrity for transdermal microneedle insertion and a reversible volume transition. This study highlights the potential of compositional tuning in hydrogel systems to meet the competing demands of responsiveness and durability in advanced biomedical applications. Full article

(This article belongs to the Special Issue Smart Polymeric Materials for Biomedical Applications)

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22 pages, 5057 KB

Open AccessArticle

Analysis of the Applicability of Accelerated Conditioning Protocols in Concrete Beams Reinforced with Steel and GFRP: Effects of Chloride Exposure

by Amanda Duarte Escobal Mazzú and Gláucia Maria Dalfré

Polymers 2025, 17(17), 2423; https://doi.org/10.3390/polym17172423 - 7 Sep 2025

Viewed by 254

Abstract

The durability of Fiber-Reinforced Polymer (FRP) bars is typically evaluated using accelerated conditioning protocols (ACP), which are applied to bar samples, either directly exposed or embedded in small concrete specimens, under aggressive environmental conditions. Thus, this study investigates the applicability of the ACPs [...] Read more.

The durability of Fiber-Reinforced Polymer (FRP) bars is typically evaluated using accelerated conditioning protocols (ACP), which are applied to bar samples, either directly exposed or embedded in small concrete specimens, under aggressive environmental conditions. Thus, this study investigates the applicability of the ACPs recommended by ACI440.9R (2015), from the American Concrete Institute, to assess the potential effects of chloride exposure on reinforced concrete beams. Twelve beams—six reinforced with steel and six with Glass Fiber-Reinforced Polymer (GFRP)—were tested under two scenarios: (1) a reference condition, with beams stored for 1000 h in a controlled laboratory environment, and (2) a conditioned condition, where beams were immersed in a 3.5% NaCl solution at 50 ± 3 °C for 1000 h prior to beam casting. After, the beams were evaluated through three-point bending tests, focusing on load–deflection behavior, failure modes, crack patterns, and strain distribution in concrete and reinforcement. The results indicated that chloride exposure adversely affected both steel and GFRP-reinforced beams. Steel-reinforced concrete beams exhibited a 12% reduction in load-bearing capacity due to steel corrosion, while the GFRP-reinforced concrete beams showed a 10% reduction in load-bearing capacity due to water absorption by the GFRP. Full article

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

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13 pages, 1756 KB

Open AccessArticle

Methylcellulose-Encapsulated Magnesium-Substituted Biphasic Calcium Phosphate Granules for Local Drug Delivery in Bone Tissue Engineering: Modification for Prolonged Release and Antibacterial Behavior

by Daniil O. Golubchikov, Inna V. Fadeeva, Elena S. Trofimchuk, Katia Barbaro, Viktoriya G. Yankova, Iulian V. Antoniac, Valery I. Putlayev, Julietta V. Rau and Vicentiu Saceleanu

Polymers 2025, 17(17), 2422; https://doi.org/10.3390/polym17172422 - 7 Sep 2025

Viewed by 318

Abstract

Bone tissue restoration requires biomaterials, which combine osteoinductivity and the capability to prevent surgical site infections. Magnesium-substituted biphasic calcium phosphate (Mg-BCP) represents a promising solution, as magnesium substitution increases the biodegradation rate of calcium phosphate ceramics and provides inherent antibacterial properties. This study [...] Read more.

Bone tissue restoration requires biomaterials, which combine osteoinductivity and the capability to prevent surgical site infections. Magnesium-substituted biphasic calcium phosphate (Mg-BCP) represents a promising solution, as magnesium substitution increases the biodegradation rate of calcium phosphate ceramics and provides inherent antibacterial properties. This study aimed to achieve wet precipitation synthesis of magnesium-substituted (1–10 mol%) biphasic calcium phosphate and to evaluate its drug delivery potential and antibacterial performance. Porous Mg-BCP granules were fabricated via the gelation of Mg-BCP suspension in sodium alginate followed by polymer removal. Drug delivery potential was evaluated using methylene blue as a model compound, with methylcellulose encapsulation implemented to ensure prolonged release. Magnesium content directly ruled the phase composition: low concentrations (1%) favored hydroxyapatite phase prevalence, while higher concentrations led to the β-tricalcium phosphate formation. Further assessment of drug delivery potential revealed that direct drug loading resulted in burst release, whereas methylcellulose encapsulation successfully enabled prolonged drug delivery. Mg-5BCP formulation demonstrated significant antimicrobial activity with growth inhibition of 17.7 ± 4.1% against C. albicans, 20.8 ± 7.0% against E. faecalis, and 12.9 ± 7.5% against E. coli. Therefore, Mg-5BCP–methylcellulose composite granules present a versatile platform for antibacterial drug delivery for bone tissue engineering applications. Full article

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

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14 pages, 1295 KB

Open AccessArticle

Determination of Odor Compounds in Lignocellulose-Based Panels Using DHS-GC/MS Combined with Odor Activity Value Analysis

by Lina Tang, Qian Chen, Liming Zhu, Xiaorui Liu, Xianwu Zou, Yuejin Fu and Bo Liu

Polymers 2025, 17(17), 2421; https://doi.org/10.3390/polym17172421 - 6 Sep 2025

Viewed by 318

Abstract

Wood, as the oldest natural polymer composite material on Earth, holds significant importance in the era of carbon neutrality and serves as an irreplaceable core material in the furniture and construction industries. As a primary raw material for furniture, wood-based lignocellulosic boards have [...] Read more.

Wood, as the oldest natural polymer composite material on Earth, holds significant importance in the era of carbon neutrality and serves as an irreplaceable core material in the furniture and construction industries. As a primary raw material for furniture, wood-based lignocellulosic boards have drawn increasing consumer attention due to their odor characteristics. In order to achieve the determination of odor compounds in lignocellulose-based panels, this study established a method combining dynamic headspace sampling (DHS), gas chromatography–mass spectrometry (GC–MS), and odor activity value (OAV) analysis. To address the wide concentration range of odor compounds in lignocellulose-based panels, a three-level standard curve was established to meet the detection of odor substances in common lignocellulose-based panels. The favorable conditions for each factor were as follows: sheet-shaped samples, TENAX-TA adsorbent, 20 mL headspace vials, and a split ratio of 25:1. The method demonstrated good linearity within the range of 0.002–15 mg/m³, with recovery rates ranging from 94.74% to 103.44%. The method was applied to analyze commercially available particleboard, fiberboard, and plywood. A total of 33 odor components were detected. The results indicated that aldehyde contributed significantly to the odor of particleboard, acids were the main contributors to the odor of fiberboard, and terpenes dominated the odor of plywood. The established method is suitable for the qualitative and quantitative analysis of odor compounds in lignocellulose-based panels and provides reliable technical support for tracing, identifying, and controlling odors in these materials. Full article

(This article belongs to the Special Issue Eco-Friendly Supramolecular Polymeric Materials, 2nd Edition)

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18 pages, 21787 KB

Open AccessArticle

Influence of Bio-Based Infill Materials on the Fire Resistance of Panelised Timber Wall Assemblies—A Pilot Study

by Ľudmila Tereňová, Zuzana Vidholdová and Ľubomír Valigurský

Polymers 2025, 17(17), 2420; https://doi.org/10.3390/polym17172420 - 6 Sep 2025

Viewed by 339

Abstract

In the pursuit of low-impact and renewable construction materials, various by-products from agriculture, forestry, and the wood processing industry are being explored as potential bio-based infill materials for wall assemblies. This study presents an experimental assessment of the fire performance of timber wall [...] Read more.

In the pursuit of low-impact and renewable construction materials, various by-products from agriculture, forestry, and the wood processing industry are being explored as potential bio-based infill materials for wall assemblies. This study presents an experimental assessment of the fire performance of timber wall systems composed of block units filled with different lignocellulosic materials, subjected to radiative heat exposure. These assemblies are representative of external walls in contemporary timber-framed buildings. Two configurations were examined: one with sawdust infill and the other with wood pellet infill. Both samples were exposed to radiant heat from the interior side for 60 min, simulating conditions of a fully developed compartment fire. The applied heat flux was 20 kW·m⁻², delivered by a calibrated radiant panel. The results indicate that even minor design variations—particularly the choice of infill material—can significantly influence the thermal response, degradation kinetics of wood-based components, and the overall fire resistance of the wall assembly. The sawdust-filled system exhibited superior performance, achieving an estimated fire resistance rating of 60 min (60 REI). It showed reduced internal thermal degradation compared to the pellet-filled variant, which experienced greater charring depth due to internal voids between pellets, although it maintained structural integrity. Full article

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

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4 pages, 158 KB

Open AccessEditorial

Recent Advances and Future Directions in Thermal, Electrical, and Mechanical Properties of Polymer Composites

by Gabriel Pinto, Victoria Alcázar and Marina P. Arrieta

Polymers 2025, 17(17), 2419; https://doi.org/10.3390/polym17172419 - 6 Sep 2025

Viewed by 368

Abstract

Polymer composites continue to redefine the boundaries of what materials can achieve [...] Full article

(This article belongs to the Special Issue Advances in Thermal, Electrical and Mechanical Properties of Polymer Composites)

20 pages, 2070 KB

Open AccessFeature PaperArticle

Effect of Water Regeneration and Integration on Technical Indicators of PVC Manufacturing Using Process System Engineering

by Eduardo Andrés Aguilar-Vásquez, Segundo Rojas-Flores and Ángel Darío González-Delgado

Polymers 2025, 17(17), 2418; https://doi.org/10.3390/polym17172418 - 6 Sep 2025

Viewed by 427

Abstract

The suspension polymerization process of polyvinyl chloride (PVC) production involves significant freshwater consumption alongside substantial wastewater emissions. Mass integration strategies have been used to address this problem, but only through direct recycling approaches. Therefore, in this study, a regeneration approach was applied to [...] Read more.

The suspension polymerization process of polyvinyl chloride (PVC) production involves significant freshwater consumption alongside substantial wastewater emissions. Mass integration strategies have been used to address this problem, but only through direct recycling approaches. Therefore, in this study, a regeneration approach was applied to integrate a PVC suspension process to improve water management. The reuse network was evaluated through a water–energy–product (WEP) technical analysis after being simulated in AspenPlus software v.14. The mass integration allowed for a 61% reduction in freshwater consumption and an 83% reduction in wastewater. However, 258.6 t/day of residual wastewater still remained after regeneration. The WEP analysis found that the process was efficient in handling raw materials and process products due to the high yield and recovery of unreacted materials. Similarly, the integration significantly benefitted the process performance as water usage indicators improved substantially, with freshwater consumption of 83%, a wastewater production rate of 63%, and freshwater water costs of $267,322 per year (from $694,080 before integration). In terms of energy performance, the results were regular. The processes showed high energy consumption (below 50%), with indicators related to the use of natural gas, electricity, and energy costs being affected by the regeneration. However, the limited heat integration provided minor energy savings (11 MJ/h). Finally, this work gives an interesting insight into water conservation and the circular economy, since the study used the latest systems in regeneration of effluents for plastic plants (emerging technologies), showcasing important benefits and trade-offs of these strategies. Full article

(This article belongs to the Special Issue Biodegradable and Functional Polymers for Food Packaging)

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20 pages, 5176 KB

Open AccessArticle

Experimental Study on the Bending Behaviour of GFRP Laminates Repaired with Stainless-Steel Wire Mesh

by Hamza Taş and Hasan Yavuz Ünal

Polymers 2025, 17(17), 2417; https://doi.org/10.3390/polym17172417 - 5 Sep 2025

Viewed by 407

Abstract

This study experimentally investigates the use of stainless-steel woven wire mesh (SSWWM) as a patch material for repairing damaged glass fibre-reinforced (GFR) composite laminates. The effects of several factors on the three-point bending (3PB) behaviour of the parent laminate were examined, including the [...] Read more.

This study experimentally investigates the use of stainless-steel woven wire mesh (SSWWM) as a patch material for repairing damaged glass fibre-reinforced (GFR) composite laminates. The effects of several factors on the three-point bending (3PB) behaviour of the parent laminate were examined, including the repair method (the plugging of open hole and the external patch repair), the mesh count of the SSWWM, and the number of SSWWM layers. According to the findings, all parameters considered in this study play a pivotal role in 3PB behaviour. Employing SSWWM as a patch material can recover 66.02–129.2% of the undamaged 3PB failure load, depending on the repair method, mesh count of the SSWWM, and number of SSWWM layers. Overall, decreasing the mesh count and increasing the number of SSWWM layers and applying an external patch repair method yield better results in terms of failure load and patch efficiency. This can be attributed to the increased wire diameter, improved bending rigidity, and better load distribution over a wider area. The SSWWM bridges the damaged zone, ensuring effective load transfer between the patch and parent laminate while preventing crack propagation. Utilising SSWWM as a patch material provides a quick, reliable solution for damage scenarios in engineering applications. Full article

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

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25 pages, 8643 KB

Open AccessArticle

2D to 3D Modification of Chang–Chang Criterion Considering Multiaxial Coupling Effects in Fiber and Inter-Fiber Directions for Continuous Fiber-Reinforced Composites

by Yingchi Chen, Junhua Guo and Wantao Guo

Polymers 2025, 17(17), 2416; https://doi.org/10.3390/polym17172416 - 5 Sep 2025

Viewed by 372

Abstract

Fiber-reinforced composites are widely used in aerospace and other fields due to their excellent specific strength, specific stiffness, and corrosion resistance, and further study of their failure criteria is essential to improve the accuracy and reliability of failure behavior prediction under complex loads. [...] Read more.

Fiber-reinforced composites are widely used in aerospace and other fields due to their excellent specific strength, specific stiffness, and corrosion resistance, and further study of their failure criteria is essential to improve the accuracy and reliability of failure behavior prediction under complex loads. There are still some limitations in the current composite failure criterion research, mainly reflected in the lack of promotion of three-dimensional stress state, lack of sufficient consideration of multi-modal coupling effects, and the applicability of the criteria under multiaxial stress and complex loading conditions, which limit the wider application of composites in the leading-edge fields to a certain degree. In this work, a generalized Mohr failure envelope function approach is adopted to obtain the stress on the failure surface as a power series form of independent variable, and the unknown coefficients are determined according to the damage conditions, to extend the Chang–Chang criterion to the three-dimensional stress state, and to consider the coupling effect between the fiber and matrix failure modes. The modified Chang–Chang criterion significantly enhances the failure prediction accuracy of composite materials under complex stress states, especially in the range of multi-axial loading and small off-axis angles, which provides a more reliable theoretical basis and practical guidance for the safe design and performance optimization of composite structures in aerospace and other engineering fields. Full article

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

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16 pages, 16095 KB

Open AccessArticle

Mechanistic Insights into the Non-Monotonic Flame Retardancy of CPVC/ABS Composite

by Long Zhang, Lewen Liu, Shengwen Zou, Peng Qin, Zhengzhu Zhu, Shaoyun Guo and Qining Ke

Polymers 2025, 17(17), 2415; https://doi.org/10.3390/polym17172415 - 5 Sep 2025

Viewed by 429

Abstract

The chlorinated polyvinyl chloride (CPVC)/acrylonitrile–butadiene–styrene (ABS) composite represents an important class of engineering thermoplastics, offering a strong balance of flame retardancy, chemical resistance, mechanical properties, processability, and cost efficiency. Despite its widespread application, the flame-retardant mechanism in the CPVC/ABS system remains poorly understood. [...] Read more.

The chlorinated polyvinyl chloride (CPVC)/acrylonitrile–butadiene–styrene (ABS) composite represents an important class of engineering thermoplastics, offering a strong balance of flame retardancy, chemical resistance, mechanical properties, processability, and cost efficiency. Despite its widespread application, the flame-retardant mechanism in the CPVC/ABS system remains poorly understood. This work systematically investigated the non-monotonic flame-retardant behavior of CPVC/ABS composites through comprehensive characterization. The combustion performance, as determined by limiting oxygen index (LOI), UL-94 vertical burning tests, and cone calorimeter tests (CCTs), showed an unexpected pattern of flame retardancy initially improving then decreasing with reduced ABS content, which contradicted conventional expectations. The optimal composition at a CPVC/ABS ratio of 2:3 demonstrated good performance, achieving a UL-94 5VA rating and 47.3% reduction in total heat release (THR) relative to CPVC. A more stable and compact structure was observed from the morphology analysis of the residual char, and the thermogravimetric analysis further revealed a synergistic effect in carbonization behavior. The above flame-retardant mechanism could be interpreted by the combined effects of accelerated char formation during the early decomposition stage and significantly enhanced char crosslinking degree. These findings provided fundamental insights for designing high-performance flame-retardant polymer composites and facilitating their industrial implementation. Full article

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

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15 pages, 8341 KB

Open AccessArticle

Design, Synthesis, and Characterization of a Novel Tetra-Block Copolymer for High-Performance Self-Healing Batteries

by Işık İpek Avcı Yayla, Omer Suat Taskin and Neslihan Yuca

Polymers 2025, 17(17), 2414; https://doi.org/10.3390/polym17172414 - 5 Sep 2025

Viewed by 456

Abstract

Lithium-ion batteries (LIBs) have become the dominant energy storage technology due to their versatility and superior performance across diverse applications. Silicon (Si) stands out as a particularly promising high-capacity anode material for next-generation LIBs, offering a theoretical capacity nearly ten times greater than [...] Read more.

Lithium-ion batteries (LIBs) have become the dominant energy storage technology due to their versatility and superior performance across diverse applications. Silicon (Si) stands out as a particularly promising high-capacity anode material for next-generation LIBs, offering a theoretical capacity nearly ten times greater than conventional graphite anodes. However, its practical implementation faces a critical challenge: the material undergoes a ~300% volume expansion during lithiation/delithiation, which causes severe mechanical stress, electrode pulverization, and rapid capacity decay. In addressing these limitations, advanced polymer binders serve as essential components for preserving the structural integrity of Si-based anodes. Notably, self-healing polymeric binders have emerged as a groundbreaking solution, capable of autonomously repairing cycle-induced damage and significantly enhancing electrode durability. The evaluation of self-healing performance is generally based on mechanical characterization methods while morphological observations by scanning electron microscopy provide direct evidence of crack closure; for electrochemically active materials, electrochemical techniques including GCD, EIS, and CV are employed to monitor recovery of functionality. In this study, a novel self-healing copolymer (PHX-23) was synthesized for Si anodes using a combination of octadecyl acrylate (ODA), methacrylic acid (MA), 2-hydroxyethyl methacrylate (HEMA), and polyethylene glycol methyl ether methacrylate (PEGMA). The copolymer was thoroughly characterized using NMR, FTIR, TGA, SEM, and EDX to confirm its chemical structure, thermal stability, and morphology. Electrochemical evaluation revealed that the PHX-23 binder markedly improves cycling stability, sustaining a reversible capacity of 427 mAh g⁻¹ after 1000 cycles at 1C. During long-term cycling, the Coulombic efficiency of the PHX-23 polymer is 99.7%, and similar functional binders in the literature have shown similar results at lower C-rates. Comparative analysis with conventional binders (e.g., PVDF and CMC/SBR) demonstrated PHX-23’s exceptional performance, exhibiting higher capacity retention and improved rate capability. These results position PHX-23 as a transformative binder for silicon anodes in next-generation lithium-ion batteries. Full article

(This article belongs to the Special Issue Smart Polymers and Composites in Multifunctional Systems)

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19 pages, 3126 KB

Open AccessArticle

Performance Enhancement of Lightweight PLA Parts Printed by FFF Using Taguchi–GRA Method

by Oğuz Tunçel and Çağlar Kahya

Polymers 2025, 17(17), 2413; https://doi.org/10.3390/polym17172413 - 5 Sep 2025

Viewed by 448

Abstract

Lightweight PLA (LW-PLA) filaments enable material-saving designs in fused filament fabrication (FFF), yet optimizing their mechanical performance remains challenging due to temperature-sensitive foaming behavior. This study aims to enhance the structural strength and material efficiency of LW-PLA parts using a multi-objective statistical approach. [...] Read more.

Lightweight PLA (LW-PLA) filaments enable material-saving designs in fused filament fabrication (FFF), yet optimizing their mechanical performance remains challenging due to temperature-sensitive foaming behavior. This study aims to enhance the structural strength and material efficiency of LW-PLA parts using a multi-objective statistical approach. Four key process parameters—infill density (Id), material flow rate (Mf), wall line count (Wlc), and infill pattern (Ip)—were systematically varied using a Taguchi L₁₆ orthogonal array. Tensile strength (Ts), flexural strength (Fs), and material consumption (Mc) were selected as the critical response metrics. Grey Relational Analysis (GRA) was used to aggregate these responses into a single performance index, and ANOVA determined each factor’s contribution. The optimal combination of 60% infill density, 70% material flow, 4 wall lines, and line infill pattern yielded a 9.02% improvement in the overall performance index compared to the baseline, with corresponding Ts and Fs values of 13.58 MPa and 20.51 MPa. Mf and Wlc were the most influential parameters on mechanical behavior, while Id mainly affected Mc. These findings confirm that integrating Taguchi and GRA enables effective parameter tuning for LW-PLA, balancing strength and efficiency. This work contributes to the development of lightweight, high-performance parts suitable for functional applications such as UAVs and prototyping. Full article

(This article belongs to the Special Issue Multiscale and Multi-Physical Behavior of Polymers and Polymer Composites)

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30 pages, 12288 KB

Open AccessArticle

Experimental Investigation of Four-Point Bending Test Results of GFRP and CFRP Composites Used in Wind Turbine Blades

by Senai Yalçinkaya, Mehmet Fatih Yoldaş and Dudu Mertgenç Yoldaş

Polymers 2025, 17(17), 2412; https://doi.org/10.3390/polym17172412 - 5 Sep 2025

Viewed by 487

Abstract

The depletion of fossil fuels and the rise of environmental concerns have increased the importance of renewable energy sources, positioning wind energy as a key alternative. Modern wind turbine blades are predominantly manufactured from composite materials due to their light weight, high strength, [...] Read more.

The depletion of fossil fuels and the rise of environmental concerns have increased the importance of renewable energy sources, positioning wind energy as a key alternative. Modern wind turbine blades are predominantly manufactured from composite materials due to their light weight, high strength, and resistance to corrosion. In offshore applications, approximately 95% of the composite content is glass fiber-reinforced polymer (GFRP), while the remaining 5% is carbon fiber-reinforced polymer (CFRP). GFRP is favored for its low cost and fatigue resistance, whereas CFRP offers superior strength and stiffness but is limited by high production costs. This study investigates the durability of adhesively bonded GFRP and CFRP joints under marine exposure. Seven-layer GFRP and eight-layer CFRP laminates were produced using a 90° unidirectional twill weave and prepared in accordance with ASTM D5868-01. Specimens were immersed in natural Aegean Sea water (21 °C, salinity 3.3–3.7%) for 1, 2, and 3 months. Measurements revealed that GFRP absorbed significantly more moisture (1.02%, 2.97%, 3.78%) than CFRP (0.49%, 0.76%, 0.91%). Four-point bending tests conducted according to ASTM D790 showed reductions in Young’s modulus of up to 9.45% for GFRP and 3.48% for CFRP. Scanning electron microscopy (SEM) confirmed that moisture-induced degradation was more severe in GFRP joints compared to CFRP. These findings highlight the critical role of environmental exposure in the mechanical performance of marine composite joints. Full article

(This article belongs to the Special Issue Advanced Manufacturing and Multifunctional Applications of Fiber-Reinforced Polymer Composites)

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19 pages, 2463 KB

Open AccessArticle

Development of an SA/XLG Composite Hydrogel Film for Customized Facial Mask Applications

by Su-Mei Huang, Xu-Ling Sun, Chia-Ching Li and Jiunn-Jer Hwang

Polymers 2025, 17(17), 2410; https://doi.org/10.3390/polym17172410 - 5 Sep 2025

Viewed by 510

Abstract

This study aims to address the poor extensibility, brittleness, and limited hydration stability of pure sodium alginate (SA) hydrogels, which hinder their use in flexible, skin-adherent applications such as facial masks, by developing bio-based composites incorporating five representative functional additives: xanthan gum, guar [...] Read more.

This study aims to address the poor extensibility, brittleness, and limited hydration stability of pure sodium alginate (SA) hydrogels, which hinder their use in flexible, skin-adherent applications such as facial masks, by developing bio-based composites incorporating five representative functional additives: xanthan gum, guar gum, hydroxyethyl cellulose (HEC), poly(ethylene glycol)-240/hexamethylene diisocyanate copolymer bis-decyl tetradeceth-20 ether (GT-700), and Laponite^® XLG. Composite hydrogels were prepared by blending 1.5 wt% SA with 0.3 wt% of each additive in aqueous humectant solution, followed by ionic crosslinking using 3% (w/w) CaCl₂ solution. Physicochemical characterization included rotational viscometry, uniaxial tensile testing, ATR-FTIR spectroscopy, swelling ratio analysis, and pH measurement. Among them, the SA/XLG composite exhibited the most favorable performance, showing the highest viscosity, shear-thickening behavior, and markedly enhanced extensibility with an elongation at break of 14.8% (compared to 2.5% for neat SA). It also demonstrated a mean swelling ratio of 0.24 g/g and complete dissolution in water within one year. ATR-FTIR confirmed distinct non-covalent interactions between SA and XLG without covalent modification. The hydrogel also demonstrated excellent conformability to complex 3D surfaces, consistent hydration retention under centrifugal stress (+23.6% mass gain), and complete biodegradability in aqueous environments. Although its moderately alkaline pH (8.96) may require buffering for dermatological compatibility, its mechanical resilience and environmental responsiveness support its application as a sustainable, single-use skin-contact material. Notably, the SA/XLG composite hydrogel demonstrated compatibility with personalized fabrication strategies integrating 3D scanning and additive manufacturing, wherein facial topography is digitized and transformed into anatomically matched molds—highlighting its potential for customized cosmetic and biomedical applications. Full article

(This article belongs to the Special Issue Stimuli-Responsive Polymers: Advances and Prospects)

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17 pages, 4085 KB

Open AccessArticle

Magneto-Tunable Surface Roughness and Hydrophobicity of Magnetoactive Elastomers Based on Polymer Networks with Different Architectures

by Sobit E. Kirgizov, Sergey A. Kostrov and Elena Yu. Kramarenko

Polymers 2025, 17(17), 2411; https://doi.org/10.3390/polym17172411 - 4 Sep 2025

Viewed by 426

Abstract

In this study, we present experimental investigations of the surface structure and water contact angles of magnetoactive elastomers (MAEs), which are controlled by an external magnetic field. Specifically, we examine how the polymer matrix architecture affects the surface roughness and wettability of MAEs [...] Read more.

In this study, we present experimental investigations of the surface structure and water contact angles of magnetoactive elastomers (MAEs), which are controlled by an external magnetic field. Specifically, we examine how the polymer matrix architecture affects the surface roughness and wettability of MAEs in various magnetic fields. We performed a comparative analysis on MAEs based on a linear polysiloxane network and on a matrix of the same chemical nature containing side-grafted chains. We synthesized a series of magnetoactive elastomers containing 75 wt.% carbonyl iron and varying amounts of a low-molecular-weight plasticizer. Although the magnetorheological effect is higher for traditional linear MAEs, we found that the magnetic response in surface properties is higher for novel MAEs with side-grafted chains. The largest increase in water contact angle was observed in the side-chain MAEs with the highest 60 wt.% plasticizer content: rising from 112° in a zero field to 168° in a 490 mT magnetic field. Water contact angles exhibit greater stability over time for side-chain MAEs, and this stability further increases in the presence of a magnetic field. Our results demonstrate that the architecture of the polymer matrix serves as an effective tool for designing smart, magnetically responsive surfaces. Full article

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

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18 pages, 5466 KB

Open AccessArticle

Fabrication of Zein Nanoparticle-Functionalized Wheat Gluten Amyloid Fibril/Methyl Cellulose Hybrid Membranes with Efficient Performance for Water-in-Oil Emulsion Separation

by You-Ren Lai, Jun-Ying Lin, Jou-Ting Hsu, Ta-Hsien Lin, Su-Chun How and Steven S.-S. Wang

Polymers 2025, 17(17), 2409; https://doi.org/10.3390/polym17172409 - 4 Sep 2025

Viewed by 437

Abstract

Considering the high stability of water-in-oil (W/O) emulsions, contamination from emulsified pollutants poses a long-term risk to the environment. In this study, hybrid membranes composed of wheat gluten amyloid fibrils (WGAFs) and zein nanoparticles (ZNPs) were prepared and used as a separator to [...] Read more.

Considering the high stability of water-in-oil (W/O) emulsions, contamination from emulsified pollutants poses a long-term risk to the environment. In this study, hybrid membranes composed of wheat gluten amyloid fibrils (WGAFs) and zein nanoparticles (ZNPs) were prepared and used as a separator to remove emulsified W/O droplets from the oily phase. ZNPs and WGAFs were synthesized through antisolvent method and fibrillation process. Next, a ZNP-functionalized wheat gluten AF/methyl cellulose (ZNP-WGAF/MC) hybrid membrane was fabricated, and its properties were investigated via various analytical techniques. Lastly, the separation efficiency of the ZNP-WGAF/MC hybrid membrane for various W/O emulsions was assessed using microscopy and light scattering. The formation of ZNPs or WGAFs was first verified via spectroscopic and microscopic methods. Our results indicated that the ZNP-WGAF/MC hybrid membranes were synthesized via chemical crosslinking coupled with the casting method. Furthermore, the incorporation of either WGAFs or ZNPs was found to improve the thermal stability and surface hydrophobicity of membranes. Finally, the separation efficiency of the ZNP-WGAF/MC hybrid membranes for various W/O emulsions was determined to be ~87–99%. This research demonstrates the potential of harnessing three-dimensional membranes composed of plant protein-based fibrils and nanoparticles to separate emulsified W/O mixtures. Full article

(This article belongs to the Special Issue Functional Polymer Membranes for Advanced Separation Technologies)

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30 pages, 26752 KB

Open AccessReview

Advances and Applications of Bionic Design and Functional Integration in Underwater Soft Grippers

by Chaoqun Xiang, Hongsen Sun, Teng Wu, Ye Chen, Yanjie Wang and Tao Zou

Polymers 2025, 17(17), 2408; https://doi.org/10.3390/polym17172408 - 4 Sep 2025

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Abstract

This paper systematically reviews the research progress of underwater soft grasping devices in the field of bionic structure, function integration, and tactile sensing technology by drawing on the structural characteristics of marine organisms such as octopuses, jellyfish, and sea anemones (such as suction [...] Read more.

This paper systematically reviews the research progress of underwater soft grasping devices in the field of bionic structure, function integration, and tactile sensing technology by drawing on the structural characteristics of marine organisms such as octopuses, jellyfish, and sea anemones (such as suction cups, umbrella-like muscles, and stinging cells). This paper analyzes the inspiration for the design, the application of innovative materials, and the integration of sensing and driving from marine organisms, including a review of soft robotics technologies, such as shape memory alloys (SMA), ionic polymer metal composite materials (IPMCs), magnetic nanocomposite cilia, etc. The research results emphasize that bionic soft robots have the potential for transformation in completely changing underwater operations by providing enhanced flexibility, efficiency, and environmental adaptability. This work provides a bionic design paradigm and perception-driven integration method for underwater soft operation systems, thereby promoting equipment innovation in the fields of deep-sea exploration and ecological protection. Full article

(This article belongs to the Special Issue Advancing Soft Robotics with Polymers)

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20 pages, 5274 KB

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Numerical Investigations of the Seam Opening Behavior of Peelable Seal Seams as a Function of the Seal Seam Formation

by Marc Götz, Fabian Kayatz and Marek Hauptmann

Polymers 2025, 17(17), 2407; https://doi.org/10.3390/polym17172407 - 4 Sep 2025

Viewed by 462

Abstract

In the process of heat contact sealing of thin, flexible polymer films, the choice of the film material, the layer structure, the sealing tools, and the process parameters influence the melt flow. A pronounced melt flow dynamic, which is to be expected in [...] Read more.

In the process of heat contact sealing of thin, flexible polymer films, the choice of the film material, the layer structure, the sealing tools, and the process parameters influence the melt flow. A pronounced melt flow dynamic, which is to be expected in industrial applications due to the high temperatures and pressures, favors the formation of sealing edges that negatively affect the user-friendliness when opening the packaging. In this study, the influence of seal seam formation on the opening behavior was systematically investigated by numerical simulation. A detailed model was developed that simulates the seam opening process, accounting for the composite structure, the detailed geometry of the seal seam, and the separation process. The numerical results of the force-offset behavior showed good agreement with experimental data. Parameter studies revealed that the thicker and more pronounced seal seams lead to higher tear-off forces, while thinner and less pronounced seams result in lower forces. These findings provide valuable insights into the interactions between seam formation and the mechanical behavior of flexible films, enabling the optimization of sealing processes for improved package performance. Full article

(This article belongs to the Special Issue Polymers for Circular Packaging Materials)

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15 pages, 2442 KB

Open AccessArticle

Preparation and Characterization of Copper-Crosslinked Alginate–Hyaluronic Acid Aerogels as Potential Wound Dressing Materials with Enhanced Antibacterial Properties

by Tamara Athamneh, Mohammad A. A. Al-Najjar, Raghad Garafat, Alaa Mahmood Abuawad, Areen Alshweiat, Muna Barakat, Wael Fatehi Abu-Irmaileh, Adel Maher Hamdan, Tasneem Ali Odat, Razan Altarabeen, Yamen Bani Younes and Irina Smirnova

Polymers 2025, 17(17), 2406; https://doi.org/10.3390/polym17172406 - 4 Sep 2025

Viewed by 597

Abstract

The development of advanced wound dressing materials with enhanced antibacterial properties is critical for improving patient outcomes and reducing infection risks. This study introduces a novel bio-based aerogel composed of copper-crosslinked alginate and hyaluronic acid, synthesized using supercritical gel drying techniques. Alginate and [...] Read more.

The development of advanced wound dressing materials with enhanced antibacterial properties is critical for improving patient outcomes and reducing infection risks. This study introduces a novel bio-based aerogel composed of copper-crosslinked alginate and hyaluronic acid, synthesized using supercritical gel drying techniques. Alginate and hyaluronic acid polymers are widely used in the pharmaceutical and medical industries because of their nontoxicity, biodegradability, and biocompatibility. This study aimed to create an aerogel that could be used as a potential wound dressing material by crosslinking hyaluronic acid and alginate with copper. The bio-based aerogel was prepared by ionic gelation and supercritical gel drying. The prepared materials were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), BET surface area analysis, and energy-dispersive X-ray fluorescence (XRF). Moreover, the aerogel wound dressing properties were evaluated in terms of fluid uptake and antibacterial activity against S. aureus and E. coli. The physicochemical characterization of the prepared aerogels revealed their unique structural and morphological features, which are influenced by copper ion concentration and crosslinking time. Regarding their wound dressing evaluation, both aerogel and hydrogel were found to have antibacterial properties when tested on S. aureus with inhibition zones of (36 mm, 23 mm) and E. coli (31.6 mm, 21 mm) for hydrogel and aerogel, respectively. Also, excellent fluid uptake was found to reach up to 743%. These findings underscore the potential of copper-crosslinked alginate–hyaluronic acid aerogels as innovative wound dressing materials that combine superior antibacterial efficacy with excellent fluid management, paving the way for improved wound healing solutions. Full article

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

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22 pages, 10983 KB

Open AccessArticle

Effect of Freeze–Thaw Cycles (FTCs) on the Mechanical Behavior of Highway Clay Subgrade Soils Stabilized with Lime and Polypropylene Fibers

by Tayfun Şengül and Yaşar Vitoşoğlu

Polymers 2025, 17(17), 2405; https://doi.org/10.3390/polym17172405 - 4 Sep 2025

Viewed by 487

Abstract

High-plasticity soils pose significant problems in road infrastructure, adversely affecting structural safety due to their unfavorable engineering properties. Lime stabilization is one of the most widely used methods for improving such soils. However, lime addition may cause brittleness of these soils, resulting in [...] Read more.

High-plasticity soils pose significant problems in road infrastructure, adversely affecting structural safety due to their unfavorable engineering properties. Lime stabilization is one of the most widely used methods for improving such soils. However, lime addition may cause brittleness of these soils, resulting in a sudden loss of strength. To overcome this weakness, this study investigated using polypropylene fibers in combination with lime stabilization. Accordingly, the plasticity, compressibility, and strength properties of soil mixtures containing 3%, 6%, 9%, and 12% lime, along with mixtures prepared with a constant 0.5% polypropylene fiber content, were systematically evaluated in a laboratory environment. Additionally, the influence of freeze–thaw cycles (FTCs), which induce long-term strength degradation in highway subgrades, on these mixtures was investigated. The results indicated that lime addition reduced the plasticity index by up to 38% without causing a significant change in dry unit weight. It was also determined that FTCs could lead to a strength loss of up to 84% in natural soil, and this loss was substantially reduced by adding lime and fibers. These findings highlight that the lime-fiber combination represents an effective and sustainable method for increasing the performance of high-plasticity soils. Full article

(This article belongs to the Section Polymer Fibers)

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16 pages, 2351 KB

Open AccessArticle

Development of Cu@Zr-MOFs-PAN Nanofiber Composites for Efficient Methylene Blue Adsorption in Wastewater Treatment

by Zibin Li, Lizhen Zhang and Guoyuan Yuan

Polymers 2025, 17(17), 2404; https://doi.org/10.3390/polym17172404 - 3 Sep 2025

Viewed by 328

Abstract

Methylene blue (MB) is a commonly used dye that generates a large amount of dye wastewater during its application. If discharged untreated, it poses a serious threat to water environments and human health. Therefore, the removal of methylene blue from dye wastewater is [...] Read more.

Methylene blue (MB) is a commonly used dye that generates a large amount of dye wastewater during its application. If discharged untreated, it poses a serious threat to water environments and human health. Therefore, the removal of methylene blue from dye wastewater is crucial. In this study, we used zirconium-based metal–organic frameworks (Zr-MOFs) as a precursor and doped them with copper ions to prepare the Cu@Zr-MOFs composite material. Subsequently, we fabricated Cu@Zr-MOFs-PAN nanofiber composites through electrospinning to address the challenge of separating Cu@Zr-MOFs from water. The results indicate that the introduction of copper ions significantly enhances the adsorption capacity of Zr-MOFs for MB, increasing the adsorption amount from 158.0 mg/g to 266.0 mg/g, representing a 68.3% improvement. Furthermore, the prepared Cu@Zr-MOFs-PAN nanofibers exhibited an MB adsorption capacity of 162.1 mg/g, further confirming the successful preparation of Cu@Zr-MOFs-PAN. X-ray photoelectron spectroscopy (XPS) analysis shows that copper doping not only enhances the structural stability of the material but also increases the density of active sites for MB adsorption. This study not only provides an efficient material for the removal of MB from wastewater but also offers an important theoretical basis for the design of novel nanomaterials for environmental pollutant remediation. Full article

(This article belongs to the Section Polymer Fibers)

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Polymers, Volume 17, Issue 17 (September-1 2025) – 166 articles

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